... In Search of Severe Weather: Innovation: Tsunami Detection by GPS

Friday, March 7, 2008

Innovation: Tsunami Detection by GPS

Innovation: Tsunami Detection by GPS

How Ionospheric Observations Might Improve the Global Warning System

INNOVATION INSIGHTS with Richard Langley

THE TSUNAMI generated by the December 26, 2004, earthquake just off the coast of the Indonesian island of Sumatra killed over 200,000 people. It was one of the worst natural disasters in recorded history. But it might have been largely averted if an adequate warning system had been in place.

A tsunami is generated when a large oceanic earthquake causes a rapid displacement of the ocean floor. The resulting ocean oscillations or waves, while only on the order of a few centimeters to tens of centimeters in the open ocean, can grow to be many meters even tens of meters when they reach shallow coastal areas. The speed of propagation of tsunami waves is slow enough, at about 600 to 700 kilometers per hour, that if they can be detected in the open ocean, there would be enough time to warn coastal communities of the approaching waves, giving people time to flee to higher ground.

Seismic instruments and models are used to predict a possible tsunami following an earthquake and ocean buoys and pressure sensors on the ocean bottom are used to detect the passage of tsunami waves. But globally, the density of such instrumentation is quite low and, coupled with the time lag needed to process the data to confirm a tsunami, an effective global tsunami warning system is not yet in place.

However, recent investigations have demonstrated that GPS might be a very effective tool for improving the warning system. This can be done, for example, through rapid determination of earthquake magnitude using data from existing GPS networks. And, incredible as it might seem, another approach is to use the GPS data to look for the tsunami signature in the ionosphere: the small displacement of the ocean surface displaces the atmosphere and makes it all the way to the ionosphere, causing measurable changes in ionospheric electron density.

In this month's column, we look in detail at how a tsunami can affect the ionosphere and how GPS measurements of the effect might be used to improve the global tsunami warning system.

"Innovation" is a regular column that features discussions about recent advances in GPS technology and its applications as well as the fundamentals of GPS positioning. The column is coordinated by Richard Langley of the Department of Geodesy and Geomatics Engineering at the University of New Brunswick, who welcomes your comments and topic ideas. To contact him, see the "Contributing Editors".

The December 26, 2004 earthquake-generated Sumatra tsunami caused enormous losses in life and property, even in locations relatively far away from the epicentral area. The losses would likely have never been so massive had an effective worldwide tsunami warning system been in place. A tsunami travels relatively slowly and it takes several hours for one to cross the Indian Ocean, for example. So a warning system should be able to detect a tsunami and provide an alert to coastal areas in its path. Among the strengths of a tsunami early-warning system would be its capability to provide an estimate of the magnitude and location of an earthquake. It should also confirm the amplitude of any associated tsunami, due to massive displacement of the ocean bottom, before it reaches populated areas. In the aftermath of the Sumatra tsunami, an important effort is underway to interconnect seismic networks and to provide early alarms quantifying the level of tsunami risk within 15 minutes of an earthquake. (Continued)

WEATHER NOTES

Second Spring Flood Outlook Released March 7

The second 2008 Spring Flood Outlook was released March 7, 2008 and indicates a high flood potential for streams across northern Illinois and northwest Indiana this Spring. The area of greatest concern for snowmelt flooding includes the Rock, Pecatonica, and upper Fox rivers in northern Illinois. Moderate to major flooding is possible along portions of the Rock and Pecatonica rivers. In addition, due to the already saturated conditions, flooding will continue on the Kankakee River in northwest Indiana.

The complete report can be viewed here.

We also urge those with river interests to view our Advanced Hydrologic Prediction Service (AHPS) web pages, for the latest river stages and river forecasts and probabilistic flood outlook information.

The amount or severity of spring flooding depends on the following factors:

Current snow depth
Liquid equivalent of the snow
Current river levels and streamflow
Melting rate (how fast the snow melts)
Future precipitation
Soil moisture and frost depth
Ice jams (can lead to flash flooding)

Additional Spring Flood Outlook information is available from the North Central River Forecast Center.

The next scheduled spring flood outlook with be issued on Friday, March 28th.

Bad weather brings delays and destruction

By Ian Johnston

Last Updated: 12:31am GMT 02/03/2008

Tens of thousands of rail travellers face continuing delays today after gales of up to 84mph in the early hours of yesterday led to a major route becoming blocked.

Containers were blown off freight trains, badly damaging the West Coast Mainline in two locations.

The storm also caused the destruction of two new multi-million pound cranes at the port of Felixstowe when a Chinese container ship, which had just delivered them, broke its moorings at about 1.30am yesterday morning.

A 67-year-old woman who was crushed by a falling tree near Cleveland on Friday was in a critical condition in hospital yesterday while buildings near the epicentre of Wednesday's earthquake in Lincolnshire were damaged again. (Continued)

Tuesday total: 4 tornadoes
By STEVE LYTTLE

The National Weather Service offices across the Carolinas said surveys show four tornadoes touched down Tuesday during severe weather which affected the Southeast.

All of the tornadoes were relatively weak, and no injuries were reported.

Two of the twisters touched down not far from the Charlotte area.

