Thursday, February 09, 2012

Philippines tsunami alert


Monday, Feb. 06, 2012

6.8 Earthquake Shakes Central Philippines

(MANILA, Philippines) — A strong earthquake struck the central Philippines on Monday, killing a child, destroying buildings, shattering windows and triggering a local tsunami alert that sent residents fleeing.
The 6.8-magnitude quake hit in a narrow strait just off Negros Island. The Philippine Institute of Volcanology and Seismology issued the tsunami alert for central islands, saying the quake could trigger a 3-foot (1-meter) wave along the island's eastern coast as well as west of the country's second-largest city, Cebu. (See photos of earthquake that rocked Japan.)
The Pacific Tsunami Warning Center did not issue a wider regional warning.
The epicenter was closest to Tayasan, a coastal town of about 32,000 people flanked by mountains in Negros Oriental province. A child there died when a concrete fence of a house collapsed, said Benito Ramos, head of the Office of Civil Defense.
"So far one dead, but we could not yet account for the damage to buildings," Tayasan police officer Alfred Vicente Silvosa told The Associated Press by phone. He said there were still aftershocks "so we are outside, at the town plaza. We cannot inspect buildings yet because it's dangerous."
"I felt the building shaking, so I rushed out of the building. Our computers, shelves, plates, the cupboards, water dispenser all fell," he said.
A three-story office building collapsed in La Libertad town in Negros Oriental but there were no immediate reports of casualties. Occupants of the building ran out.
Five bamboo and wooden cottages were washed out from a La Libertad beach resort by huge waves, but there were no reports of injuries, police Superintendent Ernesto Tagle told The AP. (See photos of 6.9 earthquake that hit Nepal and India.)
Negros Oriental police chief Edward Carranza said that the temblor damaged many houses in Guihulngan, a city of about 180,000 people, and he ordered his men to help displaced residents find shelter. A public market collapsed and a bridge in the city was damaged.
People rushed out of schools, malls and offices during the quake, which hit at 11:49 a.m. (3:49 a.m. GMT). Officials in some areas suspended work and canceled classes. Power and telecommunications were knocked out in several places.
Carranza said policemen rushed out of his building when the quake struck. "All my personnel ran out fearing our building would collapse," he said.
"Now it's shaking again," he said as an aftershock hit. "My keychain is dancing."
The U.S. Geological Survey said the quake was centered 44 miles (72 kilometers) north of Dumaguete city on Negros and hit at a depth of 29 miles (46 kilometers). The area is about 400 miles (650 kilometers) southeast of the capital, Manila.
President Benigno Aquino III's spokesman said authorities did not force people to evacuate but implored those along the shore to be vigilant. The coast guard grounded all vessels while the tsunami alert was in effect.
A mall in San Carlos city in neighboring Negros Occidental province was damaged when its windows were shattered by the shaking, Ramos said. The quake was also felt in Cebu, where it lasted about 30 seconds.
The Philippines is located in the Pacific "Ring of Fire" where earthquakes and volcanic activity are common. A 7.7-magnitude quake killed nearly 2,000 people in Luzon in 1990.

Wednesday, July 19, 2006

Why Indonesia's tsunami alert system is far from ready

http://news.bbc.co.uk/2/hi/asia-pacific/5191190.stm
Indonesia tsunami system 'not ready'
By Laura Smith-Spark
BBC News

Eighteen months after the devastating Indian Ocean tsunami, hundreds have died after a giant wave struck the Indonesian island of Java.

Villagers carry the body of a tsunami victim in Cilacap, central Java
Some villagers say there was little or no warning ahead of the tsunami
Their deaths have raised questions about the failure of a promised Indian Ocean tsunami early warning system to sound an adequate alert.

More than 500 people died when the tsunami struck Java's southern coast on Monday.

Witnesses have said people had little or no warning to flee the 2m-high wave triggered by an undersea earthquake.

Java resident Elan Jayalani, whose village of Batukaras was one of those affected, told the BBC: "There was some confusion about the warning.

"We were told that there had been an earthquake and the tsunami might come in a couple of days... we never expected it."

The new Indian Ocean early warning system - proposed after the December 2004 tsunami which claimed 200,000 lives - was said by the UN to be "up and running" late last year.

So why did a warning not reach Java's affected communities in time?

Indonesian earthquake official Fauzi told the BBC News website that although progress had been made, there were still serious shortcomings in Indonesia's monitoring systems and communications network.

Indonesian police help villagers clear debris in Pangandaran, Java
Many people have been displaced after their homes were destroyed

These were compounded by the speed at which Monday's tsunami struck, said Fauzi, who works for Indonesia's Bureau of Meteorology and Geophysics (BMG).

It currently takes scientists up to 60 minutes to receive and analyse the data from 30 seismological stations and send out a warning.

With only a 20-minute interval between the magnitude 7.7 undersea earthquake and the arrival of the waves on shore, there was just no time to warn people, Fauzi said.

However, work is under way to improve the system.

  • Thirty more seismological stations are to be installed this year

  • A total of 160 will be in place when the network is completed in 2009, cutting the time taken to receive and process earthquake data to less than five minutes

  • At present two ocean pressure sensors - part of the Deep-ocean Assessment and Reporting of Tsunami (Dart) system - are in place. Another 15-20 Dart buoys are planned by 2009

  • Four land-based tide gauges are now in place in Aceh, Nias island, Padang and Bali. An international network spanning the Indian Ocean continues to be updated and expanded

'Unexpected'

The final part of the jigsaw is getting the warning message from tsunami monitoring centres to Jakarta and - in a matter of minutes - to often isolated communities.

[It's] a hard thing to keep up that level of awareness and to have people be able to react quickly when an event occurs
Charles McCreary
Pacific Tsunami Warning Center, Hawaii
Fauzi said: "We don't have the systems yet so what we do is call by telephone. But sometimes the lines are busy and it's very difficult to get through.

"We need to set up an exclusive communication system because otherwise it's going to be the same problem. If we use public communication systems, it's not going to work very well."

In the meantime, officials were making use of SMS messages to contact communities at risk, he said.

Networks of sirens are also being set up this year in the Aceh, Padang and Bali regions to alert people who may be too poor to own TVs, radios or mobile phones. Another is to be built in Java next year.

Awareness level

Educating vulnerable coastal communities so they know how to react if an earthquake strikes or a tsunami warning is issued is also key.

People in Pangandaran, Java, one of the worst-affected areas
It remains difficult to get warning messages to all vulnerable people
When the waters receded before the giant waves hit Java's coast, witnesses reported people running on to the exposed seabed to look - a reaction that cost many lives in the 2004 tsunami.

Charles McCreary, director of the Pacific Tsunami Warning Center in Hawaii, told BBC News that, despite improvements in warning systems, basic safety messages had still not reached everyone.

"The strategy has always been that if you're near the ocean and you feel a strong earthquake, that is your warning and you need to move to high ground or inland as quickly as possible.

"But that's a hard thing to keep up that level of awareness and to have people be able to react quickly when an event occurs - and it looks that there was a failure of that today."

Financial help continues to come from governments and organisations including Germany - a partner in building the Dart system - Japan, China and the UN, Fauzi said.

But, he added, establishing such a complex new monitoring system inevitably "takes time".

"Also, right now, there are difficulties with our human resources because this is our first experience of setting up a tsunami system," he said.

"What we need is to ask the developed countries also to assist us with expertise."

INDONESIA TSUNAMI WARNING SYSTEMS
Map showing Indonesia's tsunami warning systems
Germany, Japan, China and the United Nations, among others, are contributing towards Indonesia's tsunami warning system
Between 15 and 20 Dart buoys are expected to be in place by 2009
Indonesia also has 30 seismographic stations and plans 30 more by end of 2006, 160 by 2009

Thursday, June 29, 2006

Asia tsunami warning system ready

http://news.bbc.co.uk/2/hi/asia-pacific/5126710.stm

Asian tsunami, December 2004
Most had no warning of the 2004 tsunami until giant waves appeared
A tsunami warning system covering the Indian Ocean region is now "up and running", Unesco has said.

The UN organisation, which has overseen the project, says the whole region can now receive and distribute warnings of possible tsunamis.

The system is in place 18 months after the devastating tsunami of December 2004 that killed more than 200,000.

The Pacific region has had a system for 40 years and others are planned for the Atlantic, Mediterranean and Caribbean.

Work unfinished

Koichiro Matsuura, director-general of the UN's scientific and cultural organisation, said the nations involved should be "justly proud of having done all this and much more".

The Asian tsunami hits the Andaman islands in India
The UN says people must know what to do when warned

There are 26 national tsunami information centres receiving information from 25 new seismographic stations.

There are also three deep-ocean sensors to detect and report tsunamis.

But Mr Matsuura warned the work was not yet finished.

He said the system would suffer if there was no coordination between the different nations.

"The open and free exchange of data and the full interoperability of national systems is absolutely crucial for success," he said.

Mr Matsuura also said that even a 100% successful warning system would be ineffective "if people do not know how to respond to the emergency".

The system is being overseen by Unesco's Intergovernmental Oceanographic Commission.

A massive earthquake beneath the ocean on 26 December 2004 sent giant waves crashing ashore in places as far apart as Indonesia, Sri Lanka, Thailand and Somalia.

The only warning most people had was the sight of the waves heading towards them. About 1.5 million people were left homeless in the region after the wall of water stripped away trees, houses and whole communities.

Reconstruction could take between five years and a decade.

Thursday, May 18, 2006

Pacific states hold tsunami test

http://news.bbc.co.uk/1/hi/world/asia-pacific/4988492.stm

A scientist at the Hawaii Pacific Tsunami Warning Centre looks at simulated seismic data on Tuesday
Scientists were pleased with the high participation in the test
More than 30 countries around the Pacific Ocean have tested a system to warn them of approaching tsunamis.

The exercise began with a mock alert at the Tsunami Warning Centre in Hawaii.

According to the scenario, a magnitude 9.2 earthquake had struck near the coast of Chile, sending a tsunami racing across the eastern Pacific.

A second mock alert, involving a make-believe earthquake north of the Philippines, has been testing responses in the western Pacific.

The drill is thought to have been broadly successful, although there was some delays with communications systems in Thailand.

'Success'

Governments are reporting back on how efficiently they received the tsunami warnings, relayed through various circuits including weather services, emails and faxes.

They've contacted each country that is participating and just about every single one of them have received the bulletins
Delores Clark
US National Oceanic and Atmospheric Administration
The aim of the drill, co-ordinated by the Pacific Tsunami Warning Centre in Hawaii, is also to measure how well the message is relayed through local emergency systems.

At the start of the test, a beeping noise sounded throughout the warning centre on Hawaii's Ewa Beach, and within minutes the first alerts were sent out to 30 participating countries.

In a second part of the drill, officials in Thailand, Malaysia, American Samoa and the Philippines staged real tsunami evacuations.

On Wednesday morning, a mock warning of an earthquake north of the Philippines sent nearly 1,000 people in the coastal village of Buhatan scurrying for the hills.

In Malaysia, villages along the coast of Sabah state on Borneo were also evacuated as part of the drill.

"It's gone very, very well so far," a spokeswoman for the US National Oceanic and Atmospheric Administration told AFP news agency at the end of the first stage.

"They've contacted each country that is participating and just about every single one of them have received the bulletins," Delores Clark added.

The second part was not quite as smooth. A crucial link in the communications chain to alert people in Thailand failed to work, a disaster response official said.

The country's National Disaster Warning Centre said the problem was caused by an overloaded telephone system which delayed public text message alerts for several hours.

"This is something we need to improve, otherwise it may cause great damage," Samith Dhammasaroj, the head of the centre, told Reuters news agency.

Real thing

Correspondents say governments' interest in tsunami alerts had waned before the catastrophic Indian Ocean tsunami of December 2004, which took more than 200,000 lives.

An evacuation was planned at a Philippines villages as part of the test
Some countries planned evacuations at coastal areas

Two actual earthquakes struck on Tuesday during the test - a magnitude 7.4 quake north of New Zealand, and a magnitude 6.8 off Indonesia. No casualties were reported.

Another mock test on Wednesday is envisaging a magnitude 8.8 earthquake north of the Philippines.

Officials there, and in Thailand, Malaysia and American Samoa, will go one step further by staging real evacuations.

A Pacific warning system has been in place since 1965, but this is largest test of the system since its inception.

The exercise may serve as a model for future tests in the Indian Ocean.

Monday, December 19, 2005

GPS Could Speed Tsunami Warnings

http://www.wired.com/news/technology/0,1282,69847,00.html?tw=rss.TOP

By Elizabeth Svoboda
02:00 AM Dec. 19, 2005 PT

GPS satellite receivers are already navigational must-haves for hikers and drivers. Now scientists are hatching plans to press them into service as tsunami predictors.

International organizations like the Pacific Tsunami Warning Center, or PTWC, in Hawaii currently depend on coastal seismic stations to record deep-sea earthquakes that could cause giant waves. But according to Jeff Freymueller, a geophysicist at the University of Alaska Fairbanks, data from GPS receivers could provide quicker, more accurate estimates of the magnitude of a tsunami-causing quake, buying time for evacuation. Freymueller presented his findings at this week's American Geophysical Union conference in San Francisco.

Unlike seismometers, GPS receivers can measure the movement of the ground in real time. Because quake magnitude is a direct function of how much the earth shifts, Freymueller has demonstrated that the receivers can obtain precise measurements of a massive quake's severity in as little as 20 minutes.

"Seismometers measure the velocity of the ground, and you have to collect a number of cycles of the important wave in order to get that measurement," he said. "GPS receivers measure the static displacement of the earth, and after the first few minutes of a quake, that doesn't change much."

Freymueller envisions a new tsunami-warning strategy that would use seismic and GPS data in tandem to calculate a wave-causing quake's strength soon after its onset. This would enable more-accurate computer simulations of the coming wave, allowing more-targeted evacuation strategies. Planting the receivers every hundred miles in tsunami-prone areas, he added, could be done in a matter of months, and each receiver would cost less than $10,000.

"Early warnings from GPS could save thousands of lives," he said. "In last year's Indian Ocean tsunami, there were potentially one to two hours for evacuation, had an accurate warning system been in place. Every minute counts."

Seismic measurements of very large quakes like the one that caused last year's Indian Ocean tsunami take several hours to fine-tune, because the moving vibrations must be recorded at a variety of stations in different locations. When the quake that caused the giant Southeast Asian wave first hit, scientists at the PTWC estimated its magnitude at 8.0, but revised their estimate to 8.5 an hour later. After a few more hours passed, a team at Harvard University pegged the quake at 8.9. The final reading, 9.2, was not agreed upon until months afterward.

Yehuda Bock, a geologist at the Scripps Institution of Oceanography, has also investigated the possibilities of using GPS receivers in tsunami-warning systems. His results are similar to Freymueller's, indicating the receivers can gauge the ground movements created by tsunami-causing quakes with unprecedented precision and speed.

"With GPS, the displacements are measured second by second," said Bock, who also presented at the American Geophysical Union conference. "Within 70 seconds you have a good idea of the final deformation." In addition to predicting tsunamis, he thinks GPS modules could be used to monitor the activity of volcanoes and landslides in real time.

Like Freymueller and Bock, Peter MacDoran, a GPS expert who works for George Washington University's Space and Advanced Communications Research Institute, wants to make GPS receivers part of disaster-prediction networks. But he foresees using them in a different way: to track the movement of tsunami-associated pressure waves in the Earth's atmosphere.

"Quakes that cause tsunamis create deformation on the surface of the water, and that causes an atmospheric 'thump,'" MacDoran said. "A compression wave travels into the upper atmosphere, and that disturbance causes subtle changes in the way GPS signals travel." Digital processing of the changed signals coming from nearby receivers would indicate that a tsunami was imminent.

MacDoran has proposed setting up networks of GPS-connected personal computers to monitor these signals, especially in tsunami-prone areas like Southeast Asia, the United States' Atlantic coast and the Pacific Northwest.

He emphasized, however, that his goal is to complement seismic-based tsunami-detection strategies, not replace them. "The quake sensors we have work well. Seismic sensing is a highly developed art," he said. "It just doesn't give you all the information you need."

Friday, December 16, 2005

How to Build a Global Internet Tsunami Warning System in a Month

Cringley is a respected technology forecaster. Here are his words from almost a year ago, and yet we have no such system in place. His idea could work, from my personal reading of the problem statement, it doesn't seem that hard. Where have all the volunteer programmers gone?

-- tsunamiwarning

(Source: http://www.pbs.org/cringely/pulpit/pulpit20041230.html)

December 30, 2004

Wave of Change

How to Build a Global Internet Tsunami Warning System in a Month

By Robert X. Cringely

A friend of mine is missing in southern Asia.

She isn't missing in the sense that anyone saw her swept away by this week's horrible tsunami, but she and her entire family haven't been heard from, either so of course, I am worried. That worry makes real for me a disaster of such horrific proportions that without a personal connection, it simply can't be real to most of us. By the time all the bodies have been counted and estimated, probably 100,000 people will have died. If cholera follows, as it tends to in that part of the world, another 40,000 or more could follow. That's a lot of people, 140,000 -- enough people that we ought to do something to make sure it doesn't happen again. So of course, there is lots of talk about tsunami warning systems and global cooperation, but I think that's just going about solving the problem the wrong way. We don't need governments and huge sensor arrays to warn people on the beach about the next huge wave approaching at 400 miles-per-hour. Thanks to the Internet, we can probably do it by ourselves.

Here's the problem with big multi-government warning systems. First, we have a disaster. Then, we have a conference on the disaster, then plans are proposed, money is appropriated, and three to five years later, a test system is ready. It isn't the final system, of course, but it still involves vast sensor arrays both above and below the surface of the ocean, satellite communication, and a big honking computer down in the bowels of the Department of Commerce or maybe at NASA. That's just the detection part. The warning part involves multilateral discussions with a dozen nations, a treaty, more satellite communication, several computer networks, several television and radio networks, and possibly a system of emergency transmitters. Ten years, a few million dollars and we're ready.

We can't rely on governments to do this kind of work anymore. They just take too darned long and spend too much money for what you get. Besides, since governments are almost totally reactive, what they'll build is a warning system for precisely the tsunami we just had -- a tsunami bigger than any in that region since the eruption of Krakatoa in 1883. One could argue (and some experts probably will) that it might even be a waste of money to build a warning system for a disaster that might not happen for another 121 years.

What we need is a tsunami warning system not just for parts of Asia, but for anywhere in the world that might be subject to such conditions. And that decision about what beaches to protect ought to come not from Washington, D.C., or Jakarta, or any other capital city, but from the beach people, themselves. If you are concerned about a giant tidal wave taking out your village, it might be a good idea to build your own warning system, you retired engineer, you Radio Shack manager, you harbor master, you radio amateur, you nerd with a suntan.

It can be done.

The Tsunami Warning System (TWS) in the Pacific Ocean shows us how such a warning system can be run with the cooperation of 26 countries. Maybe we can do the same thing, just without all that cooperation. TWS is based on crunching two kinds of data -- seismic activity and changes in sea level measured by tide gauges. Most tsunamis begin with an earthquake, the severity and epicenter of which can tell a lot about whether a tsunami is likely, how strong it will be, and in what direction it is likely to go. From the TWS, the first warning is based purely on such seismic data. But once the big wave starts rolling it will have an effect on the level of the sea, itself, which is routinely monitored by weather stations of many types. This additional data gives a better idea of how bad the wave is really going to be, so in the TWS system, it is used to justify expanding the warning to other communities beyond those warned purely on the basis of seismic data.

Depending on where the originating earthquake is, the tsunami can be minutes or hours from crashing into a beach. This week's wave took about 90 minutes to reach Sri Lanka, just over 600 miles from the epicenter. That not only means the wave was traveling at over 400 miles-per-hour, it also means that had a warning system been in place, there would easily have been time to get the people who were affected in Sri Lanka to higher ground.

So to start, we need raw seismic data. If you take a look at the fourth of this week's links, you'll see that plenty of such data are available. Thanks to the Pacific Northwest Seismograph Network, here is one place where you can find real time data from 199 seismographs around the world. There are also links to a dozen regional operations that consolidate such data. The data is available. Tide gauge data is available, too, though there is less of it, and aggregation will require more effort, so I say let's just stick to seismic data for our warning system.

Here's where we need the help of a tsunami expert, someone who can help us calculate the size and direction of a likely tsunami based on the available seismic data. Fortunately, there has been quite a bit of work done in this area of study (see link #5), and appropriate computer codes that can be run on a personal computer either exist or can be derived, perhaps by reflexively evaluating seismic data from known tsunami events. But remember that what we care about here is not global tsunami warning but LOCAL tsunami warning (Is it going to hit MY beach?), so the required seismic data sources can pretty easily be limited to those with an uninterrupted aspect of the target beach, which means half a dozen seismographs, not 199.

Since the basic question is fairly simple -- "Is my beach going to be hit by a destructive tsunami and when?" -- and the required data sources are limited, I figure we won't need a supercomputer.

The seismographs are online, we gather the data using XML, continuously crunch it using the codes I am assuming already exist, then we need the warning, which I would flash on the screen of my PC down at the surf shop using a Javascript widget built with Konfabulator, the most beautiful widget generator of all. Looking just like a TV weather map, the widget would flash a warning and even include a countdown timer just like in the movies.

You don't need an international consortium to build such a local tsunami warning system. You don't even need broadband. The data is available, processing power is abundant and cheap. With local effort, there is no reason why every populated beach on earth can't have a practical tsunami warning system up and running a month from now. That's Internet time for you, but in this case, its application can protect friends everywhere from senseless and easily avoidable death.

