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Showing posts with label Tsunami Warning. Show all posts
Showing posts with label Tsunami Warning. Show all posts
Wednesday, 6 February 2013
Image: Earthquake and Tsunami Damage Solomon Islands
Disaster Report - First photo of disaster in Solomon Islands, Santa Cruz Islands. Tsunami in Solomon Islands has destroyed more than 50 houses.
DR: It is just the preliminary report obtained from locals in Solomon.
We have currently no report of injured people.
Several houses reported to be flooded in eastern Temotu province of Solomon Islands.
- Solomon Times
PUBLIC TSUNAMI INFORMATION STATEMENT NUMBER 3 NWS WEST COAST/ALASKA TSUNAMI WARNING CENTER PALMER AK
721 PM PST TUE FEB 5 2013
THIS IS THE FINAL INFORMATION STATEMENT FOR THIS EVENT.
...THIS IS A TSUNAMI INFORMATION STATEMENT FOR ALASKA/ BRITISH
COLUMBIA/ WASHINGTON/ OREGON AND CALIFORNIA...
EVALUATION
----------
* NO TSUNAMI THREAT EXISTS FOR THE AREAS LISTED ABOVE.
* SOME OF THE AREAS LISTED ABOVE MAY EXPERIENCE NON-DAMAGING
SEA LEVEL CHANGES.
* SEA LEVEL OBSERVATIONS INDICATE A TSUNAMI WAS GENERATED.
PRELIMINARY EARTHQUAKE PARAMETERS
---------------------------------
* MAGNITUDE 8.0
* ORIGIN TIME 1613 AKST FEB 05 2013
1713 PST FEB 05 2013
0113 UTC FEB 06 2013
* COORDINATES 10.9 SOUTH 165.1 EAST
* DEPTH 21 MILES
* LOCATION SANTA CRUZ ISLANDS
OBSERVATIONS OF TSUNAMI ACTIVITY - UPDATED
------------------------------------------
TIME OBSERVED MAX
SITE OF MEASUREMENT TSUNAMI HEIGHT
---------------------------- --------------- --------------
LATA WHARF SOLOMON ISL 0131 UTC 02-06 03.4FT
DART52406PT NE GUADALCA 0211 UTC 02-06 00.3FT
DART55012ST SE CORAL SE 0232 UTC 02-06 00.4FT
HONIARA SOLOMON ISLAND 0307 UTC 02-06 00.2FT
PORT VILA VANUATU 0303 UTC 02-06 00.6FT
HEIGHT - OBSERVED MAX TSUNAMI HEIGHT IS THE WATER LEVEL ABOVE THE
TIDE LEVEL AT THE TIME OF MEASUREMENT.
NEXT UPDATE AND ADDITIONAL INFORMATION
--------------------------------------
* THIS WILL BE THE FINAL WCATWC MESSAGE FOR THIS EVENT
UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE.
* REFER TO THE INTERNET SITE WCATWC.ARH.NOAA.GOV FOR
ADDITIONAL INFORMATION.
* PACIFIC COASTAL REGIONS OUTSIDE CALIFORNIA... OREGON...
WASHINGTON... BRITISH COLUMBIA AND ALASKA SHOULD REFER TO THE
PACIFIC TSUNAMI WARNING CENTER MESSAGES AT PTWC.WEATHER.GOV.
- NOAA
Pacific Tsunami Warning Centre cancelled tsunami warning for......
Update 05:50 UTC - Finally a relief!
THE TSUNAMI WARNING ISSUED BY THE PACIFIC TSUNAMI WARNING CENTER IS NOW CANCELLED FOR
SOLOMON ISLANDS / VANUATU / NAURU / PAPUA NEW GUINEA / TUVALU /
NEW CALEDONIA / KOSRAE / FIJI / KIRIBATI / WALLIS AND FUTUNA
Quake off Solomon Islands triggers tsunami
A small tsunami hit the eastern Solomon Islands after a magnitude 8.0 earthquake that triggered tsunami warnings for several Pacific nations.
The quake struck at 01:12 GMT near the Santa Cruz islands, part of the Solomon Islands nation, the US Geological Survey said.
A tsunami measuring 0.9m (3ft) subsequently hit Lata in the far eastern Solomons.
The centre said the tsunami could be destructive near the epicentre.
"Sea level readings indicate a tsunami was generated," the Hawaii-based centre said.
"It may have been destructive along coasts near the earthquake epicentre and could also be a threat to more distant coasts."
Initial reports by the USGS said the quake had a shallow depth of 5.8km (3.6 miles) but it later revised the figure to 28.7km (17.8 miles).
The tsunami warning was issued for the Solomon Islands, Vanuatu, Nauru, Papua New Guinea, Tuvalu, New Caledonia, Kosrae, Fiji, Kiribati, and Wallis and Futuna islands.
A tsunami watch was issued for other nations in the South Pacific, including Australia, New Zealand and Indonesia. However, the Australian Bureau of Meteorology later said Australia was not at risk from a tsunami.
France issued a tsunami warning for its New Caledonia territory, saying that the wave could strike at about 03:00 GMT. Residents near the coast were being advised to evacuate.
Irene Scott, a reporter with Paoa FM on the Solomon Islands, told the BBC there were reports of houses being inundated in eastern Temotu province, but no serious damage or injuries.
The Solomon Islands form part of the Ring Of Fire, a zone of volcanic arcs and oceanic trenches encircling the Pacific basin.
The 8.0 earthquake was followed by several aftershocks, the largest measuring 6.6 magnitude.
The region has been experiencing a series of smaller quakes in recent days.
In 2007 an 8.1 magnitude earthquake triggered a tsunami that killed at least 52 people in the Solomons and left thousands homeless.
-BBC
Powerful quake in South Pacific triggers 3-foot tsunami
A 3-foot tsunami was generated after a strong earthquake shook the islands in the South Pacific, the Pacific Tsunami Warning Center said.
The U.S. Geological Survey says the quake -- with a preliminary magnitude of 8.0 -- struck Wednesday in the Santa Cruz Islands at a depth of about 3 miles. The Santa Cruz Islands are scarcely populated and are part of the Solomon Islands.
A magnitude 6.4 aftershock occurred shortly after the first rumble, followed by a 6.6 one later. USGS officials said that was "not at all surprising."
Hotel workers on Vanuatu said they felt the earthquake but have not heard of any damage or injuries. An employee who can see the coast from a hotel said he had not noticed any water coming in.
The tsunami warning was in effect for the Solomon Islands, Vanuatu, Nauru, Papua New Guinea, Tuvalu, New Caledonia, Kosrae, Fiji, Kiribati, Wallis and Futana. A tsunami watch was in effect for Samoa, New Zealand, Australia, Indonesia and Guam.
- NBCNews.com
The U.S. Geological Survey says the quake -- with a preliminary magnitude of 8.0 -- struck Wednesday in the Santa Cruz Islands at a depth of about 3 miles. The Santa Cruz Islands are scarcely populated and are part of the Solomon Islands.
A magnitude 6.4 aftershock occurred shortly after the first rumble, followed by a 6.6 one later. USGS officials said that was "not at all surprising."
Hotel workers on Vanuatu said they felt the earthquake but have not heard of any damage or injuries. An employee who can see the coast from a hotel said he had not noticed any water coming in.
The tsunami warning was in effect for the Solomon Islands, Vanuatu, Nauru, Papua New Guinea, Tuvalu, New Caledonia, Kosrae, Fiji, Kiribati, Wallis and Futana. A tsunami watch was in effect for Samoa, New Zealand, Australia, Indonesia and Guam.
- NBCNews.com
M8.0 - SANTA CRUZ ISLANDS 2013-02-06 01:12:27 UTC
Summary
Location and Magnitude contributed by: USGS, NEIC, Golden, Colorado (and predecessors)
Event Time
- 2013-02-06 01:12:27 UTC
- 2013-02-06 03:12:27 UTC+02:00 system time
Location
10.738°S 165.138°E depth=28.7km (17.8mi)Related Links
Additional Data Contributors
Thursday, 8 November 2012
Report: Strong quake off Guatemala is felt in Mexico City
A strong earthquake struck off the Pacific coast of Guatemala on Wednesday, shaking buildings in Guatemala City and San Salvador, and was felt as far away as Mexico City, witnesses told Reuters.
There were no immediate reports of damage or injuries.
The U.S. Geological Survey said the magnitude-7.5 quake struck 28 miles southwest of Champerico, Guatemala, near the border with Mexico. The epicenter was 25 miles below the surface.
CONRED, the government office for reduction of disasters in Guatemala, told NBC News an aerial evaluation of affected neighborhoods was being carried out amid reports of walls collapsing in homes and the loss of power and telephone services.
The manager of the Grand Tikal Futura Hotel in the capital, Guatemala City, told NBC News that she felt a "strong earthquake" but that the building had sustained no damage and guests were returning to their rooms.
A Reuters witness in Guatemala City said people were evacuating homes in parts of the capital, and firefighters and rescue workers were on alert. Office workers were also evacuating buildings in Mexico City.
The Pacific Tsunami Warning Center did not issue a tsunami warning, Reuters reported.
- NBCNEWS
There were no immediate reports of damage or injuries.
The U.S. Geological Survey said the magnitude-7.5 quake struck 28 miles southwest of Champerico, Guatemala, near the border with Mexico. The epicenter was 25 miles below the surface.
CONRED, the government office for reduction of disasters in Guatemala, told NBC News an aerial evaluation of affected neighborhoods was being carried out amid reports of walls collapsing in homes and the loss of power and telephone services.
The manager of the Grand Tikal Futura Hotel in the capital, Guatemala City, told NBC News that she felt a "strong earthquake" but that the building had sustained no damage and guests were returning to their rooms.
A Reuters witness in Guatemala City said people were evacuating homes in parts of the capital, and firefighters and rescue workers were on alert. Office workers were also evacuating buildings in Mexico City.
The Pacific Tsunami Warning Center did not issue a tsunami warning, Reuters reported.
- NBCNEWS
Thursday, 1 November 2012
Hawaii Hams Activate for Tsunami Warning
On Saturday, October 27, radio amateurs in Hawaii responded to a tsunami warning, providing valuable and timely information to emergency management officials. The tsunami was triggered by a magnitude 7.7 earthquake which struck at struck at 5:04 PM HST (0304 UTC on Sunday, October 28) in the Queen Charlotte Islands, located off the coast of British Columbia, Canada.
At 7:14 PM*, the Pacific Tsunami Warning Center (PTWC) sent out a tsunami warning and said that the tsunami had an estimated wave arrival time of 10:28 PM. After being notified, Hawaii State Civil Defense RACES Coordinator Ron Hashiro, AH6RH, began notifying Oahu leaders via cell phone while ARRL Hawaii Section Emergency Coordinator Kevin Bogan, AH6QO, began activating the ARES Emergency Coordinators on each island.
“The initial telephone alert process took 12 minutes and radio operators continued the coordination and activation while driving to the Emergency Operations Centers and points of operation,” Hashiro told the ARRL. “Chuck Oh, N6NCT, on Oahu activated the Department of Emergency Management (DEM) RACES organization and eight hams responded to the Oahu EOC. Tom Geier, KH6BLA, served as net control on the DEM net on the 146.88 MHz repeater with 35 hams checking in. Clem Jung, KH7HO, and Rick Kimitsuka, KH6OM, led eight hams in DEM District IV -- along the Windward Coast of Oahu -- and operated on the 146.66 MHz Olomana and 146.64 Laie repeaters and simplex frequencies.”
According to Hashiro, Mel Fukunaga, KH6H, went to the Maui EOC, while Harvey Motomura, AH6JA, went to the Hilo EOC, located on the Big Island. “The Community Emergency Response Teams (CERT) on Upcountry Maui on the slopes of Mt Haleakala responded to provide coverage for the communities in that area,” he explained. “Nancy Kala, WH7XO, coordinated the activities of both hams and non-ham CERT members. Several hams operated on the Healthcomm 80 meter frequency, led by Jack Tsujimura, KH6DQ, who served as net control.”
State Civil Defense (SCD) RACES radio operators arrived onsite at the SCD Emergency Operations Center in Diamond Head Crater and began operations at 8:02 PM. Hashiro and Bogan teamed up as operators on the interisland VHF repeater system, sharing control between a radio and a PC connected to the Allstar controller for the 147.06 MHz repeater -- located on the rim of Diamond Head Crater -- via the Internet. “Larry Sue, AH6SP, manned the 40 meter HF radio, and Robin Liu, AH6CP, ran the Oahu Allstar linked VHF/UHF repeater network,” Hashiro said. “This network is comprised of four linked VHF and UHF repeaters and uses a PC connected via the Internet; it is monitored Hawaii’s Department of Emergency Management (DEM) net on the Diamond Head 146.88 MHz repeater. Messages received via radio were sent by the internal e-mail to both the State Warning Point and Operations Desk.”
Hashiro explained that the nets handled various tactical messages regarding communication checks, the progress of preparations and the arrival of people at the designated tsunami refuge centers, as well as road closures near the waterfront. The sirens on Oahu sounded at 8 PM, which was less than the prescribed three-hour lead time notice normally given for sounding the first sirens. The sirens on Maui sounded at 8:25 PM, and the sirens on the west coast of the Big Island sounded at 8:33 PM, as reported by the resident hams.
At 10 PM, the State Civil Defense net changed reporting formats, going from “normal” to only requesting tactical message traffic that included estimates of changes to the ocean level. But due to darkness and the evacuation, Hashiro said that not many hams were in position to see ocean level changes.
Kalani Ku, WH6KX, was with Maui Police Department officers on the north side of Maui at Kahului Harbor, and passed along timely reports of ocean level changes from each passing wave. “Ku had previous experience reporting wave heights during the February 2010 Chilean tsunami, and at 10:53 PM, he noted the water receding from the harbor by a level of two to three feet,” Hashiro said. “His reports over the next hour of +2 feet and -3 feet changes mirrored the measurements of the tide gauges monitored by the PTWC. The tide gauges at Kahului Harbor recorded the greatest level changes during this event, and Amateur Radio reported the results in real time.”
Dave Garrison, AL4A, monitored and reported the successive waves from the Pacific Whale Foundation location at Maalaea, located near Kihei on Maui’s south shore, with reports ranging from +2 feet and -3 feet. “This was Dave’s first experience filing real-time tsunami reports,” Hashiro noted. “The differing ocean levels reported almost concurrently by Ku and Garrison demonstrated the effects and delay of the tsunami waves from Canada wrapping around the island of Maui.”
Hams at the different EOCs, including the State EOC and the Maui and Oahu County EOCs, received these reports simultaneously and in real time. “At the SCD, the personnel at the county EOCs and the PTWC held periodic video conferences to discuss these recent reports and make forecasts and determinations for the next interim period,” Hashiro told the ARRL. “ARRL Hawaii SEC Kevin Bogan, AH6QO -- who has a regular position as a State Warning Point Supervisor at SCD -- was off duty at the time, but he sat in as a representative of SCD RACES. With the approval of the Operations Chief and Vice Director, Kevin contributed the reports by the hams to the videoconference, which helped the PTWC confirm the assessment and forecast of the prevailing conditions. The determination was made to downgrade the warning to an advisory effective at 12:54 AM on Sunday, October 28.” The SCD net secured at 1:05 AM, and the operators at DEM secured about an hour later.
“This event proved a challenge in getting the initial notification and coordination going,” Hashiro explained. “One of the complicating factors in the initial alert was some team members were looking at the previous PTWC bulletin for Hawaii that didn’t contain the warning for Hawaii. They were fixated on the embedded information product issued by the West Coast and Alaska Tsunami Warning Center at Palmer, Alaska that contained a regional warning for Washington, Oregon and California only. There was a slight delay to pull up and read the latest Hawaii bulletin to confirm receiving the latest status. Others had subscribed to e-mail alerts from non-government websites, and those relayed the Pacific Ocean bulletins and not the bulletins for Hawaii. That bulletin indicated no wide-spread tsunami threat for the Pacific, and it was not updated for the change in Hawaii status. The other factor was the alert was received on a Saturday evening during the dinner hour.”
Hashiro told the ARRL that one of the changes being looked at is “to identify and task bulletin stations to receive the alert notification early from one of the leaders, and put out a bulletin immediately on the key repeater frequencies, while the rest of the telephone call down list is still in progress. That would keep stations on standby on the net frequencies until the official confirmations are received to formally activate a response. By keeping the nets focused, simplifying the reports and requesting only the essential information to be reported, the radio amateurs involved were able to sustain and accomplish their mission of real-time reporting to the EOCs. Both veteran operators and newcomers were successfully integrated into the various reporting nets.”
* All times are Hawaii Standard Time (+10 UTC) unless otherwise noted.
- ARRL
Sunday, 28 October 2012
Tsunami warning for Hawaii downgraded; evacuation orders lifted
(Reuters) - A tsunami warning for Hawaii has been downgraded to an advisory on Sunday, the Pacific Tsunami Warning Center said.
Evacuation orders were also lifted for coastal areas, a Hawaii civil defense official said.
At least 100,000 people in Hawaii were ordered to move from the shoreline to higher ground late on Saturday after a tsunami warning, but the first waves were less forceful than had been feared and no damage was initially reported.
The tsunami was triggered by a powerful earthquake off Canada's Pacific coast.
- REUTERS
Evacuation orders were also lifted for coastal areas, a Hawaii civil defense official said.
At least 100,000 people in Hawaii were ordered to move from the shoreline to higher ground late on Saturday after a tsunami warning, but the first waves were less forceful than had been feared and no damage was initially reported.
The tsunami was triggered by a powerful earthquake off Canada's Pacific coast.
- REUTERS
Smaller-than-expected tsunami hits Hawaii after Canada earthquake
Eugene Tanner / AP - Visitors and Oahu residents watch the water level in the Ala Wai Harbor in Hawaii for the arrival of a tsunami on Saturday.
Updated at 7:35 a.m. ET: A tsunami warning that spurred coastal evacuations throughout Hawaii was downgraded to a tsunami advisory, ending the threat of serious damage, the state's governor said early on Sunday.
At least 100,000 people were ordered to move from the shoreline to higher ground late on Saturday after the tsunami warning, but the first waves were less forceful than had been feared and no damage was initially reported.
The tsunami, triggered by a powerful earthquake off Canada's Pacific coast, began shortly after 10:30 p.m. Hawaii time (4:30 a.m. ET), according to the Pacific Tsunami Warning Center, as motorists clogged roadways in a mass exodus from low-lying areas.
"The tsunami arrived about when we expected it should," Senior Geophysicist Gerard Fryer told reporters at a news conference, saying: "I was expecting it to be a little bigger."
Officials earlier warned locals to treat the threat as very serious.
The height of the first surge initially was put at three feet, but the warning center subsequently reported that early tsunami wave activity peaked at just 2.5 feet at the island of Maui.
There were no immediate reports of serious flooding or damage, but officials warned that additional waves were still possible and that wave heights of up to 6 feet could be reached in some places.
Following the initial surge, Carlisle said it was unclear if the worst had yet passed.
Tsunami warning sirens in the islands were activated on short notice due to initial confusion among scientists about the quake's undersea epicenter and the extent of the tsunami threat posted by the temblor.
Carlisle announced that all police and emergency personnel were being pulled out from potential flood zones shortly before the first wave, leaving anyone defying evacuation orders to fend for themselves. He urged motorists who remained caught in harm's way due to gridlocked roads to abandon their vehicles and proceed on foot.
"If you are stuck in traffic, you might consider getting out of your car and consider walking to higher ground. You will have to assess your own situation, depending on where you are right now. Right now it is critical," he said.
Governor Neil Abercrombie issued an emergency proclamation for the state.
Canada quake
The warnings followed a powerful earthquake with a magnitude of 7.7 that hit Canada's Pacific coastal province of British Columbia late on Saturday.
The U.S. Geological Survey said the quake was centered 123 miles south-southwest of Prince Rupert at a depth of 6.2 miles.
The Earthquakes Canada agency said the quake was followed by numerous aftershocks as large as magnitude 4.6 and that a small tsunami has been recorded by a deep-ocean pressure sensor.
On Oahu, Hawaii's most populous island, tsunami warning sirens could be heard blaring out across Honolulu, the state capital, prompting an immediate crush of traffic, with many motorists stopping at service stations to top up with gasoline. At movie theaters, films were halted in mid-screening as announcements were made urging patrons to return to their homes.
The last time Oahu had a tsunami warning was after the devastating Japanese earthquake of March 2011.
NBC News' Wilson Rothman, who was staying on the island of Kauai, said that while there had been no noticeable rise in water levels, local officials and hotel staff had taken precautions.
"Non-essential hotel functions were shut down fast, and restaurants across the island closed early," he said. "Our hotel asked all guests to evacuate 'vertically' to the 4th, 5th or 6th floor, and asked guests on those floors to 'make new friends'."
On Honolulu's famed Waikiki Beach, residents of high-rise buildings were told to move to the third floor or higher for safety.
Stephany Sofos, a resident of Diamond Head near Waikiki, said most people had either evacuated or relocated to a higher floor.
"I moved my car up the hill, packed up my computer and have my animals all packed and with me," Sofos said, saying that she had not yet seen any obvious receding of the surf, a telltale sign that a tsunami wave is imminent.
"I'm pretty confident because we have a lot of reefs out there and that will prevent any major damage. Maybe it's a false confidence, but I'm not really worried," she said, adding, "It is nerve-wracking."
Tsunami Warning Center Geophysicist Gerard Fryer said the tsunami had caught scientists by surprise.
"We thought that the earthquake was on land and when we learned that it was deeper undersea and we gathered more information, we had no choice but to issue a warning," he said.
As residents scrambled to reach higher ground on Oahu, at least four major road accidents were reported by the state Emergency Medical Services. More accidents were also reported on the outer islands.
A tsunami advisory was also posted for coastal areas of northern California and Oregon, where a maximum sea level rise was estimated at 6 inches, the National Weather Service said. The agency said no significant flooding was expected.
Reuters and The Associated Press contributed to this report.
- MSNBC
Tsunami hits Hawaii after Canada earthquake
HONOLULU, Oct 27 (Reuters) - Hawaii was hit by a tsunami on Saturday night prompting the authorities to order at least 100,000 people on the island state to move to higher ground.
The Pacific Tsunami Warning Center said the first tsunami wave was three feet high and less forceful than expected. Some forecasts had predicted a wave of up to six feet high.
"The tsunami arrived about when we expected it should," Senior Geophysicist Gerard Fryer told reporters at a news conference, saying: "I was expecting it to be a little bigger."
Other waves were expected.
The tsunami hit with little warning and an alert, issued at short notice due to initial confusion among scientists about the quake's undersea epicenter, caused massive traffic congestion as motorists made a mass exodus from low-lying areas.
The Warning Center had said the first tsunami wave would strike the islands at 10:28 p.m. Hawaii Standard Time.
Honolulu Mayor Peter Carlisle announced that all police and emergency personnel were being pulled out from potential flood zones shortly before the first wave, leaving anyone defying evacuation orders to fend for themselves. He urged motorists who remained caught in harm's way due to gridlocked roads to abandon their vehicles and proceed on foot.
"If you are stuck in traffic, you might consider getting out of your car and consider walking to higher ground. You will have to assess your own situation, depending on where you are right now. Right now it is critical," he said
Vindell Hsu, a geophysicist at the Tsunami Warning Center said an estimated 100,000 to 150,000 people who live in Hawaii's coastal zones had been urged to move to higher ground until after 10:30 p.m.
Governor Neil Abercrombie issued an emergency proclamation for the state.
The tsunami center cautioned that wave height could not be predicted and that the first wave "may not be the largest".
It said: "All shores are at risk no matter which direction they face".
CANADA QUAKE
The warnings followed a powerful earthquake with a magnitude of 7.7 that hit Canada's Pacific coastal province of British Columbia late on Saturday.
The U.S. Geological Survey said the quake was centred 123 miles (198 km) south-southwest of Prince Rupert at a depth of 6.2 miles (10 km).
The Earthquakes Canada agency said the quake in the Haida Gwaii region was followed by numerous aftershocks as large as 4.6 and that a small tsunami has been recorded by a deep-ocean pressure sensor.
In Hawaii, tsunami warning sirens could be heard blaring out across Honolulu, the state capital on Oahu, the state's most populous island, prompting an immediate crush of traffic, with many motorists stopping first at service stations to top up with gasoline.
At movie theaters, films were halted in mid-screening as announcements were made urging patrons to return to their homes.
The last time Oahu had a tsunami warning was after the devastating Japanese earthquake of March 2011.
On Honolulu's famed Waikiki Beach, residents of high-rise buildings were told to move to the third floor or higher for safety.
Stephany Sofos, a resident of Diamond Head near Waikiki, said most people had either evacuated or relocated to a higher floor.
"I moved my car up the hill, packed up my computer and have my animals all packed and with me," Sofos said, saying that she had not yet seen any obvious receding of the surf, a telltale sign that a tsunami wave is imminent.
"I'm pretty confident because we have a lot of reefs out there and that will prevent any major damage. Maybe it's a false confidence, but I'm not really worried," she said, adding, "It is nerve-wracking."
Tsunami Warning Center Geophysicist Gerard Fryer said the tsunami had caught scientists by surprise.
"We thought that the earthquake was on land and when we learned that it was deeper undersea and we gathered more information, we had no choice but to issue a warning," he said
As residents scrambled to reach higher ground on Oahu, at least four major road accidents were reported by the state Emergency Medical Services. More accidents were also reported on the outer islands. (Reporting by Jorene Barut and Suzanne Roig in Honolulu; Writing by Steve Gorman and Tim Gaynor; Editing by Andrew Osborn)
- Reuters
The Pacific Tsunami Warning Center said the first tsunami wave was three feet high and less forceful than expected. Some forecasts had predicted a wave of up to six feet high.
"The tsunami arrived about when we expected it should," Senior Geophysicist Gerard Fryer told reporters at a news conference, saying: "I was expecting it to be a little bigger."
Other waves were expected.
The tsunami hit with little warning and an alert, issued at short notice due to initial confusion among scientists about the quake's undersea epicenter, caused massive traffic congestion as motorists made a mass exodus from low-lying areas.
The Warning Center had said the first tsunami wave would strike the islands at 10:28 p.m. Hawaii Standard Time.
Honolulu Mayor Peter Carlisle announced that all police and emergency personnel were being pulled out from potential flood zones shortly before the first wave, leaving anyone defying evacuation orders to fend for themselves. He urged motorists who remained caught in harm's way due to gridlocked roads to abandon their vehicles and proceed on foot.
"If you are stuck in traffic, you might consider getting out of your car and consider walking to higher ground. You will have to assess your own situation, depending on where you are right now. Right now it is critical," he said
Vindell Hsu, a geophysicist at the Tsunami Warning Center said an estimated 100,000 to 150,000 people who live in Hawaii's coastal zones had been urged to move to higher ground until after 10:30 p.m.
Governor Neil Abercrombie issued an emergency proclamation for the state.
The tsunami center cautioned that wave height could not be predicted and that the first wave "may not be the largest".
It said: "All shores are at risk no matter which direction they face".
CANADA QUAKE
The warnings followed a powerful earthquake with a magnitude of 7.7 that hit Canada's Pacific coastal province of British Columbia late on Saturday.
The U.S. Geological Survey said the quake was centred 123 miles (198 km) south-southwest of Prince Rupert at a depth of 6.2 miles (10 km).
The Earthquakes Canada agency said the quake in the Haida Gwaii region was followed by numerous aftershocks as large as 4.6 and that a small tsunami has been recorded by a deep-ocean pressure sensor.
In Hawaii, tsunami warning sirens could be heard blaring out across Honolulu, the state capital on Oahu, the state's most populous island, prompting an immediate crush of traffic, with many motorists stopping first at service stations to top up with gasoline.
At movie theaters, films were halted in mid-screening as announcements were made urging patrons to return to their homes.
The last time Oahu had a tsunami warning was after the devastating Japanese earthquake of March 2011.
On Honolulu's famed Waikiki Beach, residents of high-rise buildings were told to move to the third floor or higher for safety.
Stephany Sofos, a resident of Diamond Head near Waikiki, said most people had either evacuated or relocated to a higher floor.
"I moved my car up the hill, packed up my computer and have my animals all packed and with me," Sofos said, saying that she had not yet seen any obvious receding of the surf, a telltale sign that a tsunami wave is imminent.
"I'm pretty confident because we have a lot of reefs out there and that will prevent any major damage. Maybe it's a false confidence, but I'm not really worried," she said, adding, "It is nerve-wracking."
Tsunami Warning Center Geophysicist Gerard Fryer said the tsunami had caught scientists by surprise.
"We thought that the earthquake was on land and when we learned that it was deeper undersea and we gathered more information, we had no choice but to issue a warning," he said
As residents scrambled to reach higher ground on Oahu, at least four major road accidents were reported by the state Emergency Medical Services. More accidents were also reported on the outer islands. (Reporting by Jorene Barut and Suzanne Roig in Honolulu; Writing by Steve Gorman and Tim Gaynor; Editing by Andrew Osborn)
- Reuters
Tsunami warning issued for Hawaii after British Columbia quake
(Reuters) - A tsunami warning has been issued for the U.S. state of Hawaii after a 7.7 magnitude earthquake struck off the coast of Canada's British Columbia province late on Saturday.
The Pacific Tsunami Warning Center issued the alert, saying that the first tsunami wave could strike the islands at 10:28 pm Hawaii Standard Time.
People living in coastal zones were told to move to higher ground until after 10:30 p.m.
(Reporting By Suzanne Roig; Writing by Peter Henderson; Editing by Andrew Osborn)
- Reuters
The Pacific Tsunami Warning Center issued the alert, saying that the first tsunami wave could strike the islands at 10:28 pm Hawaii Standard Time.
People living in coastal zones were told to move to higher ground until after 10:30 p.m.
(Reporting By Suzanne Roig; Writing by Peter Henderson; Editing by Andrew Osborn)
- Reuters
Monday, 27 August 2012
Tsunami in Other on Monday, 27 August, 2012 at 07:24 (07:24 AM) UTC.
Tsunami wave has been observed in DART 43413 buoy on 27.08.2012 at 06:19 UTC. The observed tsunami wave height was 0.1 feet (0.10 cm). The wave height wasn't dangerous.
- RSOE Edis
- RSOE Edis
Tsunami in Other on Monday, 27 August, 2012 at 07:24 (07:24 AM) UTC.
Tsunami wave has been observed in DART 43413 buoy on 27.08.2012 at 06:19 UTC. The observed tsunami wave height was 0.1 feet (0.10 cm). The wave height wasn't dangerous.
- RSOE Edis
- RSOE Edis
Wednesday, 9 May 2012
Ships Could Provide Better Tsunami Warnings
While in transit from Hawaii to Guam, the research vessel Kilo Moana detected the February 2010 Chilean tsunami. CREDIT: University of Hawaii, SOEST
As the research vessel Kilo Moana made its way from Hawaii to Guam in February 2010, Maule, Chile, was being struck by a magnitude-8.8 earthquake. Minutes later, a tsunami generated by that quake came ashore, devastating Chilean coastal towns and causing damage as far north as San Diego.
Although the waves were a mere 4 inches (9.4 centimeters) high out in the open ocean thousands of miles from the earthquake, scientists on the Kilo Moana detected the tsunami using the ship's geodetic GPS system.
Now researchers say that a network of commercial ships equipped with similar tools could improve tsunami warnings.
"Our discovery indicates that the vast fleet of commercial ships traveling the ocean each day could become a network of accurate tsunami sensors," said James Foster, a researcher at the University of Hawaii-Manoa.
Current tsunami warnings rely on details from a land-based network of tide gauges and a water-based system of deep ocean pressure sensors to determine where a tsunami is headed and how big it might be. Those systems are sparsely distributed and expensive to maintain. In fact, nearly 30 percent of the water-based system was down at the time of the Chilean quake, including the sensor nearest Hawaii.
Saddling commercial ships with GPS technology capable of measuring small tsunami waves would be relatively inexpensive, Foster said. His team estimates that this type of network would have been able to detect the 2010 Chile tsunami within an hour. Such warnings could potentially give residents more time to evacuate and save hundreds of lives.
"If we could equip some fraction of the shipping fleet with high-accuracy GPS and satellite communications, we could construct a dense, low-cost tsunami sensing network that would improve our detection and predictions of tsunamis — saving lives and money," Foster said.
The team will soon install the GPS tools on one or two ships to show that they can quickly and accurately detect small tsunami waves in the open ocean.
Foster's findings were published May 5 in the journal Geophysical Research Letters.
- OurAmazingPlanet
As the research vessel Kilo Moana made its way from Hawaii to Guam in February 2010, Maule, Chile, was being struck by a magnitude-8.8 earthquake. Minutes later, a tsunami generated by that quake came ashore, devastating Chilean coastal towns and causing damage as far north as San Diego.
Although the waves were a mere 4 inches (9.4 centimeters) high out in the open ocean thousands of miles from the earthquake, scientists on the Kilo Moana detected the tsunami using the ship's geodetic GPS system.
Now researchers say that a network of commercial ships equipped with similar tools could improve tsunami warnings.
"Our discovery indicates that the vast fleet of commercial ships traveling the ocean each day could become a network of accurate tsunami sensors," said James Foster, a researcher at the University of Hawaii-Manoa.
Current tsunami warnings rely on details from a land-based network of tide gauges and a water-based system of deep ocean pressure sensors to determine where a tsunami is headed and how big it might be. Those systems are sparsely distributed and expensive to maintain. In fact, nearly 30 percent of the water-based system was down at the time of the Chilean quake, including the sensor nearest Hawaii.
Saddling commercial ships with GPS technology capable of measuring small tsunami waves would be relatively inexpensive, Foster said. His team estimates that this type of network would have been able to detect the 2010 Chile tsunami within an hour. Such warnings could potentially give residents more time to evacuate and save hundreds of lives.
"If we could equip some fraction of the shipping fleet with high-accuracy GPS and satellite communications, we could construct a dense, low-cost tsunami sensing network that would improve our detection and predictions of tsunamis — saving lives and money," Foster said.
The team will soon install the GPS tools on one or two ships to show that they can quickly and accurately detect small tsunami waves in the open ocean.
Foster's findings were published May 5 in the journal Geophysical Research Letters.
- OurAmazingPlanet
Tuesday, 24 April 2012
Tsunami Scare Shows Gaps as Thousands Miss Quake Warnings
Khairil Razali thought a tire had blown out as his white Mitsubishi Strada pickup shuddered on the road as he drove to Banda Aceh on the northern tip of Indonesia’s Sumatra.
As he pulled over, the 34-year-old manager at the Indonesian Red Cross saw hordes of people racing out of houses and realized what was happening: an earthquake.
The 8.6-magnitude temblor and aftershocks in the Indian Ocean on April 11 and ensuing tsunami warnings brought back memories of the waves that ravaged the 12 countries and killed 220,000 people in 2004. While tsunami detection systems appear to have worked, the quake exposed flaws in the diffusion of warnings and effectiveness of evacuation plans, said officials including Sutopo Purwo Nugroho, head of Indonesia’s national disaster management agency’s data and information center.
“I saw people jump out from the second floor of their houses and rappelling down using ropes in panic,” Razali said in a phone interview. “Yells of ‘God is great’ were endless as they spilled into the streets, bringing back the 2004 trauma.”
Unlike the 2004 quake, the recent temblor didn’t create a lethal tsunami. Ten people died, including seven who had heart attacks, and 12 were injured, Nugroho said. The most severe structural damages were to a bridge, a prison and a dormitory school, he said.
Master Plan
Indonesian President Susilo Bambang Yudhoyono has ordered that a master plan be drawn up to rectify flaws and ensure lives are protected, pledging to fund the infrastructure needed to improve readiness. The country may spend 3 trillion rupiah ($327 million) to 5 trillion rupiah to add more shelters and tsunami detection devices in 2013 and 2014, Nugroho said.
Tsunami warnings by national authorities and the Pacific Tsunami Warning Center came minutes after the initial quake.
Preliminary information was sent within 10 minutes via short text messages to the disaster management agencies and media in Malaysia, advising the public to stay away from the beaches in the states of Perlis, Kedah, Penang and Perak, Yap Kok Seng, a director-general of Malaysia’s Meteorological Department, said in an e-mailed statement on April 16.
“We received the information from all international agencies such as in the U.S. and Japan immediately after the earthquake occurred,” Somsak Kaosuwan, director of Thailand’s National Disaster Warning Center, said in a phone interview the day after the quake.
Technology Reliance
Methods of spreading the warnings to people on the ground, including mass e-mails, short text messages to mobile phones, faxes and website postings, worked to varying degrees as telecommunications networks were overloaded, according to phone companies and government officials. The Jakarta-based Indonesian Meteorology, Climatology and Geophysics Agency also used its Twitter account to alert its 275,000 followers.
A surge in people seeking information online brought down official websites in Indonesia, Thailand and Malaysia.
“An overwhelming number of people tried to access our website to check for information, causing the website to crash for some time,” Thailand’s Kaosuwan said. “We will increase the capacity.”
The Indonesian meteorology agency plans to distribute quake information through other governmental websites after 400,000 visitors tried to access its website at the same time, shutting it down for hours, Prih Harjadi, the agency’s deputy of geophysics, said in a phone interview from Jakarta.
Silent Sirens
The Malaysian meteorological agency, which also experienced website issues, is working on ways to ensure “system availability during such episodes where network access traffic would increase drastically,” Yap said.
Wireless networks were clogged by the surge in calls, delaying or stopping short text messages, known as SMSs, from reaching people, according to Djarot Handoko, a spokesman for PT Indosat (ISAT), Indonesia’s second-largest mobile-phone company. Mobile traffic surged 75 percent after the earthquake, he said.
Some physical warning systems put in place after 2004, including sirens, failed to work properly. The only siren that blared in Banda Aceh had to be turned on manually after power was cut, Harjadi said.
Indonesia, with the world’s fourth-largest population, installed 34 early warning sirens across the nation, spanning 5,150 kilometers (3,200 miles), the distance from Florida to Alaska. Indonesia plans to have 1,000 sirens, Nugroho said. Of 25 tsunami buoys, only three operated correctly, he said.
Survival Instincts
Two power plants in Belawan and Banda Aceh were disrupted, with electricity completely restored about five hours after the quake, said Bambang Dwiyanto, a spokesman at PT Perusahaan Listrik Negara, the state-owned utility.
As warnings spread across the region and reached those at risk, survival instincts took over. Many ignored instructions to leave motorcycles or cars behind and to run for higher ground, clogging up roads and intersections. With motorists attempting to drive away from Banda Aceh, a city of 222,000, traffic ground to a halt and added to the potential casualties.
“We need more evacuation boards, routes, meeting points and training,” said Indonesia’s Nugroho, whose agency has recorded 1,712 tsunamis across the nation since 1629.
The agency is seeking the collaboration of local governments in providing emergency routes and taking care of signboards and shelters after some infrastructure was lost or stolen, Nugroho said.
Empty Shelters
In Thailand, most locals and foreigners at resorts followed evacuation orders according to plan, Thailand’s Kaosuwan said. “Yet there were people in some remote areas that failed to follow the instructions and guidelines. We have to educate them for future disasters.”
Thailand’s beach resorts of Phuket and Krabi were among the worst-hit tourist destinations in 2004.
A vertical shelter in Aceh with a capacity of 1,000 people was used by only 46 people, Nugroho said.
Such shelters include high-rise buildings, bridges and man- made hills. Padang, the capital of West Sumatra province, has seven of them. The city of 833,000 inhabitants would need 300 to 500 shelters, according to Nugroho.
Relief efforts in the 2004 tsunami were hampered by a lack of roads and communication in remote areas such as Aceh, which also suffered from conflict between the government and a rebel separatist movement at the time. The devastation paved the way for a peace agreement in 2005.
More evacuation drills must be performed, Razali of the Red Cross said.
Ring of Fire
Indonesia’s 18,000 islands sit along the Pacific’s “ring of fire” zone of active volcanoes and tectonic faults. Aceh, on the northern tip of Sumatra, is one of Indonesia’s poorest provinces, where 170,000 people died or went missing in the Indian Ocean tsunami in 2004.
A 6.8-magnitude earthquake struck off Indonesia’s West Papua in the morning of April 21.
President Yudhoyono has ordered the National Disaster Management Agency to design a master plan to anticipate disasters and expects to get a proposal within two months, Julian Aldrin Pasha, the presidential spokesman, said April 16.
“The Indonesian government will fund the infrastructure through the 2013 budget, while local governments should be responsible for maintenance,” the spokesman said.
The April 11 earthquake and tsunami panic soon turned to relief, as deadly waves never materialized, and warnings started coming down about four hours later.
Makeshift Megaphone
Where warning systems failed, people on the ground did what they could to spread the message.
The Red Cross’s Razali, when he realized a quake had struck, hurried to tune in to the citizen radio network called Radio Antar Penduduk Indonesia, the Indonesian Inter-Citizen Radio. Instinctively, he raised the radio’s volume, plugged it into his walkie-talkie, which Indonesians call handy-talkies or HTs, and hung it outside his window before resuming his journey to the city of Banda Aceh, driving the remaining 1.5 kilometers slowly.
“People were able to hear the latest information about a possible tsunami and aftershocks from our handy-talky,” Razali said.
- Bloomberg News
As he pulled over, the 34-year-old manager at the Indonesian Red Cross saw hordes of people racing out of houses and realized what was happening: an earthquake.
The 8.6-magnitude temblor and aftershocks in the Indian Ocean on April 11 and ensuing tsunami warnings brought back memories of the waves that ravaged the 12 countries and killed 220,000 people in 2004. While tsunami detection systems appear to have worked, the quake exposed flaws in the diffusion of warnings and effectiveness of evacuation plans, said officials including Sutopo Purwo Nugroho, head of Indonesia’s national disaster management agency’s data and information center.
“I saw people jump out from the second floor of their houses and rappelling down using ropes in panic,” Razali said in a phone interview. “Yells of ‘God is great’ were endless as they spilled into the streets, bringing back the 2004 trauma.”
Unlike the 2004 quake, the recent temblor didn’t create a lethal tsunami. Ten people died, including seven who had heart attacks, and 12 were injured, Nugroho said. The most severe structural damages were to a bridge, a prison and a dormitory school, he said.
Master Plan
Indonesian President Susilo Bambang Yudhoyono has ordered that a master plan be drawn up to rectify flaws and ensure lives are protected, pledging to fund the infrastructure needed to improve readiness. The country may spend 3 trillion rupiah ($327 million) to 5 trillion rupiah to add more shelters and tsunami detection devices in 2013 and 2014, Nugroho said.
Tsunami warnings by national authorities and the Pacific Tsunami Warning Center came minutes after the initial quake.
Preliminary information was sent within 10 minutes via short text messages to the disaster management agencies and media in Malaysia, advising the public to stay away from the beaches in the states of Perlis, Kedah, Penang and Perak, Yap Kok Seng, a director-general of Malaysia’s Meteorological Department, said in an e-mailed statement on April 16.
“We received the information from all international agencies such as in the U.S. and Japan immediately after the earthquake occurred,” Somsak Kaosuwan, director of Thailand’s National Disaster Warning Center, said in a phone interview the day after the quake.
Technology Reliance
Methods of spreading the warnings to people on the ground, including mass e-mails, short text messages to mobile phones, faxes and website postings, worked to varying degrees as telecommunications networks were overloaded, according to phone companies and government officials. The Jakarta-based Indonesian Meteorology, Climatology and Geophysics Agency also used its Twitter account to alert its 275,000 followers.
A surge in people seeking information online brought down official websites in Indonesia, Thailand and Malaysia.
“An overwhelming number of people tried to access our website to check for information, causing the website to crash for some time,” Thailand’s Kaosuwan said. “We will increase the capacity.”
The Indonesian meteorology agency plans to distribute quake information through other governmental websites after 400,000 visitors tried to access its website at the same time, shutting it down for hours, Prih Harjadi, the agency’s deputy of geophysics, said in a phone interview from Jakarta.
Silent Sirens
The Malaysian meteorological agency, which also experienced website issues, is working on ways to ensure “system availability during such episodes where network access traffic would increase drastically,” Yap said.
Wireless networks were clogged by the surge in calls, delaying or stopping short text messages, known as SMSs, from reaching people, according to Djarot Handoko, a spokesman for PT Indosat (ISAT), Indonesia’s second-largest mobile-phone company. Mobile traffic surged 75 percent after the earthquake, he said.
Some physical warning systems put in place after 2004, including sirens, failed to work properly. The only siren that blared in Banda Aceh had to be turned on manually after power was cut, Harjadi said.
Indonesia, with the world’s fourth-largest population, installed 34 early warning sirens across the nation, spanning 5,150 kilometers (3,200 miles), the distance from Florida to Alaska. Indonesia plans to have 1,000 sirens, Nugroho said. Of 25 tsunami buoys, only three operated correctly, he said.
Survival Instincts
Two power plants in Belawan and Banda Aceh were disrupted, with electricity completely restored about five hours after the quake, said Bambang Dwiyanto, a spokesman at PT Perusahaan Listrik Negara, the state-owned utility.
As warnings spread across the region and reached those at risk, survival instincts took over. Many ignored instructions to leave motorcycles or cars behind and to run for higher ground, clogging up roads and intersections. With motorists attempting to drive away from Banda Aceh, a city of 222,000, traffic ground to a halt and added to the potential casualties.
“We need more evacuation boards, routes, meeting points and training,” said Indonesia’s Nugroho, whose agency has recorded 1,712 tsunamis across the nation since 1629.
The agency is seeking the collaboration of local governments in providing emergency routes and taking care of signboards and shelters after some infrastructure was lost or stolen, Nugroho said.
Empty Shelters
In Thailand, most locals and foreigners at resorts followed evacuation orders according to plan, Thailand’s Kaosuwan said. “Yet there were people in some remote areas that failed to follow the instructions and guidelines. We have to educate them for future disasters.”
Thailand’s beach resorts of Phuket and Krabi were among the worst-hit tourist destinations in 2004.
A vertical shelter in Aceh with a capacity of 1,000 people was used by only 46 people, Nugroho said.
Such shelters include high-rise buildings, bridges and man- made hills. Padang, the capital of West Sumatra province, has seven of them. The city of 833,000 inhabitants would need 300 to 500 shelters, according to Nugroho.
Relief efforts in the 2004 tsunami were hampered by a lack of roads and communication in remote areas such as Aceh, which also suffered from conflict between the government and a rebel separatist movement at the time. The devastation paved the way for a peace agreement in 2005.
More evacuation drills must be performed, Razali of the Red Cross said.
Ring of Fire
Indonesia’s 18,000 islands sit along the Pacific’s “ring of fire” zone of active volcanoes and tectonic faults. Aceh, on the northern tip of Sumatra, is one of Indonesia’s poorest provinces, where 170,000 people died or went missing in the Indian Ocean tsunami in 2004.
A 6.8-magnitude earthquake struck off Indonesia’s West Papua in the morning of April 21.
President Yudhoyono has ordered the National Disaster Management Agency to design a master plan to anticipate disasters and expects to get a proposal within two months, Julian Aldrin Pasha, the presidential spokesman, said April 16.
“The Indonesian government will fund the infrastructure through the 2013 budget, while local governments should be responsible for maintenance,” the spokesman said.
The April 11 earthquake and tsunami panic soon turned to relief, as deadly waves never materialized, and warnings started coming down about four hours later.
Makeshift Megaphone
Where warning systems failed, people on the ground did what they could to spread the message.
The Red Cross’s Razali, when he realized a quake had struck, hurried to tune in to the citizen radio network called Radio Antar Penduduk Indonesia, the Indonesian Inter-Citizen Radio. Instinctively, he raised the radio’s volume, plugged it into his walkie-talkie, which Indonesians call handy-talkies or HTs, and hung it outside his window before resuming his journey to the city of Banda Aceh, driving the remaining 1.5 kilometers slowly.
“People were able to hear the latest information about a possible tsunami and aftershocks from our handy-talky,” Razali said.
- Bloomberg News
Friday, 13 April 2012
INTERVIEW-Indonesia quake a record, risks for Aceh grow
* Sumatra quake once-in-2,000-year event, says expert
* Increases stress on fault near Aceh
* A certainty more great quakes will hit Sumatra
By David Fogarty
SINGAPORE, April 13 (Reuters) - The powerful undersea earthquake off the Indonesian island of Sumatra this week was a once in 2,000 years event, and although it resulted in only a few deaths, it increases the risks of a killer quake in the region, a leading seismologist said.
Wednesday's 8.6 magnitude quake and a powerful aftershock were "strike-slip" quakes and the largest of that type recorded, Kerry Sieh, director of the Earth Observatory of Singapore, told Reuters.
"It's a really an exceptionally large and rare event," he said.
"Besides it being the biggest strike-slip earthquake ever recorded, the aftershock is the second biggest as far as we can tell," said Sieh, who has studied the seismically active, and deadly, fault zones around Sumatra for years.
Strike-slip quakes involve the horizontal movement of colliding earth plates, and are typically less powerful than those where there is vertical movement. They are also less likely to trigger big tsunamis, or tidal waves.
A magnitude 9.1 quake in roughly the same region on Boxing Day in 2004 decimated Aceh province on Sumatra and killed over 230,000 people in 13 countries around the Indian Ocean.
Sumatra, the westernmost island in the sprawling Indonesian archipelago, has a history of powerful quakes and tsunamis, most triggered by an offshore zone along its entire length, where the Indian-Australian tectonic plate is forced under the Eurasian plate.
This creates a deep ocean trench as one plate slides under the other at a rate of several centimetres a year. In this zone, called the Sunda megathrust, stress builds up when the subducting Indian-Australian plate bends the Eurasian plate like a spring board as it moves down into the Earth's crust.
Eventually enough stress builds up that the edge of Eurasian plate suddenly jolts upward, triggering an earthquake. The sudden uplift of the seafloor and huge pulse of seawater triggers a tsunami.
Over the centuries, repeated magnitude 8 and 9 quakes have struck along portions of the megathrust zone off the coast of Sumatra, flattening towns and killing thousands of people.
MORE QUAKES BREWING
Wednesday's event was different, Sieh said, because it occurred further west from the megathrust zone in a fault that runs north-south. This strike-slip fault involved a sudden horizontal movement of the Indian and Australian plates along hundreds of kilometres, preliminary data suggest.
Sieh said the Indian plate and Australian plate are moving relative to each other horizontally at about 1 cm a year.
"If all of that ... is taken up on this one fault and if you make some crude calculations about how much slip occurred during this earthquake, say 20 metres. It means that this earthquake shouldn't happen more than once every 2,000 years."
Wednesday's quake caused few casualties and triggered very small waves, despite its magnitude. But the main problem is that it likely to have increased stress on the plate boundaries near Aceh, increasing the risks of another major earthquake in the same area as the 2004 disaster.
In addition, research by Sieh and colleagues published in 2010 showed that the 2004 Aceh quake only relieved about half the stress that has built up over the centuries along a 400 km portion of the megathrust faultline.
That makes another major quake in the area a matter of time.
Adding to concerns, further south along another 700 km portion of the megathrust fault under the Mentawai islands, S ieh and colleagues in a separate 2008 research said so much stress was building up on this section that one or more major quakes were likely within years.
The Mentawai islands, a popular surfing destination, are a chain of about 70 islands off the western coast of Sumatra. They face the city of Padang on Sumatra, home to about one million people and likely to be in the path of any tsunami that is triggered.
"I am very confident that we are very likely to have within the next few decades to have this great Mentawai earthquake that will have a magnitude at least as big as yesterday's," said Sieh.
And when it does, history shows there will be more than one quake within a few years.
He said a magnitude 8.4 quake in 2007 that struck this part of the megathrust relieved only a small portion of the pent-up pressure. The last time it ruptured was a magnitude 9 quake in 1833 and an 8.4 quake in 1797.
"We've had so many big earthquakes around in Sumatra in the past few years that it seems like an awful lot of the faults around there seem ready to go."
- AlertNet
* Increases stress on fault near Aceh
* A certainty more great quakes will hit Sumatra
By David Fogarty
SINGAPORE, April 13 (Reuters) - The powerful undersea earthquake off the Indonesian island of Sumatra this week was a once in 2,000 years event, and although it resulted in only a few deaths, it increases the risks of a killer quake in the region, a leading seismologist said.
Wednesday's 8.6 magnitude quake and a powerful aftershock were "strike-slip" quakes and the largest of that type recorded, Kerry Sieh, director of the Earth Observatory of Singapore, told Reuters.
"It's a really an exceptionally large and rare event," he said.
"Besides it being the biggest strike-slip earthquake ever recorded, the aftershock is the second biggest as far as we can tell," said Sieh, who has studied the seismically active, and deadly, fault zones around Sumatra for years.
Strike-slip quakes involve the horizontal movement of colliding earth plates, and are typically less powerful than those where there is vertical movement. They are also less likely to trigger big tsunamis, or tidal waves.
A magnitude 9.1 quake in roughly the same region on Boxing Day in 2004 decimated Aceh province on Sumatra and killed over 230,000 people in 13 countries around the Indian Ocean.
Sumatra, the westernmost island in the sprawling Indonesian archipelago, has a history of powerful quakes and tsunamis, most triggered by an offshore zone along its entire length, where the Indian-Australian tectonic plate is forced under the Eurasian plate.
This creates a deep ocean trench as one plate slides under the other at a rate of several centimetres a year. In this zone, called the Sunda megathrust, stress builds up when the subducting Indian-Australian plate bends the Eurasian plate like a spring board as it moves down into the Earth's crust.
Eventually enough stress builds up that the edge of Eurasian plate suddenly jolts upward, triggering an earthquake. The sudden uplift of the seafloor and huge pulse of seawater triggers a tsunami.
Over the centuries, repeated magnitude 8 and 9 quakes have struck along portions of the megathrust zone off the coast of Sumatra, flattening towns and killing thousands of people.
MORE QUAKES BREWING
Wednesday's event was different, Sieh said, because it occurred further west from the megathrust zone in a fault that runs north-south. This strike-slip fault involved a sudden horizontal movement of the Indian and Australian plates along hundreds of kilometres, preliminary data suggest.
Sieh said the Indian plate and Australian plate are moving relative to each other horizontally at about 1 cm a year.
"If all of that ... is taken up on this one fault and if you make some crude calculations about how much slip occurred during this earthquake, say 20 metres. It means that this earthquake shouldn't happen more than once every 2,000 years."
Wednesday's quake caused few casualties and triggered very small waves, despite its magnitude. But the main problem is that it likely to have increased stress on the plate boundaries near Aceh, increasing the risks of another major earthquake in the same area as the 2004 disaster.
In addition, research by Sieh and colleagues published in 2010 showed that the 2004 Aceh quake only relieved about half the stress that has built up over the centuries along a 400 km portion of the megathrust faultline.
That makes another major quake in the area a matter of time.
Adding to concerns, further south along another 700 km portion of the megathrust fault under the Mentawai islands, S ieh and colleagues in a separate 2008 research said so much stress was building up on this section that one or more major quakes were likely within years.
The Mentawai islands, a popular surfing destination, are a chain of about 70 islands off the western coast of Sumatra. They face the city of Padang on Sumatra, home to about one million people and likely to be in the path of any tsunami that is triggered.
"I am very confident that we are very likely to have within the next few decades to have this great Mentawai earthquake that will have a magnitude at least as big as yesterday's," said Sieh.
And when it does, history shows there will be more than one quake within a few years.
He said a magnitude 8.4 quake in 2007 that struck this part of the megathrust relieved only a small portion of the pent-up pressure. The last time it ruptured was a magnitude 9 quake in 1833 and an 8.4 quake in 1797.
"We've had so many big earthquakes around in Sumatra in the past few years that it seems like an awful lot of the faults around there seem ready to go."
- AlertNet
Thursday, 12 April 2012
Tsunami scare tests new life-saving procedures
A 9.1-magnitude quake triggered a tsunami which killed nearly 230,000 people in southeast Asia in December 2004
But there's still work to be done -- not just in Indonesia, but in some other countries throughout the region as well.
Fears that Wednesday's 8.6-magnitude quake and resulting tsunami alert could bring a repeat of the 2004 disaster dissipated quickly as seismologists determined that Wednesday's events were very different and much less dangerous.
In the intervening hours, Indonesia put in place many of the procedures it has worked on for years, including some practiced at a drill witnessed by CNN in 2009.
"The lesson of 2004 is something that we're not going to repeat at this stage," vowed Teuku Faizasyah, a spokesman for the Indonesian president's office.
Speaking to CNN while evacuations were under way in parts of his country, he said the government was working "to bring confidence among the people that the government is with them."
Residents were being evacuated from some areas and encouraged to head to higher ground quickly, and authorities were trying to get information from remote areas, he said.
Later, the Pacific Tsunami Warning Center lifted a tsunami watch for the entire Indian Ocean, indicating the threat had passed.
No casualties or major damage was reported Wednesday from the quake and the 8.2-magnitude aftershock off the coast of Sumatra.
In 2004, a 9.1-magnitude quake triggered a tsunami that ultimately killed nearly 230,000 people in the region.