The National Weather Service in Columbia says a tornado reached the ground about 4:40 p.m. Tuesday 4 miles east-northeast of Great Falls, about 55 miles south of Charlotte. The storm was estimated to have an F0 intensity (the weakest on the Fujita scale, which ranks tornado intensity from F0 to F5). Meteorologists say the Great Falls tornado was on the ground for about a mile and was 40 yards wide. It damaged trees in its path.

The same storm was responsible for a tornado warning issued a short time later in Lancaster County, but there is no confirmation that the twister touched down there.

A second Charlotte-area tornado was in Davie County, about 30 miles east of Statesville. The National Weather Service office in Greer, S.C., said this storm, also an F0, touched down in the Cornatzer community and was on the ground for about 2/3 of a mile. It was about 25 yards wide and struck about 6 p.m.

The Davie County tornado had top winds of 70 to 80 mph and damaged a mobile home and several other buildings.

The other tornadoes were in Prosperity, S.C., and in Alamance County of North Carolina.

The Prosperity storm struck about 4:20 p.m. and was an F1. It also damaged trees. Prosperity is near Newberry, S.C., northwest of Columbia.

The Alamance County tornado struck in the early evening hours and was an F0, about 100 yards wide. This storm was on the ground for 5 miles and damaged a number of buildings in Alamance and Caswell counties, near the North Carolina-Virginia line.

March 2-8 is Severe Weather Preparedness Week

Tornadoes can strike at anytime, day or night, but can be especially deadly in the middle of the night when many people are asleep. The Illinois Emergency Management Agency (IEMA) and the National Weather Service (NWS) are reminding people that weather radios save lives by providing round-the-clock alerts of imminent dangers (read press release).

The Illinois Emergency Management Agency (IEMA) has developed a Severe Weather Preparedness document with tips on staying safe during the severe weather months.

Senate hearing on NOAA budget

On March 13, the Subcommittee on Oceans, Atmosphere, Fisheries, and Coast Guard of the Senate Committee on Commerce, Science & Transportation will conduct an oversight hearing on the National Oceanic and Atmospheric Administration Budget. (3/5/08).

Freague Waves on Global Warning Consensus, what consensus?

MARITIME NOTES
Coast Guard helps save 72-foot tanker that was taking on water

March 6, 2008

PORTLAND, Maine --A tanker that began taking on water 35 miles off the coast of Maine has been saved from sinking with help from the Coast Guard. The 72-foot island tanker William McLoon is currently in Portland, where it towed by the Coast Guard for repairs.

The drama unfolded Tuesday night when the tanker's three-man crew reported a flooded engine room.

Chief Warrant Officer Curtis Barthel says there was about three feet of water in the engine room and water on the deck, and the crew didn't know where it was coming from.

Three Coast Guard boat crews and two air crews responded. The Coast Guard delivered a water pump and a rescue crew assisted in keeping the tanker afloat.

The Coast Guard says the tanker was headed to Florida when it encountered problems. It arrived in Portland on Wednesday for inspection and repairs.

Russian ship Pallada enters Panama Canal on round world trip

27/02/2008 14:11 VLADIVOSTOK, February 27 (RIA Novosti) -

The Russian sailing ship Pallada entered the Panama Canal on Wednesday as part of its journey around the world, a spokesman for the vessel's owner said on Wednesday.

"The ship will sail from the Pacific to the Atlantic in around 14 hours," he said, referring to the trip through the Panama Canal.

The frigate of the Far Eastern State Technical Fishing University departed from Vladivostok, Russia's largest port on the Pacific, on November 2, 2007.

The trip is dedicated to the 190th anniversary of the world-round trip performed by Russian ships led by Faddei Bellinsgauzen and Mikhail Lazarev, as well as 50 years of Russian research in Antarctica.

The spokesman also said the vessel would later drop anchor in the Caribbean to get drinking water and food. The ship is then due to arrive in Caracas, Venezuela on March 4. It is then scheduled to leave for Cuba two days later.

The ship, with 121 marine cadets on board, is to cover 32,800 nautical miles and visit 22 countries in 9 months.

The three-mast Pallada is listed in the Guinness Book of Records as the fastest sailing vessel in the world, with a speed exceeding 18 knots.

The sailing ship, the winner of many international festivals and races, has performed over 100 international trips over 13 years. It has also been visited by many famous people, including Jackie Chan and Arnold Schwarzenegger.

GAO Evaluates Coast Guard's Shift to Homeland Security GAO | Download Full Report

The Deepwater Program is intended to replace or modernize 15 major classes of Coast Guard assets–including vessels, aircraft, and communications systems. At the program's start, the Coast Guard chose to use a system integrator, Integrated Coast Guard Systems, to design, build, deploy, and support Deepwater in a system-of-systems approach. In a series of reports, we have noted the risks inherent in this approach.

With the Deepwater program under way, the Coast Guard's priorities and focus shifted after September 11 toward homeland security missions, such as protecting the nation's ports and waterways. The 2002 Maritime Transportation Security Act and the 2006 SAFE Port Act required a wide range of security improvements. GAO is monitoring the acquisition of Deepwater and the Coast Guard's ability to carry out its numerous missions. This testimony addresses: