Showing posts with label hurricane ike. Show all posts
Showing posts with label hurricane ike. Show all posts

Wednesday, January 14, 2009

Yellowstone Lake Earthquake Swarm Summary as of 8 January 2009

UPDATE: "CHICAGO NWS": Snow and Blowing Snow Today Followed by Dangerous Wind Chills

Local Storm Reports

Yellowstone Lake Earthquake Swarm Summary as of 8 January 2009

Seismic activity at Yellowstone Lake in Yellowstone National Park increased in late December 2008.

As of January 8, 2009, the seismic activity has markedly decreased

(Listen to a podcast with YVO's Scientist-in-Charge about the recent swarm).

It is possible that the swarm has ended, although a return of activity may occur as previous Yellowstone swarms of this size have lasted for tens of days to many weeks. Swarms are common at Yellowstone.

The last notable swarm occurred in 2004, please see our 2004 article, Yellowstone Earthquake Swarms for more background on earthquakes and swarms at Yellowstone.

Seismologists continue to review the earthquakes

About 900 earthquakes occurred between Dec. 26, 2008 and Jan. 8, 2009 in the Yellowstone Lake area. Five hundred of the earthquakes (including all greater than magnitude 2.0) have been reviewed by seismologists. There were 111 earthquakes with magnitudes greater than 2.0 (> M2.0)and 18 earthquakes > M3.0. About 400 smaller earthquakes have yet to be reviewed. [A new Frequently Asked Question about earthquake analysis will be posted here soon]. The largest earthquake during the swarm was a magnitude 3.9 on Sunday, December 28, 2008. One of the analyses seismologists use to talk about earthquakes and swarms is the cumulative seismic moment, which is a measure of the earthquake energy. The cumulative moment (the energy from all the analyzed earthquakes in the swarm) for the Yellowstone Lake Swarm is equal to the energy of a single magnitude 4.5 earthquake (see Image 3).

Depths for shallow earthquake hypocenters (the point within the earth where an earthquake rupture starts) are difficult to determine accurately unless the seismic stations are spaced much more closely than those in the Yellowstone Seismic Network. The best located earthquakes have hypocenters (depths) of 3 to 10 km (1.8 to 6.0 miles). From Dec. 26 through Jan 2, the hypocenters appear to have migrated northwards, starting southeast of near Stevenson Island, with many of the latest events occurring near Fishing Bridge.

Image 2. The depth versus location of the Yellowstone Lake earthquake swarm from X to X' on the Yellowstone Lake map. Earthquakes are shown from Dec. 27, 2008 (blue) to Jan. 8, 2009 (red). The M 3.0 and greater earthquakes are shown as stars, the smaller earthquakes are shown as circles. Click on the image for a full-size version.

Swarms are normal at Yellowstone

The recent swarm is well above typical activity at Yellowstone. Nevertheless it is not unprecedented during the last 40 years of monitoring. Earthquake swarms within the Yellowstone caldera are typical, with magnitudes occasionally ranging above 4.0. The 1985 swarm on the northwest rim of the caldera lasted for three months, with earthquakes up to M4.9 and over 3000 total events recorded.

The magnitudes of earthquakes in this swarm range from zero to 3.9. Earthquakes with magnitudes less than 3.4 are generally not felt by people unless they are very shallow and you are standing very close to the epicenter (point on the earth's surface above the hypocenter). For perspective, earthquakes of magnitude 3.4 to 4.5 are often felt and there were multiple reports of felt earthquakes during this swarm. A magnitude 5 or greater is generally required to produce damage to buildings or other structures.

Image 3. Number of reviewed Yellowstone Lake earthquakes in six-hour and three-hour intervals from 12/27/08 to 01/06/09. The green line on the left figure gives the cumulative number of earthquakes; the steep slopes correspond to increase in earthquake number. The red line in the figure on the right gives the cumulative moment, or energy; its sharp increase in the first few days is due to a greater number of large earthquakes with their greater energy release. The total cumulative moment is equivalent in energy to about one M 4.5 earthquake. Click on the image for a full-size version.

New equipment allowed us to monitor the swarm

Improved volcano and seismic monitoring at Yellowstone gives us a greater ability to locate earthquakes, understand their source process and identify anomalous sources of seismic activity. New equipment including precise measurements of ground motion by GPS receivers and borehole strainmeters provided by the National Science Foundation's EarthScope and Continental Dynamics Program have been used extensively during the last week of intense earthquake activity. Ground motions accompanying the swarm, from the GPS instruments will take two or more weeks to fully process.

It is worth noting that in 2004 the Yellowstone caldera began a period of accelerated uplift measured by GPS instruments that was as large as 7 cm/yr (2.7 inches/yr), three times as fast as recorded in the recorded history but has now reduced to about a maximum rate of 4 cm/yr. Scientists have modeled this deformation as due to magmatic recharge of the Yellowstone magma chamber at a depth of ~10 km (6 miles). The area of the swarm is on the eastern side of the uplift area. For more information on the uplift, please see our article Recent ups and downs of the Yellowstone Caldera.

There are several causes for earthquakes

Earthquakes at Yellowstone are caused by a combination of geological factors including: 1) regional stress associated with normal faults (those where the valleys go down relative to the mountains) such as the nearby Teton and Hebgen Lake faults, 2) magmatic movements at depth (>7 kms or 4 miles), and 3) hydrothermal fluid activity caused as the groundwater system is heated to boiling by magmatic heat.At this time, no one has noted any anomalous changes in surface discharges (hot springs, gas output, etc.).

We continue to monitor Yellowstone Volcano

YVO staff from the USGS, University of Utah and Yellowstone National Park continue to carefully review all data streams that are recorded in real-time. At this time, there is no reason to believe that magma has risen to a shallow level within the crust or that a volcanic eruption is likely. The USGS Volcano Alert Level and Aviation Color Code for Yellowstone remain at Normal and Green.

Yellowstone National Park is evaluating infrastructure near the north end of Yellowstone Lake to assess if any damage has occurred to facilities. Winter visitor activities and staff operations have not been impacted and continue as normal.

The Yellowstone Volcano Observatory (YVO) is a partnership of the U.S. Geological Survey (USGS), Yellowstone National Park, and University of Utah to strengthen the long-term monitoring of volcanic and earthquake unrest in the Yellowstone National Park region.

Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

WEATHER NOTE

Ike post-mortem: Experts disassemble monster storm's causes
By
SARAH MOORE
January, 9, 2009

Photos of coastal Texas before and after Hurricane Ike give a sort of "now you see it; now you don't effect, as if Ike were playing David Copperfield with beach houses.

Ten houses in Jamaica Beach. Ninety-one houses from Crystal Beach. All but five from Gilchrist.
As longtime meteorologist and former director of the National Hurricane Center Neil Frank clicked through a Power Point presentation, it brought back the initial feeling of disbelief and sadness at the profound alteration of previously idyllic beach communities.

At a conference Friday at University of St. Thomas in Houston, "Understanding Ike, does size matter," experts from various fields gathered to share information on Hurricane Ike, the baffling storm that was the third most destructive in American history, despite its Category 2 designation.

With Texas hit by named storms Dolly, Edouard and Ike last year, residents are left wondering what's going on.

But if it seems like hurricanes have become more frequent and more intense than they used to be, resist the temptation to jump to conclusions about global warming, some meteorologists say.

A number of factors contribute to that impression.

Because storms are rated based on wind speed, rather than barometric pressure, some systems reach named status al-though they lack the low pressure that would allow them to develop into a tropical cyclone, Frank said.

"On the basis of (barometric) pressure, not wind, (Ike) would have been called a Category 3," he noted.

In addition, satellites record more storms out at sea that in the past would have gone undetected.

"Historic records are not adequate to say man-made global warming is causing more storms," Frank said.

And some of it is just that too much time has passed.

In an active period between the 1930s and 1960s, 12 named storms hit Texas.
Frank also cited destructive storms in 1875 and 1893, as well as the storm that killed up to 10,000 in Galveston in 1900 and another major storm in 1915.

Also at the conference, Shell Oil spokesman Stuart Furgang described the destructive impact of various storms in re-cent years as well as how the company copes with the disruption. Furgang described the way personnel were evacuated in stages, leaving behind a last crew to "turn off the lights" only leaving at the very last minute - or staying to keep the operation going should the storm turn.

He described platforms that endured hours of 175 mph winds during Hurricane Katrina in 2005 and 52-foot waves lashing platforms during Ivan in 2004.

Lt. John Moran of the U.S. Coast Guard showed video and told of photo-finish rescues of people stranded in pickup trucks nearly engulfed by Ike's storm surge as the helicopter grew low on fuel and waves threatened to sweep stranded families into the Gulf.

But there were lighter moments, too.

Conference attendees laughed as Manuel Gonzalez of CenterPoint Entergy dubbed Ike a "Category Tree" because of the large number of trees the storm blew into power lines.

MARITIME NOTE

Heroics of wireless operator remembered

A CENTURY after the first ever rescue at sea using a radio, enthusiasts from the Marconi Wireless Station in Cornwall are to celebrate the remarkable event.