Links of the Week

Computerworld
Computerworld says we need a tsunami warning network.
(http://www.computerworld.com/managementtopics/management/
itspending/story/0,10801,98582,00.html?source=NLT_PM&nid=98582)

Krakatoa
Krakatoa in 1883 was a far bigger seismic event, but loss of life was less simply because the coastal populations then were smaller.
(http://www.alertnet.org/thenews/newsdesk/SP134319.htm)

Tsunami Warning System
There already is a tsunami warning system for the Pacific Ocean, just not one for the Indian Ocean.
(http://www.geophys.washington.edu/tsunami/general/
warning/warning.html)

Raw Seismic Data
Raw seismic data and plenty of it.
(http://www.geophys.washington.edu/seismosurfing.html)

Konfabulator
Konfabulator, my favorite widget builder.
(http://www.konfabulator.com)

Official announcement : An Indian Tsunami early warning system in the Indian Ocean soon

Thursday, December 15, 2005

PRESS INFORMATION BUREAU, GOVERNMENT OF INDIA

SETTING UP OF AN EARLY WARNING SYSTEM FOR TSUNAMI AND STORM SURGES IN INDIAN OCEAN

16:41 IST

Rajya Sabha

The Government is setting up an Early Warning system for Tsunami and Storm Surges in Indian Ocean at the total cost of Rs. 125 crores with the following components:

Strengthening of the existing seismological network to indicate, near real time occurrence of tsunamigenic earthquakes;

Installation of tsunami warning sensors close to the ocean bottom at appropriate locales in the Indian Ocean, with real time connectivity;

Tide gauge and data buoys networking to validate arrival of tsunami waves at the coast;

Modelling of the inundation scenarios for the entire coast and mapping of potential risk areas;

Collection of information, analysis and generating status advisories.

A centre would be set up at Indian National Centre for Ocean Information Services (ICOIS), Hyderabad, Andhra Pradesh on a 24X7 basis. The system is scheduled to be operationalized by September, 2007. The Tsunami Warning System is for the whole country.

In a written reply in Rajya Sabha, the Minister for Science and Technology and Ocean Development, Shri Kapil Sibal said there is no assistance taken from foreign firms in this regard. He said the Indian system is the best system for our country.

PRA:AD:NC

Monday, March 28, 2005

Evacuation in progress in Chennai

[11:55 PM 3/28/2005]

I've heard from my family in Chennai that the residents along the Elliots beach in Chennai are being evacuated. However, news reports are indicating that the tsunami has been milder this time, and it is heading away from India and towards Mauritius.

Fresh quake reported off the coast of Sumatra - 8.5

[NEWS LINK]



Quake off Indonesia triggers tsunami fears

By Associated Press | March 28, 2005

BANDA ACEH, Indonesia -- A major earthquake struck off the west coast of Indonesia's Sumatra Island late Monday, and officials warned that a tsunami could strike the area. Residents of Banda Aceh fled their homes in panic.

The U.S. Geological Survey said the temblor, described by one of the agency's geologists as an aftershock of the devastating Dec. 26 quake, measured a magnitude of 8.2.

Officials issued a tsunami warning for residents of southern Thai provinces, three months after a tsunami devastated parts of Indonesia and other countries in the region. The quake occurred at 11:09 p.m. local time at a depth of nearly 19 miles, the USGS in Golden, Colo., said.

Japan's Meteorological Agency said the quake registered 8.5.

Tremors were felt throughout peninsular Malaysia's west coast, causing thousands of residents to flee high-rise apartment buildings and hotels. There were no immediate reports of any casualties or major damage.

"I was getting ready for bed, and suddenly, the room started shaking," said Kuala Lumpur resident Jessie Chong. "I thought I was hallucinating at first, but then I heard my neighbors screaming and running out."

Chalermchai Aekkantrong, deputy director of Thailand's meteorological department, told a radio station that officials were asking people near the coast to evacuate, although there were no immediate reports of a tsunami.

Tremors form the quake could be felt in the Thai capital Bangkok for several minutes beginning at about 11:20 p.m.

The Dec. 26 magnitude-9 undersea earthquake, the world's biggest in 40 years, and the huge tsunami it sent charging across the Indian Ocean at the speed of a passenger jet killed more than 174,000 people and left another 106,000 missing.

More than 1.5 million people were left homeless in 11 countries.