The incredible operation was totally overshadowed by the Titanic disaster and the heroes involved have been largely forgotten. Radio operator Jack Binns saved nearly 2,000 lives after his ship RMS Republic started sinking after it was rammed by another in thick fog in the north Atlantic in 1909.

After the collision, the Marconi-trained operator leapt to his post and began tapping out "CQD" in Morse code – the distress signal used before SOS was adopted.

He worked tirelessly for 36 hours in the wireless room which had a hole in the wall made by the bow of the other vessel, the SS Florida.

His signals were picked up 30 miles away by operator Jack Irwin on Nantucket Island, off the coast of Massachusetts.

Mr Irwin immediately realised the importance of the distress call and replied to the message – sparking one of the greatest ever rescues at sea.Mr Binns was then handed a note from Captain Inman Sealby to be broadcast. It read: "Republic rammed by unknown steamship, 26 miles southwest of Nantucket. Badly in need of assistance."

Through Mr Irwin, whose range was much further, Mr Binns learned two ships were aware of the collision and in the general area. However, the operation was a long-drawn-out affair because the rescue ships found it hard to locate the stricken vessel due to the fog and a lack of lights on the White Star liner Republic.

As they awaited rescue, Cpt Sealby decided to transfer his passengers to the Florida, which was not sinking despite her crumpled bow.

She already had nearly 1,000 people on board, many of them refugees from the Messina earthquake in Italy.

After the high-risk operation, the sinking Republic was left with just 44 crew from her total of 300 – and more than 400 passengers had been transferred in dangerous conditions. Using location bombs and fog horns, the rescue ship Baltic finally found the Republic and the last part of the rescue began. Mr Binns stayed at his post until the last possible moment. He sent more than 200 messages, the last being: "Current going, wireless now closed."

Following naval tradition Cpt Sealby and the first mate stayed on board and went down with the Republic – both, however, were picked up.

During the incredible operation coordinated by wireless, no-one was lost. The only casualties were two deaths during the initial collision.

Englishman Mr Binns was hailed a hero on his return to New York, where the voyage had begun. Thousands lined the streets, shouting: "It's CQD Binns!" The incredible rescue and Mr Binns' heroism were totally overshadowed by the Titanic sinking three years later.

Ironically, Mr Binns later turned down the opportunity of being the Titanic's wireless operator and instead pursued a career in journalism. Wireless societies on both sides of the Atlantic will be on air on January 23 to celebrate hero Mr Binns and mark the centenary of the rescue.

David Barlow, a Marconi historian from the Radio Officers' Association who runs the Marconi Wireless Station at the Lizard, has researched the events surrounding the rescue. He said: "Mention 'distress' and 'wireless' and the first name on the lips is Titanic. But the events three years previously were of far greater significance and used the distress call CQD.

"It is a privilege to take part in an event to celebrate the saving of over 1,600 lives through the medium of wireless. Our special call sign GB100MSC represents the station that received the CQD sent by Jack Binns 100 years ago.

"Since that date, wireless operators and radio officers have remained on board stricken ships with their captains in both peace and war time, often at the cost of their lives." John Robinson Binns – known as Jack – was born in poverty in Lincolnshire and raised in Peterborough.

He attended the Marconi training school in 1904 and then joined his first ship as a wireless operator, aged 20.

Mr Barlow said: "In 1908 he joined RMS Republic and was the only wireless operator on board. At 5.40am on January 23, 1909, Binns became aware that the fog horn was sounding more frequently and felt the judder of the engines stopping.

"Then he heard a loud crash and the ship keeled over. He rushed to the wireless room and could see another ship through a hole in the wall.

"Using his Morse key he sent the message CQD CQD CQD MKD MKD MKD – MKD was the call-sign of the Republic.

"Operator Jack Irwin, on Nantucket Island, picked up the message and was soon in contact with the SS Baltic, which was only 64 miles away from Republic.

"However, she sailed over 200 miles trying to find the stricken vessel and travelled very slowly because her captain was worried about further collisions in the fog.

"The Baltic used location bombs in a bid to find the Republic, but when she was down to her last one the wireless was used to co-ordinate efforts.

"The bomb was heard and 15 minutes later the Baltic hove to."

Virginia Lovelace, Jack Binns' American granddaughter, remembers her grandfather well and called him "Binnsy".

She said: "My family are so grateful to the radio amateurs who will use the airwaves to mark this important centenary, in which more lives were saved than were lost on board the Titanic."

Jack Binns died in New York in 1959, aged 75. He spent the war in Canada as an instructor in aviation and wireless.


RS

Wednesday, January 7, 2009

NOAA models tsunami warning system

NOAA models tsunami warning system

High-resolution computer models of Oregon’s coastline that simulate tsunamis and floods have been developed by scientists at the National Oceanic and Atmospheric Administration, the agency announced Dec. 10.

Emergency managers will use the models to create evacuation and rescue plans for potential incidents, agency officials said, adding that the digital elevation models were developed by NOAA’s National Geophysical Data Center and the Cooperative Institute for Research in Environmental Science.

The models cover the Oregon coastal area from Port Orford to the Columbia River.


The digital elevation models provide a framework that allows scientists to forecast the magnitude and extent of coastal flooding caused by a tsunami or storm surge with greater accuracy than older models, NOAA said. Since 2006, scientists have created 28 digital elevation models of U.S. coastal areas and an additional 45 digital elevation models are planned for the future.

The coastal digital elevation models are part of the U.S. Tsunami Forecast and Warning System and the new Oregon models will assist the Oregon Department of Geology and Mineral Industry map tsunami evacuation zones, the agency said.

NOAA’s Pacific Marine Environmental Laboratory in Seattle incorporated the models into distant tsunami model scenarios, the agency said, adding that the scenarios simulate offshore earthquakes, the resulting tsunami that travels across the Pacific Ocean, and the potential floods when the tsunami reaches the coast.

With that information, NOAA's Tsunami Warning Centers can issue more accurate flooding forecasts if an earthquake triggers an actual tsunami, agency officials said.

WEATHER NOTE

Insurers' natural disaster losses rise in 2008
Overall losses from Gustav and Ike were about twice the insured losses.


By Geir MoulsonASSOCIATED PRESS
Tuesday, December 30, 2008

Insurers' losses from natural disasters rose by about 50 percent in 2008, with Caribbean hurricanes Ike and Gustav powering the increase and climate change increasingly becoming a factor, a leading reinsurer said Monday.

Munich Re AG said in an annual review that insured losses came in at $45 billion this year, up from nearly $30 billion in 2007. It said total economic losses, including losses not covered by insurance, leapt to $200 billion from last year's $82 billion.

That increase was due in part to the devastating earthquake that hit China's Sichuan province in May. Munich Re said the quake caused overall losses of $85 billion — by far the year's biggest — but insured losses of only $300 million.

Munich Re said the year was marked by high losses from weather-related natural disasters, continuing a long-term trend.

"Climate change has already started and is very probably contributing to increasingly frequent weather extremes and ensuing natural catastrophes," board member Torsten Jeworrek said in a statement.

"These, in turn, generate greater and greater losses because the concentration of values in exposed areas, like regions on the coast, is also increasing further throughout the world." The company noted that six named storms — Dolly, Edouard, Fay, Gustav, Hanna and Ike — reached the U.S. coast this year after two years in which the American mainland was largely spared.

The year's most expensive event for insurers was Hurricane Ike, which hit the Caribbean and the southern United States in September, causing insured losses of $15 billion. In second place was Gustav, which hit shortly before and caused losses of $5 billion.

In both cases, the overall losses were about twice the insured losses.

Munich Re said an unusually severe snow- and ice-laden cold spell in China in January and February, which hit roads, railways and electricity supplies, cost insurers $1.6 billion. That's well short of the overall economic losses, which it estimated at $21.1 billion.

A winter storm that hit central Europe in early March cost insurers some $1.5 billion. Munich Re said an unusually severe U.S. tornado season, with a total of 1,700 tornadoes, also proved costly. A series of tornadoes that killed 12 people in late May generated insured losses of more than $1.3 billion.

The year's deadliest disaster was Cyclone Nargis, which devastated coastal areas in Myanmar in early May, killing nearly 85,000 people. Munich Re put overall economic losses at $4 billion but gave no figure for insured losses in the isolated country.

Though they rose sharply for the second consecutive year, this year's insured losses were still well short of the $99 billion Munich Re recorded in 2005, when losses were swollen by claims from Hurricane Katrina in New Orleans.

The company said that year also saw a record overall economic loss of some $232 billion, adjusted for inflation.

As a reinsurer, Munich Re offers backup policies to companies that write primary insurance policies.

Reinsurance helps spread risk so that the system can handle large losses from natural disasters.

Top News of the Day from NWS Chicago!

Top 10 Weather Events for 2008 for Northern Illinois and Northwest Indiana (pdf)
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Headed to Washington DC for the Presidential Inaugural? Click Here for Weather Information


MARITIME NOTE

Can other vessels see you on radar?

http://images.aad.gov.au/img.py/20ae.jpg

It is important that skippers of radar-equipped vessels know the capability of their own radar to detect other vessels in order to avoid collisions. However, it is critical for skippers of all vessels to know if radar on another vessel can detect their own vessel. This is especially important as weather deteriorates and visibility decreases. The range at which a vessel can be detected by radar depends on many variables, such as the radar power, antenna, the vessel’s radar cross section (how strongly it reflects radar), and the environmental conditions (weather, waves, rain, fog, etc.) Nominal detection range in ideal conditions

Keeping a sharp eye on the radar for other vessels is key, but making sure your boat can be seen by the radars of other vessels is important too. (Beau Rogers) Marine radar encompasses small recreational systems transmitting at between 2 kW and 4 kW, to professional systems transmitting between 12 kW and 50 kW. Radar cross section (RCS), expressed in square meters (m2), measures how strongly a target reflects radar pulses. Radar detects larger RCS targets with less power, at longer range, and in more severe weather conditions.

Targets addressed in this article range from one square meter RCS (1 m2) for a person or small inflatable to about 10 m2 for a large recreational vessel, with 5 m2 being representative of pleasure boats. The accompanying table summarizes maximum detection ranges in clear weather for typical marine radars and targets. While detection may occur at greater ranges than shown in certain circumstances, most of the time environmental conditions and weather limit detection to shorter ranges. The table indicates that low-power radar on a pleasure vessel will usually not detect another pleasure craft at much more than one mile, whereas a commercial ship will not detect a pleasure boat at more than four to five miles, in good weather.

Large, ocean-going ships with powerful scanners might double this. If these detection ranges seem short, remember that recreational vessels are small, both physically and as reflectors of radar pulses. For example, the radar cross section of a Navy cruiser, which is not an especially large ship, is about 160,000 m2. It is huge compared with the typical 5 m2 pleasure boat.

Other things being equal, radar that detects a cruiser at 10 miles will not detect a pleasure sailboat at more than one mile. The table also shows the difference between the typical 48-mile recreational radar (4 kW) and the typical 16 or 24-mile radar (2 kW). The greater maximum range is useful only for detecting high cliffs when far out at sea, or storm clouds at altitude, as anything on the surface beyond 16 miles would be well below the radar horizon and undetectable. The main difference is that greater power usually comes with a better antenna and more sensitive electronics, resulting in a three-fold improvement in detection range (everything else being the same).

Flat seas decrease range Detecting a vessel in perfectly calm water is more difficult than detecting it in moderately rough seas. Although this is counter-intuitive, detection in a seaway is complicated because every pulse transmitted by the scanner goes to the target over two paths. One path is direct from the antenna to the target; the other path includes reflection from the water. The two pulses combine at the target with the result that power delivered to the target may be quite different from what would be the case in the absence of reflection from the water.

One effect of this multipath pulse cancellation is to reduce maximum detection range for targets on the surface of the water. Since most of the radar-reflecting elements of a small boat are in the hull, close to the water, maximum detection range for a pleasure vessel in smooth water is much shorter than given in the table; roughly a third. Multipath pulse cancellation decreases as the seas build and the ranges shown in the table become more accurate as seas reach about seven feet. The thing to remember is that flat-sea maximum detection ranges are much shorter than shown in the table. Fog attenuates radar

Rain, fog and sea state all affect your ability to see other vessels. In poor conditions, detection range can be significantly reduced. (Beau Rogers) Fog attenuates the radar signal and reduces detection range. How much the fog reduces detection range depends on the visibility distance, scanner power, and the extent of fog between scanner and target. Here we assume that fog extends over the entire distance between scanner and target vessel. When the maximum detection range in clear weather is short to begin with, for example, the target vessel is small, or the radar on the other vessel is a low-power recreational system, percentage reduction in detection range does not mean much in absolute terms.


For example, fog with six-meter visibility reduces detection range of two miles in clear weather to 1.5 miles, an absolute reduction of half a mile. On the other hand, when the maximum detection range in clear weather is long, for example, the target vessel’s RCS is large, or the radar on the other vessel is a high-power professional system, percentage reduction in detection range is far more significant. Fog with six-meter visibility reduces 10-mile detection range in clear weather to less than four miles, a six-mile reduction. Sea-clutter limits detection Waves produce target-masking clutter. Since waves cover a large area of the sea, they produce numerous blips covering a large area of the display.

These mask returns from useful targets like your vessel by filling up, or cluttering the display with blips due to waves. While the radar operator can adjust controls to minimize the visual cluttering effect, reliable target detection is possible only if the target produces a stronger return than the nearby waves. The operator simply decreases the gain until the clutter disappears, leaving blips representing desired targets. Of course, this works only if the target is stronger than the clutter.

That is, the target must stand out against the background clutter. Scanner power is irrelevant, since increasing power simply increases both clutter return and target return the same amount. Waves reflect radar pulses when the wave face is perpendicular to the radar beam. The distance from the scanner at which the waves are perpendicular to the radar beam is proportional to wave height and to the height of the scanner.

The strength of the reflection, i.e. the effective RCS of the sea surface, depends on the wave height and distance from the scanner. It peaks at a certain sea-clutter limit distance, which depends on the antenna height and sea state. The radar return from more distant waves becomes insignificantly small. At shorter distance, the radar return from waves remains roughly constant. Usually the wave clutter appears in the direction from which the waves approach, generally to windward. Five-foot waves produce a sea-clutter limit of about a half mile around a scanner 10 feet above the waterline. Doubling the wave height or doubling the antenna height each doubles the clutter limit. The same five-foot waves that produce a half-mile clutter limit around a pleasure powerboat might produce a two-mile clutter limit around a small ship with scanner 30 feet above the water, and out to six miles for a very large ship.

Skippers of radar-equipped pleasure boats used to seeing a small area of sea-clutter on their radar display must understand that a large ship experiences a much larger clutter limit due to the scanner height. Summarizing the effect of sea-clutter on detection range is difficult because of the dependence on antenna height and wave height. Generally, the larger radar systems are generally on larger ships and are higher, so the clutter ring is larger. Consequently, you will disappear into the clutter at greater range from a large ship than from a recreational vessel. You should remember that detection of your vessel outside the sea-clutter limit ring is determined by signal power (i.e. RCS, transmitter power, distance, and attenuation from fog and rain). Sea-clutter limits detection inside the clutter ring.

Waves can cause shadows Since most of the reflecting material in a pleasure boat is in the hull, waves larger than a vessel’s freeboard can shadow the vessel whenever it is in the trough between waves. The vessel can be detected only when it is on the crest of a wave; it will be masked and undetectable when in a trough. The resulting intermittent detection makes it difficult for a human radar operator to see the vessel’s radar blip and virtually impossible for automated systems like ARPA to detect and track it. Rain attenuates radar pulses Rain and other precipitation such as snow and sleet reduce detection range in two ways.

First, rain attenuates the radar pulses just as fog does. The difference being that the amount of rain is described as rainfall rate in millimeters per hour (mm/h), rather than as visibility range. Second, rain produces clutter return similar to wave clutter. When rain surrounds the target, clutter is invariably the dominant factor rather than attenuation. Since the clutter return is proportional to the amount of rain (and the rainfall rate) in the volume of space covered by the beam, and the beam fans out with range, there is always a rain-clutter-limited-detection-range that depends only on the rainfall rate and target RCS. Beyond this limit, you will not be detected. Closer than this limit, you may be detected if range and attenuation don’t prohibit it. The key concept is that detection is possible only at ranges shorter than the rain-clutter limited detection range, which depends only on the rate of rainfall.

The classic radar reflector for smaller yachts is the corner reflector mounted in the “catch rain” orientation in the rigging often from a spreader. (John Snyder) Consider a large recreational vessel target and a small professional 12 kW radar. In clear weather, the target may be detected at five and a half miles. If rain surrounds the target, detection range is clutter-limited to slightly less than three and a half miles by drizzle and to slightly more than one mile by light rain. Moderate or heavier rain limits detection to less than half a mile. Rain surrounding the vessel severely restricts detection. Even light rain will limit detection in most cases to little more than a mile. A high-power professional radar will do better, because the beam width is narrow and it is less affected by rain-clutter.

You should remember that detection of your vessel inside the rain-clutter limit ring is determined by signal power (i.e. RCS, transmitter power, distance, and attenuation from fog and rain). Rain-clutter limits detection outside the clutter ring. Pleasure vessels are not strong radar targets, multipath pulse cancellation limits detection range in calm sea conditions, shadowing limits detection when the waves are larger than the freeboard, and the radar horizon is limited because the target is on the surface. Fog and rain attenuate the signal and reduce the probability that a pleasure vessel is detected.

Clutter from waves and rain may make detection impossible regardless of the scanner power. As skipper of a pleasure vessel in good weather and calm seas, you may think in terms of being detected by low-power recreational radar at half a mile or so and by professional radar on a large ship at four miles or so. Detection range improves about three to one as the seas build to seven feet or if a good radar reflector is mounted on the vessel. Other than that, darkness, light drizzle, moderate fog, and waves up to three feet have little effect on detection range.

This reflector on the stern will provide some reflectivity, but won’t greatly increase radar visibility. (John Snyder) Detection in bad weather is problematic. Thick fog and drizzle extending over large areas may attenuate the radar signal greatly and reduce detection range severely. If the rain surrounds your vessel, clutter restricts detection to ranges shorter than the rain clutter limit range, which is about one mile in light rain, half a mile in moderate rain, and even shorter in heavier rain.

This is independent of the radar. Detection range may be better if your vessel is large, or if you have a good radar reflector, but the skipper of a recreational vessel should not count on being detected at more than half a mile in moderate rain. Waves generate a clutter limit. Outside the clutter limit, wave clutter has little effect on detection. Inside, detection is possible only if the target is larger than the wave clutter. Three-foot waves are not much of a problem. Five-foot waves require a moderately large radar reflector; eight-foot waves require about 10 m2; 10-foot waves probably preclude detection entirely. The sea-clutter limit is proportional to antenna height and sea state; the larger ships, i.e. higher antennas, experience the larger clutter rings, up to several miles. Detection range may be better if your vessel is large or if you have a good radar reflector, but the skipper of a recreational vessel should not count on being detected at less than a mile in eight-foot waves. It does not take much in the way of rain or waves to limit detection of a pleasure boat to a mile or less.

A vessel approaching at 20 knots would have no more than three minutes to detect you, identify you, track you and determine risk of collision, and decide on a course of action. A large vessel wouldn’t be able to avoid you under these constraints.

Your best option is to proceed with caution in bad weather.

RS

Wednesday, November 19, 2008

Simulation Shows What Would Happen If Magnitude 7.8 Earthquake Hit California

Simulation Shows What Would Happen If Magnitude 7.8 Earthquake Hit California

ScienceDaily (Nov. 10, 2008) — The 2,000-strong community of Census of Marine Life scientists from 82 nations has announced astonishing examples of recent new finds from the world’s ocean depths. Mollusk expert Patricia Miloslavich (Venezuela), Census co-senior scientist: “We are beginning to pull together a picture and clarify the complicated and interconnected global drivers of marine biodiversity patterns and changes, and we are starting to see the conservation-related implications and benefits, from the small coves of the near-shore to the vast abyss.”

Antarctic ancestry of many deep-sea octopuses worldwide

Within their mandate "to assess and explain the diversity, distribution, and abundance of marine life in the oceans – past, present, and future,” Census of Antarctic Marine Life scientists report the first molecular evidence that a large proportion of deep sea octopus species worldwide evolved from common ancestor species that still exist in the Southern Ocean.

Octopuses started migrating to new ocean basins more than 30 million years ago when, as Antarctica cooled and a large icesheet grew, nature created a “thermohaline expressway,” a northbound flow of tasty frigid water with high salt and oxygen content.

Isolated in new habitat conditions, many different species evolved; some octopuses, for example, losing their defensive ink sacs – pointless at perpetually dark depths.

This revelation into the global distribution and diversity of deep sea fauna, to be reported Nov. 11 in the journal Cladistics, was made possible by intensive sampling during Census International Polar Year expeditions.

Other findings are listed below.

Distribution of sea life

Scientists discover both a “White Shark Café” and a “sturgeon playground” in the Pacific, as others explore life on a “new continent” in the mid-Atlantic, in oceanic canyons, around Earth’s deepest hot vents, and in the world’s coldest, saltiest seawater;

Deep sea diversity

Deep sea explorers discover new forms of life, including behemoth bacteria, colossal sea stars, astonishing Antarctic amphipods and a mammoth mollusk, and find familiar species in many new places. Experts also estimate that, beyond the 16,000 marine fish species already known to science, another 4,000 await discovery, many of them in the tropics.

Abundance

Researchers find a sea floor carpet of bugs and a city of brittle stars, and document bluefin tuna abundance in the early 1900s by scouring fishery reports, fishing magazines and other records.

Meanwhile, the Ocean Biogeographic Information System has grown to include more than 120,000 species. And a rapidly-expanding reference library of DNA barcodes of marine species recently helped reveal inaccurate labeling of sushi in New York City and elsewhere.

As well, the national and regional networks expediting much of the Census work expanded from 10 to 12 since 2006. They and the field projects of the Census established precedent-setting ethical standards for marine research.

As more than 700 delegates gather for the World Conference on Marine Biodiversity (Valencia, Spain Nov. 11-15), organized by the Census’s European affiliate program on Marine Biodiversity and Ecosystem Functioning, the report details major progress towards the first ever marine life census, for release in October, 2010.

Other research highlights

1) Exploring a “new continent” in mid-Atlantic: MAR-ECO (http://www.coml.org/descrip/mareco.htm) scientists describe their work as “surveying a new continent half way between America and Europe.” Sampling along the Mid-Atlantic Ridge at depths down to 2,500 meters, they find many hundreds of species rare or unknown elsewhere in the world and collect environmental data to help explain their distribution and abundance.

2) World’s deepest known active hot vent: ChEss (http://www.coml.org/descrip/chess.htm) scientists in the Mid-Atlantic Ridge explore the world’s deepest known active hot vent, field named Ashadze, over 4,100 meters deep, dominated by anemones, polychaete worms and shrimp. They also discover marine environments with little or no oxygen harboring more life than expected.

3) Bacterial mats in Black Sea: ChEss scientists also find reefs deep in the Black Sea made of bacterial mats using methane (natural gas) as an energy source, the bacteria forming spectacular chimneys up to four meters high. Such reefs could contribute key insights into mechanisms controlling emissions of methane, an important greenhouse gas, from the ocean to the atmosphere.

4) Brittle Star City: Exploring off the coast of New Zealand, CenSeam (http://www.coml.org/descrip/censeam.htm) researchers capture images of a novel “Brittle Star City,” whose inhabitants colonize the peak of a seamount – an underwater summit taller than the world’s tallest building. In a swirling circumpolar current flowing at roughly four kilometers per hour, tens of millions of brittle stars live arm tip to arm tip. The current kept away would-be predators while delivering an ample supply of food that residents of Brittle Star City collected simply by raising their arms.

5) Surprisingly different twins: NaGISA (http://www.coml.org/descrip/nagisa.htm) nearshore scientists in the Alaskan Arctic find a site with a rocky seafloor, rare along the normally soft and silty Arctic coastline. The hard substrate hosts a highly diverse community compared to surrounding soft bottom habitat. Comparison of this new site to a similar site surveyed by Census researchers in 2002 shows surprisingly different communities. Census nearshore scientists collaborating with local agencies also discover new species in the Aleutian archipelago, including a kelp, sea anemones, chitons, snails, and sea stars.

6) Pacific hotspots: TOPP (http://www.coml.org/descrip/topp.htm) researchers discover eddies of warm water in the Pacific may meld, forming hotspots in the open sea that support elevated levels of tiny phytoplankton that form the base of the marine food web. These green meadows in the vast Pacific in turn concentrate species from all tiers of the food web – from shrimp to large predators like tuna, seabirds, and whales.

7) Seep mega-sites: COMARGE (http://www.coml.org/descrip/c-margins.htm) and ChEss scientists discover more lively communities flourishing off cold gases such as methane seeping out of the sea floor. Around New Zealand, they map the “Builder’s Pencil” site covering about 180,000 square meters, among Earth’s largest known seep sites. Sensitive to human activities despite their depth, the communities keep revealing unique features. Finding both potential new species and scars from deep-water trawls by fishing vessels on the scientific surveys suggests the urgency for further conservation of these fragile habitats.

8) Philippine firsts: In the first deep-sea work in the area, COMARGE researchers sample to a depth of 2,300 meters, collecting about 300 fish and 400 mollusc species for barcoding. Some 320 decapod crustaceans are photographed, displaying their beauty and aiding future identification of many unique and subtly distinct specimens.

In 2008, COMARGE investigators return to explore the Philippine margin of the South China Sea, between 100 and 2,200 meters depth. Discoveries include the first Philippine record of the deep-water stony coral Lophelia pertusa, the first living specimen of Acharax bartschi (a large bivalve living in symbiosis with bacteria), rare deep-water snails living on a dog’s skull that had washed out to sea, and a likely new species of shrimp belonging to a group only known from hydrothermal vents. The trawl also collected many plastic shopping bags.

9) Potential new marine protected area, Africa: While largely unexplored, the rich Western Indian Ocean, including the Mozambique channel, suffers destructive fishing practices, such as use of dynamite. Census-affiliated explorers with the Sub-Sahara African Committee chart a proposed marine protected area off Tanga, Tanzania. Using SCUBA and remotely operated vehicles, Tanzanian scientists and students join international researchers to survey life along transects that could be periodically revisited, collecting samples for identification and barcoding.

10) Life in coldest, saltiest seawater: ArcOD (http://www.coml.org/descrip/aobio.htm) researchers studying life in the Arctic find temperatures of –25°C in sea ice channels where brine is more than six times saltier than regular sea water. Representing the coldest conditions in the global ocean, researchers find sea ice algae, such as diatoms, and flagellates thriving in concentrations of thousands of individuals per liter.

11) 100 new species and records near Hawaii: CReefs (http://www.coml.org/descrip/c-reefs.htm) experts census biodiversity in the French Frigate Shoals, the world’s largest, fully protected marine area in the Northwestern Hawaiian Islands. Using a variety of new and proven methods over a diverse range of habitats, the team logs more than 100 species and new records.

12) Carpet of bugs: COMARGE researchers describe a new species of amphipod, Ampelisca mississippiana, inhabiting the head of the Mississippi Canyon about 460 meters deep in the Gulf of Mexico. These small crustaceans (less than 6 millimeters in length) and living in tubes, carpet the seabed in densities up to 12,000 individuals per square meter. Based on its abundance and the stabilizing effects this “carpet of bugs” has on sediments, researchers believe this amphipod may have great ecological importance.

13) Deepest comb jelly: CMarZ (http://www.coml.org/descrip/cmarz.htm) explorers find a potential new species of comb jelly, or ctenophore, at the record depth of 7,217meters in the Ryukyu Trench near Japan – the deepest ever recorded siting of this unique species, that flies like a kite on the end of two long “strings” attached to the bottom. The discovery raises questions about the availability of food resources at such depths, which had not been thought capable of supporting predators like this one.

14) Evolutionary mollusk: In the Southern Ocean, CAML (http://www.coml.org/descrip/caml.htm) researchers find many potential new species including sea cucumbers, sponges and komokiaceans – little known protozoa living in the depths of the ocean resemble the organisms that form chalk. They also collect a rare mollusk, named Laevipilina antarctica, believed to play a role in how segmentation evolved in marine invertebrates.

15) Arctic jellies galore: In the Canada Basin of the Arctic Ocean, ArcOD researchers find several new species and more than 50 taxonomic categories of gelatinous zooplankton. Almost two-thirds are medusae, one-fifth siphonophores, and one-tenth larvaceans. The first new species formally described from the expedition was named Sigambra healyae, in honor of the research vessel, the U.S. Coast Guard Cutter Healy.

16) 85 new zooplankton species: CMarZ scientists discover at least 85 new species of zooplankton, small drifting and swimming marine animals. Four genera and one family were officially deemed new to science, with many more expected to follow. In the Atlantic Ocean from Germany to South Africa, scientists collect zooplankton in a range from the surface to below 5,000 meters. Taxonomic experts and geneticists identify and barcode the DNA from hundreds of species. As expected, several new species of small crustaceans called ostracods or seed shrimp and other groups are found.

17) Antarctica’s big amphipod: CAML scientists exploring a 10,000 kilometer portion of the Antarctic Weddell Sea made suddenly accessible by the collapse of the Larsen A and B ice shelves sample an estimated 1,000 species. Of these, four presumed new species of cnidarians (organisms related to coral, jelly fish and sea anemones) are found, as well as 15 potentially new amphipod (shrimp-like) species, including one of Antarctica’s biggest-ever amphipod crustaceans, nearly 10 centimeters long.

18) Spectacular species in Celebes Sea: Zooplankton researchers with CMarZ travel to a biodiversity hot spot in the Celebes Sea in the southern Philippines, uncovering unexpected richness and diversity of marine life from the surface to the almost totally unexplored deep waters. Divers collect a remarkable variety of fragile and beautiful gelatinous species, while video cameras and collect images and organisms from depths beyond the divers' reach.

19) Surprising species richness: Recent advances in technology are opening up remote frontiers – deep-sea canyons. COMARGE researchers aboard the RRS James Cook off Portugal find that species richness was almost double in the more active Nazaré Canyon than in Lisbon Canyon. This is despite Lisbon Canyon receiving a substantial supply of river-borne organic matter that would foster large populations of filter-feeding organisms.

20) 11,130 known species in South African waters: Experts with the Census’ Sub-Sahara African Committee estimate 6,000 more species, primarily smaller marine animals, are yet to be discovered in South African waters, which are already known to feature some 11,130 species. A new shrimp (Hippolyte) and the first record of the enigmatic group Myzostomida from the region are discovered in False Bay, the most sampled site on the African coast.

21) 870+ squat lobster species: COMARGE scientists list 870 known species of squat lobsters and create an electronic library of relevant literature. Squat lobsters are colorful decapod crustaceans found in all oceans, at all depths, and in all marine habitats, but are especially abundant on continental margins.

22) Antarctic expressway: In the Southern Ocean, Census CAML explorers find evidence that deep sea octopuses ride the “Antarctic thermohaline expressway.” The northbound expressway is a mass of sea water with a high salt density caused by the ice that forms at the surface around the Antarctic, the water cascading like cream.

They find as well that sea birds feed on Antarctic zooplankton when the tiny organisms aggregate at a thermal front.

23) Animals in new places: ArcOD explorers make the first record of many marine animals in many areas of the Canada Basin. These include abundant and diverse ctenophore (comb jellies) under Arctic pack ice and a dense bed of sea cucumbers in what might be a pockmark. They also record more squid than ever before in the Arctic deep sea, and document the importance of sea ice ridges for marine life in the region.

24) White Shark Café: Satellite tagging by TOPP reveals a previously unknown behavior of white sharks (http://www.eol.org/taxa/17143484), travelling long distances each winter to concentrate in the Pacific for up to six months. During these months, both males and females make frequent, repetitive dives to depths of 300 meters, which researchers theorize may be significant in either feeding or reproduction.

25) Migration pathway: MAR-ECO researchers suggest the Mid-Atlantic Ridge may serve as an important pathway in colonization of North Atlantic continental slopes. Before their expeditions, scientists thought skates and rays, for example, migrated through the Mid-Atlantic Ridge, rather than taking up residence there.

26) New species in familiar waters: Systematically exploring two islands on the Great Barrier Reef and a reef off northwestern Australia, CReefs researchers find hundreds of new kinds of animals in waters were long familiar to divers. They also conduct the first scientific inventory of spectacular soft corals, named octocorals for the eight tentacles that fringe each polyp.

27) Australian expedition: One species in three new to science: The first results from the COMARGE “Voyages of Discovery” expeditions to the deep continental shelf and slope in Australia’s southwest region show 524 species of Decapoda—crabs, shrimps, prawns, lobsters, and the like. Some 33 percent of all species encountered are suspected to be new species, and 25 percent are new records in the region, eight percent are new records for Australia.

28) Sponge garden: COMARGE and ChEss researchers examining cold seeps in the Mediterranean Sea using remotely operated vehicles find surprisingly abundant marine life, including a garden of sponges around a brine lake. The sponge itself, likely Rhizaxinella pyrifera, harbours a multitude of small worms.

29) Behemoth bacteria: A diverse set of giant, filamentous, multi-cellular marine bacteria is discovered by ICOMM (http://www.coml.org/descrip/icomm.htm) researchers in the eastern South Pacific. These bacteria may be “living fossils” that developed in the earliest ocean when oxygen was either absent or much diminished, living on the toxic gas hydrogen sulfide. Scientists hypothesize that communities of bacteria may hold potential for bioremediation of organically polluted bottoms and, because of their ability to survive in anoxic conditions, may be an important clue in the search for extraterrestrial life.

30) Colossal sea stars: CAML expeditions to the Southern Ocean find frequent examples of gigantism common in Antarctic waters. The researchers collect huge scaly worms, giant crustaceans, starfish and sea spiders as big as dinner plates.

31) Largest mollusk in class: A giant aplacophoran mollusk, Chaetoderma felderi, is collected in deep waters off Louisiana by GoMex, a Census-affiliated project working in the Gulf of Mexico. Measuring over 407 mm in length and 10 mm in diameter, about the size of a AAA battery, it is more than twice the length and three times the diameter of the next largest known mollusk in the subclass.

32) Gigantic oysters: With the assistance of a remotely operated vehicle, COMARGE explorers find dense communities of giant oysters 20 cm (eight inches) long at a depth of 700 m on the La Chapelle continental slope. Genetic studies will confirm if this is a new species.

33) Barcoding zooplankton: An international CMarZ team from 25 cooperating projects is analyzing data from roughly 6,000 historical samples to help create a catalog of described species diversity and distribution. DNA barcodes will identify approximately 7,000 known species of zooplankton in 15 phyla. This growing database will help scientists identify specimens, describe their geographic distributions, and recognize when a species is in fact new. Scientists envision a day soon when quick, automated sample barcoding analysis will be a reality.

34) Following fishers to find vents: Stymied in their search for active methane seeps in the Chilean margin, COMARGE scientists take a novel approach: follow the fishers. They launch their search in known fishing grounds of the Patagonian toothfish (Dissostichus eleginoides), suspecting that these fish congregate near methane seeps. Their hunch proves correct: Most fishing grounds were associated with hard grounds, with some made of carbonates associated with methane seepages.

35) Coral reef colonization: To learn what new creatures colonize coral reefs, CReefs scientists develop and test Autonomous Reef Monitoring Structures (ARMS), to be colonized by fish and other creatures that inhabit coral reefs. The structures mimic the “nooks and crannies” of a natural reef. With this information, marine scientists can better understand the health of reefs and policy makers can develop scientifically-based management strategies.

36) Mapping microbes: To identify marine microbes and survey their distribution around the globe, ICoMM launches 40 separate projects using the same DNA sequencing technology, “454 tag-pyrosequencing.” The efficient identification by a standardized method allows scientists to inventory areas as diverse as polar biodiversity hotspots, coastal microbial mats, and sediments in tropical coral reefs. They can then create unprecedented global maps of the tiniest life in the ocean.

37) Arctic robots: Two new underwater robots give ChEss scientists a bird’s eye view of what lives on Gakkel Ridge in the Arctic Ocean. These exploration vehicles carry cameras and sophisticated arrays of instruments used by scientists to discover a new underwater volcanic chain covered by extensive microbial mats. Because the deep Arctic ridges are isolated from other ocean basins, the investigation of Gakkel Ridge provides clues about the evolution of fauna around underwater vents in isolated habitats.

38) Nearshore research expands worldwide: NaGISA expands nearshore research within the Caribbean, South America, and around the Indian Ocean through regional workshops aimed at standardizing protocols. Scientists use these protocols in monitoring and educational program to assess environmental impacts and to engage local communities in the process.

39) A highly detailed look at biodiversity in a well-documented bay: A unique collaboration of U.S. and Canadian GoMA (http://www.coml.org/descrip/gom.htm) researchers enhances knowledge of changing marine eco-systems by studying the nearshore zone of Cobscook Bay, Maine, from both historical and present-day perspectives. One of the most diverse coastal ecosystem on the North American east coast north of the tropics, this estuary features many different habitats, a tidal range of over eight  meters, two centuries of historical records dating back to 1842, and more than 800 species identified to date.

40) Engaging the public: NaGISA scientists studying the nearshore environment of the world ocean are present on six continents. Science education programs and training workshops aim to incorporate research protocols, which makes data gathered in the coastal environment comparable from place to place. The nearshore investigations engage the public in ocean and coastal issues and inspire the next generation of marine scientists.

41) International study of plankton bloom: In the Southern Ocean, collaborating CeDAMar (http://www.coml.org/descrip/cedamar.htm) researchers follow a plankton bloom from its onset until it changes to marine snow and finally sinks to the deep-sea floor. The scientists then examine the influence of the snow of fallen plankton on marine life on the floor itself. It is the first such collaboration undertaken since the Galathea expedition in the early 1950’s. In spite of bad weather and complicated logistics, the collaboration produces a trove of data.

42) Leading research for International Polar Year: Census projects play a key role in the International Polar Year 2007-2009. In the Arctic, the Census leads the marine biodiversity cluster of 13 projects from eight countries on more than 20 expeditions. They observe how mammals use diverse polar habitats, inventory life in a fjord, and explore seeps, pockmarks, and mud volcanoes on remote ocean floors. In the Southern Ocean, the Census coordinates the science on 10 major expeditions by vessels from nine different countries, the results reported live via the Internet. The Census also initiates a collaborative program focusing on Antarctic marine life in seven South American countries.

43) Race to protect sea turtles: The Great Turtle Race, an international race developed by TOPP to save a 100-million-year-old species from extinction moved to China in 2008. A Mandarin language version of an interactive webpage tracks the migration of endangered leatherback turtles, bringing the race to approximately 100 million Chinese citizens. Donations go to protection of leatherback turtle nesting areas in Indonesia, and raise awareness of the turtles plight.

44) Leatherback conservation: For more than 12,095 satellite-tracking days over three years, TOPP scientists track leatherback turtles and compile the largest, multi-year migration record ever. The data reveals that ocean currents shaped the migration corridor and turtle dispersal in the South Pacific.

45) Hydrothermal vents and seabed mining: ChEss scientists orchestrate a joint scientific and policy meeting for the spring of 2009 to discuss protection of the vent sites from the potential growth of deep sea mining. The meeting’s goal: set priorities for future research and balance the conservation of critical vent sites versus the value of ores.

46) Focusing fishery management: MAR-ECO research along the Mid-Atlantic Ridge strives to fill information gaps about the distribution and abundance of certain species of grenadier (http://www.eol.org/taxa/17063155), distant relatives of codfish in the North Atlantic. Amid the uncertainty, regional managers take precautionary measures to protect grenadier stocks and their habitats.

47) CSI in the sea: DNA barcoding shark fins: Demand for their fins and other organs impact global shark populations. The frequently inaccurate identification of sharks and rays confuses what fishermen are catching, what fins and organs markets are selling, and how populations are changing. Accordingly, researchers with the Marine Barcode of Life project (http://www.marinebarcoding.org/publications) develop DNA barcoding to identify species of sharks and their products, such as dried fins, essential to knowing how many sharks are being caught and to enforce prohibitions. (See also http://phe.rockefeller.edu/docs/pacificfishingsept2008.pdf)

48) Managing underwater mountains: CenSeam expeditions in the Southern Ocean and Antarctica expand knowledge of life on seamounts, providing a foundation for sustainable management of these ecosystems. Census researchers deliver a report to the United Nations General Assembly on the vulnerability of seamount corals to fishing and help develop guidelines for deep-sea fisheries.

49) Learning from the past: Rise and fall of tuna: Scouring fishery reports, fishing magazines, and other records, HMAP (http://www.coml.org/descrip/hmap.htm) researchers document the presence of bluefin tuna (http://www.eol.org/taxa/17050078) in northern European waters several decades before the onset of major fisheries in the early 1900s. After fishing increased and techniques became more powerful, the fishery collapsed in the mid-1960s. Documentation of the historical abundance of this especially popular seafood species, and its subsequent collapse, will be used to inform future decisions.

50) Assessing human impact: HMAP brings together a worldwide network of experts from multiple disciplines to figure out why populations of mollusc have declined. They report their work in a book, Early Human Impact on Megamolluscs (Oxford: Archaeopress).

51) High mortality for young salmon: Using acoustic tagging, POST (http://www.coml.org/descrip/post.htm) researchers track the progress of young Chinook salmon (http://www.eol.org/taxa/17154704) as they move from freshwater rivers in the Canadian and US northwest out to the ocean and eventually to the Alaska coast. The observations suggest that in just a few weeks, 40 percent of the tracked salmon perished in the ocean.

52) Sturgeon playground: POST researchers discover green sturgeon congregate at a “playground” off Vancouver Island before moving on to Alaska for the winter, contrary to scientists’ expectations. The reason for their layover is unknown, but it makes them susceptible to potential over-exploitation.

53) Conserving life in open ocean: MAR-ECO documentation of the quantity and patterns of diversity on the mid-Atlantic Ridge summit at 3,500 meters helps international management organizations protect habitats and assure sustainable resource use. Continued work by Census scientists and a variety of partners creates a better basis for conservation of marine life in the immense areas of the oceans that lie beyond national jurisdiction.

54) Tuna and Billfish distribution: FMAP (http://www.coml.org/descrip/fmap.htm) researchers investigate the global distribution patterns of two highly migratory predators, tuna and billfish, and relate the information to the temperature tolerances of these species, work that may help anticipate the effects of ocean warming on biodiversity.

55) OBIS reaches 16 million records: Census experts creating the Ocean Biogeographic Information System (http://www.coml.org/descrip/obis.htm), log 16 million biological records, with 17 million expected by year’s end, received from nodes around the world. Collaboration with the Encyclopedia of Life, among others, expedites information sharing, creating an integrated system containing geographical, biographical, evolutionary, and genetic information, as well as images.

56) Counting all creatures in the Gulf: Scientists complete a comprehensive inventory of all marine life in the Gulf of Mexico. Published in a 79-chapter book written by 140 authors from 15 countries, the inventory shows 15,625 species from 40 different phyla in the Gulf. A second phase of the project currently underway will make the information available in a searchable online database.

57) Listing all species, eliminating aliases: The list of known marine species surpasses 120,000, placing the Census halfway toward its goal of cataloging the estimated 230,000 known species by 2010. The Census-affiliated World Register of Marine Species (WoRMS) identifies more than 56,000 aliases for ocean species, with one species, the “breadcrumb sponge,” alone having 56 scientific names.

58) 4,000 Marine Fish May Await Discovery: Employing a novel approach to count quantify global fish species, FMAP researchers estimate that almost 16,000 species of marine fish are recorded in publicly accessible databases. They suggest another 4,000 fish species await discovery and description, many of them in the tropics.


WEATHER NOTE


Ike's surge means slow coastline recovery

ANGLETON — Hurricane Ike's storm surge was so widespread, so high and so violent that it will take much longer than usual for the Texas coastline to recover, the director of coastal resources for the Texas General Land Office said.

Ike washed millions of tons of beach sand into coastal marshes so far out into the Gulf that some beaches will be changed forever, Eddie Fisher said at a town hall meeting at the Brazoria County Courthouse.

"We're going to have to do a lot of beach replenishment projects," Fisher said.

He said about 100 homes on Galveston Island are now on the surf side of the vegetation line — the line used to denote public beaches.

So much vegetation has been stripped away that the Land Office plans to use a line of elevation 4.5 feet above mean sea level to establish the new beach line until vegetation returns, he said.

The first maps of the 4.5-foot line should soon be available on the Land Office Web site at www.glo.state.tx.us, he said. Maps of the city of Galveston will be done first, then Bolivar and Brazoria County, he said.

Mapping Bolivar Peninsula is especially difficult, he said, "because there is so much total destruction. We lost all our benchmarks."

Coastal residents did get some good news.

Brazoria County Commissioner Dude Payne said the county has approved $1.9 million to build a 16-foot-wide crushed concrete temporary road to replace parts of County Road 257, also known as the Blue Water Highway, between Surfside Beach and San Luis Pass.

He said a more permanent roadway will cost $50 million to $100 million because sand dunes or rock revetments also will have to be constructed to protect it from future storms.

State Rep. Dennis Bonnen, R-Angleton, said a legislative subcommittee will soon start holding meetings on how to help the coast recover from Ike.

Deryl Tumlinson, of CenterPoint Energy, said work teams are rebuilding the power line from Surfside Beach to subdivisions at San Luis Pass and plan to have power to those areas restored by Nov. 10.

MARITIME NOTE

Inquest recommendations accepted by locals

Direction of Dept. of Transport a cause of concern for some


The owner of a marine contracting business is pleased with the jury's recommendations into the inquest of a 2004 boating accident.

A coroner's jury has recommended stricter licencing and safety requirements for the more than 50,000 small commercial vessels operating in Canadian waters.

The jury's recommendations were made last month after a four-day inquest into a boating accident at Payette Island, near Honey Harbour, on Dec. 10, 2004, in which 39-year-old Eugene Bovingdon drowned after the work-boat he was aboard capsized. Three other men aboard the vessel reached shore safely.

"Almost four years ago we were saddened by the loss of employee Eugene Bovingdon," said Armin Grigaitis, owner of A and A Services and Marine Contracting Limited.

"All those feelings and emotions were rekindled for staff and family and we extend our heartfelt condolences to Eugene's family."

He said the business and its employees continue to work with the Ministry of Labour, Transport Canada, the Construction Safety Association and fellow colleagues in the marine construction industry to establish improved safety protocols for all workers who travel on the water.

"Our hope is Eugene's passing will induce more people in the industry to work with these same agencies," he said.

Although he is concerned that Transport Canada, in the last few years, has moved to a self-inspection program rather than expert inspection services for these types of vessels.

Grigaitis said his company will continue to diligently bring to the forefront the areas of concern for the marine construction industry.

Although not familiar with the accident, Michael Dubeau, co-owner of Midland Tours, said any recommendations that are going to better the safety of passengers and employees should be taken seriously.

"There should be no short cuts for safety."

He said with larger passenger vessels, the industry has gone through safety changes "as a result of things that have happened like the drowning of the students in Tobermory."

He said Transport Canada needs to be aware of the number of commercial vessels that are in the marketplace, and the ones that are registered and not registered.

"The biggest problem is the cutbacks," he said. "Transport Canada just doesn't have the personnel to be out in the marketplace to do the things that these recommendations are asking for."

Midland Tours features the Miss Midland 30,000 Islands Boat Cruises on Muskoka-Georgian Bay, Serendipity Princess Barrie Boat Cruises on Kempenfelt Bay, Casino Rama tour packages, and escorted motor coach day and overnight Tours.

The jury does not make any finding of legal responsibility and its recommendations are not legally binding.

RECOMMENDATIONS:

* The owners of small commercial vessels should form an association to communicate with Transport Canada, to communicate safety expectations and to expedite safety training.

* In water conditions of 15 degrees Celsius or below, a cold water immersion suit should be worn by all persons on a small commercial vessel up to 15 gross tonnes.

* Safety equipment should be standardized on all small commercial vessels under 15 gross tonnes.

* All vessels under 15 gross tonnes that have the potential to be used as cargo or passenger boats should be registered as small commercial vessels.

* Information pertinent to registering a small commercial vessel should be readily available from Transport Canada to the public through sites such as Service Canada outlets, selected marinas, and the marine policing units.

* Transport Canada should ensure that all registered small commercial vessel owners are provided with relevant safety information. This will include current regulations, acts, ship safety bulletins, contact numbers where owners might seek assistance, the Small Vessel Monitoring and Inspection Program, and the Small Commercial Vessel Safety Guide.

* Every small commercial vessel owner is required to license their vessel with Transport Canada and renew the licence every four years.

* A licence will not be granted unless and until the small commercial vessel passes an inspection by Transport Canada or authorized accredited marine personnel.

* All new small commercial vessels up to 15 gross tonnes need a conformity plate permanently attached to the transom. This plate would state a safe working load, maximum number of passengers, date of inspection, and expiry date within four years of inspection.

* No modification shall be made to a small commercial vessel up to 15 gross tonnes without prior authorization by Transport Canada. Upon completion of the modification, the vessel shall be inspected by Transport Canada or by authorized, accredited marine personnel.

* All small commercial vessels up to 15 gross tonnes in Canada are required to have liability insurance as stated in recommendation # 37 of the True North inquest.

* Owners of small commercial vessels up to 15 gross tonnes should pursue all available means to ascertain safety requirements and regulations pertaining to their particular vessels.

* Automatic or floating switch bilge pumps should be installed in every small commercial vessel up to 15 tonnes.

* Owners of small commercial vessels up to 15 gross tonnes and employees should be required to take The Small Vessel Operator Proficiency Course and The Marine Emergency Duties Course in order to educate themselves about water safety and emergency situations.

* During winter months, owners of small commercial vessels up to 15 gross tonnes and employees should obtain weather forecast updates throughout the day.

* There should be harsh penalties for non-compliance with occupational safety or marine safety laws or regulations.

* Amend the Canada Labour Code and encourage provincial labour jurisdictions to broaden the definition of "workplace" so that it will encompass transportation to and from a job site if that transportation involves travel on water, air or land where a Highway Safety Act does not apply.

* Every small commercial vessel up to 15 gross tonnes should be equipped with a VHF radio and the vessel's operator should file a sailing plan before the vessel's departure.

* Every small commercial vessel up to 15 gross tonnes should be equipped with an electronic position-indicating radio beacon (EPIRB).

* Transport Canada should develop partnerships with third parties (eg. accredited marine mechanics, marine architects, or marine surveyors) to inspect small commercial vessels up to 15 gross tonnes, with assistance and advice from Transport Canada inspectors.

12 of 20 Cruise Ships Cited for Pullution


According to a report from the Anchorage Daily News, an analysis by state regulators shows that more than half of the cruise ships that discharged wastewater regularly into Alaska waters received citations.

The analysis shows 45 tests on wastewater violated permit levels for pollutants. The most common violation was for ammonia, found in urine.



RS

Wednesday, November 12, 2008

Scientists find evidence of tsunamis on Indian Ocean shores long before 2004

Scientists find evidence of tsunamis on Indian Ocean shores long before 2004

A quarter-million people were killed when a tsunami inundated Indian Ocean coastlines the day after Christmas in 2004. Now scientists have found evidence that the event was not a first-time occurrence.

A team working on Phra Thong, a barrier island along the hard-hit west coast of Thailand, unearthed evidence of at least three previous major tsunamis in the preceding 2,800 years, the most recent from about 550 to 700 years ago. That team, led by Kruawun Jankaew of Chulalongkorn University in Thailand, included Brian Atwater, a University of Washington affiliate professor of Earth and space sciences and a U.S. Geological Survey geologist.

A second team found similar evidence of previous tsunamis during the last 1,200 years in Aceh, a province at the northern tip of the Indonesian island of Sumatra where more than half the deaths from the 2004 tsunami occurred.

Findings from both teams are published in the Oct. 30 edition of Nature.

Sparse knowledge of the region's tsunami history contributed to the loss of life in 2004, the scientists believe. Few people living along the coasts knew to heed the natural tsunami warnings, such as the strong shaking felt in Aceh and the rapid retreat of ocean water from the shoreline that was observed in Thailand.

But on an island just off the coast of Aceh most people safely fled to higher ground in 2004 because the island's oral history includes information about a devastating tsunami in 1907.

"A region's tsunami history can serve as a long-term warning system," Atwater said.

The research will reinforce the importance of tsunami education as an essential part of early warning, said Jankaew, the lead author.


"Many people in Southeast Asia, especially in Thailand, believe, or would like to believe, that it will never happen again," Jankaew said. "This will be a big step towards mitigating the losses from future tsunami events."

The team found evidence for previous tsunamis by digging pits and auguring holes at more than 150 sites on an island about 75 miles north of Phuket, a Thai tourist resort area ravaged by the 2004 tsunami. That tsunami was generated 300 miles to the west when the seafloor was warped during a magnitude 9.2 earthquake.

At 20 sites in marshes, the researchers found layers of white sand about 4 inches thick alternating with layers of black peaty soil. Witnesses confirmed that the top sand layer, just below the surface, was laid down by the 2004 tsunami, which ran 20 to 30 feet deep across much of the island.

Radiocarbon dating of bark fragments in soil below the second sand layer led the scientists to estimate that the most recent predecessor to the 2004 tsunami probably occurred between A.D. 1300 and 1450. They also noted signs of two earlier tsunamis during the last 2,500 to 2,800 years.

There are no known written records describing an Indian Ocean tsunami between A.D. 1300 and 1450, including the accounts of noted Islamic traveler Ibn Battuta and records of the great Ming Dynasty armadas of China, both of which visited the area at different times during that period. Atwater hopes the new geologic evidence might prompt historians to check other Asian documents from that era.

"This research demonstrates that tsunami geology, both recent and past tsunamis, can help extend the tsunami catalogues far beyond historical records," Jankaew said.

The new findings also carry lessons for the northwest coast of North America, where scientists estimate that many centuries typically elapse between catastrophic tsunamis generated by the Cascadia subduction zone.

"Like Aceh, Cascadia has a history of tsunamis that are both infrequent and catastrophic, and that originate during earthquakes that provide a natural tsunami warning," Atwater said. "This history calls for sustained efforts in tsunami education."

Note: This story has been adapted from a news release issued by University of Washington

WEATHER NOTE

Reburying the dead a grim task in Ike's wake

IN THE MARSH OF CAMERON PARISH, La. (AP) — Joe Johnson craned his neck from the airboat as it circled a patch of brown marsh grass. The runaway coffin was not where it was supposed to be.

Johnson pulled up to a pile of rocks, killed the motor and hopped out. After a few minutes of scouring along the tall, reedlike grass, he flagged down two fishermen.

"Can you possibly take me along the shoreline?" Johnson asked. "I'm looking for a casket."

Beyond the usual, dismal rebuilding, Hurricane Ike left another grim task when it struck last month: Its 13-foot storm surge washed an estimated 200 caskets out of their graves, ripping through most of Cameron Parish's 47 cemeteries and others in southwest Louisiana and coastal Texas. Some coffins floated miles into the marsh.

At Hollywood Cemetery in Orange, Texas, Ike unearthed about 100 caskets. Dozens more were disgorged in hard-hit Galveston.

Officials in coastal areas have long struggled with interring the dead, as caskets buried in low-lying areas are susceptible to being belched up by floodwaters. Some areas — most notably New Orleans — house the dead in above-ground crypts to keep them from drifting away in storms.

For many of the dead forced up by Ike, it wasn't their first disturbance. About 80 percent of the caskets in southwest Louisiana displaced by Ike were rousted by Hurricane Rita just three years earlier, said Zeb Johnson, the Calcasieu Parish deputy coroner who's headed casket recovery efforts for Rita and Ike.

Of the caskets ejected by Rita in September 2005, 335 were found and reburied, he said. Eighteen were never found.

"Our mother came out for Rita, and now she came out for Ike," said Debra Dyson, a commercial fisher whose house in Cameron was destroyed by Ike.

Dyson said coffins holding her brother-in-law and cousin also were heaved out by Rita. Ike was worse — the storm thrust out caskets containing her mother, brother-in-law, cousin, niece, three uncles and two aunts.

The one containing Dyson's mother floated to the same spot it came to rest after Rita, 22 miles from the cemetery. Only this time, it didn't take nine months to find it.

"It's hard to lose your home, but the first stop you make is that cemetery just to make sure they're still there, and it's heartbreaking when they're not," said Marilyn Dyson Elizondo, Dyson's sister who lives in Dayton, Texas.

Zeb Johnson helms a team of two employees, volunteer boat pilots and state prisoners to search hundreds of miles of marsh with loaned equipment and haul coffins back to shore. The work is backbreaking, with caskets weighed down by mud in swampy areas teeming with alligators and snakes and the stench of rotting marsh grass.

"It's a job that has to be done," said Joe Johnson, a funeral director and embalmer from Lake Charles who is not related to the deputy coroner.

Joe Johnson's half-hour ride with the fishermen didn't turn up the pink casket reported to the coroner's office, like so many other tips that don't pan out. An hour later, however, he returned with another coffin found in thick grass near a canal bank.

A hole was drilled into the silver metal container to drain out marsh muck and lighten the load for the airboat. Prisoners pulling the casket from the boat tipped it again to empty out more of the fetid water.

The coffin was trucked to the city coliseum in Lake Charles, where the Federal Emergency Management Agency was providing refrigerated trucks to hold caskets until reburial arrangements could be made.

"It's a slow process," Zeb Johnson said.

The Calcasieu Parish Coroner's Office is footing most of the search and recovery bill, which hasn't been tallied. But reburying the dead is estimated to cost as much as $100,000 on top of the recovery costs, with much of the money needed for new caskets and vaults. Zeb Johnson wasn't sure who'll cover that price tag, so he wasn't sure when reburial could begin.

More than 140 coffins had been found by Wednesday, and about 20 others that didn't stray far from their burial sites were quickly reburied. Zeb Johnson doesn't expect to find all of the two dozen or more that remain missing.

"The first day we found caskets that had floated 30 miles from their cemeteries," he said. "You just have caskets floating out in the marsh. At least seven of these caskets ended up in Texas, kind of like boats, they just got out in the currents from the high waters and carried them to Texas."

The identification work in many instances is easier this time around. Bodies found after Rita were tagged with special markers, as were the silver metal coffins in which they were reburied. The coffins include a scroll with the deceased's name, where they were buried and other information.

A few families are considering reburials on higher ground. Cameron Parish's government has proposed requiring deeper burials.

Elizondo, whose family awaits word on the missing Dyson caskets, said her brother was buried in January in a deeper vault than those that housed her missing relatives. Ike didn't disturb her brother, so Elizondo wants to rebury her mother the same way, though it is more expensive.

"It's worth it. That way we have the peace of mind that mom won't be gone again," Elizondo said. "We've even offered to do the backhoe ourselves. We just don't want her coming back up again."

MARITIME NOTE

Napoli bill put at staggering £120m

THE grounding of the MSC Napoli off the Westcountry coast is the second most expensive shipping incident ever, it has emerged.

Insurers of the 62,000-tonne container ship, beached off East Devon in January 2007, have estimated the total bill for the wreck at £120 million.

It means the clean-up, salvage, vessel and cargo costs from the Napoli are second only to the Exxon Valdez – the tanker which spilt 10.8 million gallons of crude oil into the sea at Prince William Sound, Alaska, in 1989.

One of the biggest environmental disasters to occur at sea, its costs have run into hundreds of millions of pounds. News of the vast bill emerged as the Maritime and Coastguard Agency released a report into the grounding, making 11 recommendations.

Charles Hattersley, a Plymouth- based marine law expert, said the huge costs were "understandable" given the nature of the incident. But he said the scale, and cost, of the incident had not been matched by the Government's response.

"In my view, the Government should have instigated its own public inquiry into what happened," said Mr Hattersley, a partner at Ashfords solicitors. "Instead, Devon County Council has had to step up to the plate."

The cost of the Napoli grounding was revealed by the London Steam-Ship Owners' Mutual Insurance Association Limited, otherwise known as the P&I (Protection and Indemnity) Club. It is managed by London-based A Bilbrough and Company Limited.

In its annual report, chief executive Paul Hinton confirmed the Napoli's £120 million estimated bill was the "second most expensive claim ever".

He said the beaching of the vessel had avoided "a potentially very grave environmental disaster". He described the aftermath as "an enormous challenge in technical, regulatory and legal terms".

Mr Hinton added: "The salvage and removal of the wreck of the ship and her containers, as well as the disposal of cargo within the containers, has been a unique experience in a number of respects, but importantly, it is the first occasion on which a large container ship has foundered in a recoverable condition off the coast of a European state.

"Other container ships have been salvaged following fire or explosion (resulting in the loss of a relatively small proportion of their cargo) or have sunk in deep water (with the total loss of ship and cargo). "The MSC Napoli represents the first occasion when almost the totality of a ship's container cargo has been brought ashore in both sound and extensively wetted condition, for forwarding and disposal.

"This huge undertaking has also taken place under the watchful eye of one of the most robust environmental regulatory regimes in the world and every aspect of the waste cargo handling and disposal operation, involving the disposal of some 30,000 tonnes of cargo, has been scrutinised by the Environment Agency."

He said the total cost of recovering the cargo and removing the ship had escalated to some £53 million. Yesterday, the MCA's 103-page report into the incident was submitted to the Devon County Council-led inquiry into the grounding.

It concedes that lessons can be learned to improve communication between organisations and streamlining the jurisdiction between land and sea.

The report highlights 11 recommendations which include improving communications between salvagers and land-based response organisations, and educating other agencies on marine emergency procedures.

It says the next Marine National Contingency Plan should assess who is best-placed to take responsibility for protecting and cleaning the shoreline, and also how various response centres could be merged to offer more effective communication and partnerships.

But the professionalism of those involved in the operations at sea meant the risk of years of oil pollution along the coasts of Devon was averted.

The report summarises the MCA's activities from January 18 last year when the Napoli, bound for South Africa, "suffered a catastrophic hull failure" when she was 50 miles south of Cornwall's Lizard peninsula, and the 26-strong crew was rescued after taking to life-rafts.

It addresses the controversial issue of why the Napoli was towed to British waters instead of French, when its position was between the two. "The conclusion was that the least environmentally risky option was to tow the vessel to a place of refuge in UK waters," it says.

The Secretary of State's Representative for Maritime Salvage and Intervention, Robin Middleton, decided the ship was in danger of breaking up and polluting the English Channel and should be towed to Portland. But, during the operation, the weather deteriorated and the salvors and Mr Middleton decided to beach her in Lyme Bay to minimise the pollution threat.

The report says the only option was to ground the ship on shallow waters to avoid "almost certain" break-up. The Napoli had 3,664 tonnes of fuel oil and marine diesel on board.

"The spilled oil would have escaped and found its way on to many beaches, possibly on both sides of the Channel, for many years," says the report.

The report accepts that the "understandable" confusion over the legislation governing salvage had been exploited by salvagers who descended on Branscombe's beaches after 50 containers washed ashore.

RS