"In 2004, the quake was closer to the coast, stronger and was a different kind of earthquake," CNN meteorologist Dave Hennen said. "In 2004, the sea floor moved vertically, and this thrust displaced a lot of water, which produced the large tsunami. In this case, the plates moved more horizontally, and therefore a large tsunami was not generated."
"Even though the epicenters were only about 200 miles (about 320 kilometers) apart, they occurred on different tectonic plates," CNN meteorologist Brandon Miller added. "There are several plates that come together in this area, which is why it is so tectonically active. Today's quake occurred on the Indian plate, while the 2004 quake occurred on the Burma plate."
A 9.1-magnitude quake is 3.2 times larger, and more than 5 times stronger, than an 8.6-magnitude quake, CNN meteorologist Sean Morris said.
Tsunami warning sirens blared Wednesday in parts of Indonesia, and government authorities said warnings were also sent out to mobile phones and via churches and mosques.
"Governments are more prepared," CNN weather anchor Mari Ramos said. "There are sirens in place along coastal communities. There are buoys in the ocean to measure water level changes. There is better communication among government agencies, countries and the media. The word gets out much more quickly, and that helps saves lives."
However, "the number of measuring devices in the Indian Ocean is tiny compared to the Pacific. It's a start, but more are needed."
In October 2009, CNN's Dan Rivers visited the devastated Aceh region. He watched a well-organized tsunami drill, complete with droning alarms and people covered in fake blood fleeing from an imaginary wave.
Authorities have built tsunami shelters that are raised high and can hold several hundred people, he said. Escape routes are marked.
While it was not immediately clear how many people headed to higher ground Wednesday, some videos from the region showed people apparently leaving low-lying areas.
That speaks to another important change from 2004: People are more aware of the danger.
Back then, "there was nothing," Rivers said. "No one really knew what to do, no one even knew what a tsunami was."
Now, Ramos adds, "Overall, the general population is much more aware."
The need for that awareness applies to citizens of other countries as well, said Walter Braunohler, a spokesman for the U.S. Embassy in Thailand.
"Sadly, we did learn a lot of lessons from that (2004) natural disaster," he said Wednesday. "And one of the biggest ones is that people should really keep in touch with their embassy."
Other countries in the region also reacted quickly to Wednesday's tsunami threat.
Thailand issued an evacuation order for everyone along the Andaman coast Wednesday, according to state-run news agency MCOT.
In the Maldives, some resorts were evacuated as a precaution, according to CNN's Erin Burnett, who was on vacation in the islands.
But, she said, "what strikes me most is essentially the lack of a warning system" in the Maldives. Officials rely primarily on information from the U.S. Geological Survey, she said.
That speaks to the problem the region still faces, Ramos said. "The fact that the Maldives were included in the (warning center) bulletin is an improvement from 2004. But there's still a long way to go."
- CNN
Men who predicted in 6 mintues that there was no tsunami threat
Their soldiers stand guard along the northern and western borders with fingers well trenched on the triggers of sophisticated rifles. But the Indian scientists ensure the safety of Pakistan from natural disasters like tsunamis and cyclones!
It may sound unbelievable to ordinary mortals but the truth is that the tsunami buoys and bottom pressure recorders developed by the scientists of Indian National Centre for Ocean Information Services (INCOIS), Hyderabad and the National Institute of Ocean Technology (NIOT), Chennai, protect all countries along the Indian Ocean Rim including Pakistan from the fury of the nature.
The tsunami buoys and bottom pressure recorders installed in the Arabian Sea (some 400 km off Mumbai Coast), Bay of Bengal and Indian Ocean provide scientists of the Indian Tsunami Early Warning Centre at Hyderabad with real time data about the characteristics of the seas on round-the-clock basis.
“Any abnormalities noticed from the Coast of Makran adjoining Pakistan to the Malacca Straits are analysed by the scientists of the ITEWC, and the results are conveyed to the National Disaster Management Authority of the countries concerned. They will get nearly 20 minutes to launch the rescue and evacuation measures in the eventuality of a tsunami,” Dr Satish Shenoi, director, INCOIS, told DNA.
Dr Srinivas Kumar, head of ITEWC, Hyderabad, said his centre was in contact with all the tsunami monitoring centres along the Indian Ocean. “This help us to pick up any abnormalities in the seas ranging from Gulf of Malaca to the Makran Coast and detect the possibilities of a tsunami within seconds. All countries along the Indian Ocean Rim depend on us for early warningon tsunamis and cyclones originating in this region,” said Dr Kumar.
The bottom pressure recorders and buoys detect sea surface and bottom temperature, pressure, wind speed and direction and transfer the data in a flash of a second to the ITEWC. “These data are sufficient for us to find out whether the earthquake happening in the bottom of the ocean is tsunamigenic or not,” said Dr Shenoi.
Dr Shenoi said Wednesday’s earthquake near Sumatra was picked up by the ITEWC scientists at 2:08 pm. “Within six minutes we alerted all the countries along the Indian Ocean Rim. And my scientists could make out within minutes that the earthquake was not tsunamigenic and we accordingly informed the NDMA,” he said.
Interestingly, it was INCOIS which gave advance warning about Cyclone Thane which struck the East Coast in December 2011. “Not a single fisherman lost his life because they did not venture out into the sea because of our warning. Well, we could not prevent the trees from getting uprooted due to the cyclone. But we literally tamed Thane through our sharp forecast,” said a senior INCOIS scientist.
- DNA
It may sound unbelievable to ordinary mortals but the truth is that the tsunami buoys and bottom pressure recorders developed by the scientists of Indian National Centre for Ocean Information Services (INCOIS), Hyderabad and the National Institute of Ocean Technology (NIOT), Chennai, protect all countries along the Indian Ocean Rim including Pakistan from the fury of the nature.
The tsunami buoys and bottom pressure recorders installed in the Arabian Sea (some 400 km off Mumbai Coast), Bay of Bengal and Indian Ocean provide scientists of the Indian Tsunami Early Warning Centre at Hyderabad with real time data about the characteristics of the seas on round-the-clock basis.
“Any abnormalities noticed from the Coast of Makran adjoining Pakistan to the Malacca Straits are analysed by the scientists of the ITEWC, and the results are conveyed to the National Disaster Management Authority of the countries concerned. They will get nearly 20 minutes to launch the rescue and evacuation measures in the eventuality of a tsunami,” Dr Satish Shenoi, director, INCOIS, told DNA.
Dr Srinivas Kumar, head of ITEWC, Hyderabad, said his centre was in contact with all the tsunami monitoring centres along the Indian Ocean. “This help us to pick up any abnormalities in the seas ranging from Gulf of Malaca to the Makran Coast and detect the possibilities of a tsunami within seconds. All countries along the Indian Ocean Rim depend on us for early warningon tsunamis and cyclones originating in this region,” said Dr Kumar.
The bottom pressure recorders and buoys detect sea surface and bottom temperature, pressure, wind speed and direction and transfer the data in a flash of a second to the ITEWC. “These data are sufficient for us to find out whether the earthquake happening in the bottom of the ocean is tsunamigenic or not,” said Dr Shenoi.
Dr Shenoi said Wednesday’s earthquake near Sumatra was picked up by the ITEWC scientists at 2:08 pm. “Within six minutes we alerted all the countries along the Indian Ocean Rim. And my scientists could make out within minutes that the earthquake was not tsunamigenic and we accordingly informed the NDMA,” he said.
Interestingly, it was INCOIS which gave advance warning about Cyclone Thane which struck the East Coast in December 2011. “Not a single fisherman lost his life because they did not venture out into the sea because of our warning. Well, we could not prevent the trees from getting uprooted due to the cyclone. But we literally tamed Thane through our sharp forecast,” said a senior INCOIS scientist.
- DNA
Indian Ocean tsunami early warning systems pass test
Image: Indian Ocean tsunami early warning system was designed to combine data from underwater probes, orbiting global positioning system satellites, and floating buoys, to better detect a coming tidal wave.
By David Singh
GENEVA, 11 April 2012 - Following a massive earthquake earlier today in the Indian Ocean and the threat of a tsunami, Indonesian President and UNISDR Global Disaster Risk Reduction Champion, Susilo Bambang Yudhyono, told the press, "Our early warning system is working well". There were no tsunamis in Banda Aceh or other places which were hard hit by the 2004 Indian Ocean tsunami.
The 8.6 magnitude earthquake occurred at 8.38 UTC, 437 km southwest of Banda Aceh in Indonesia and 33 km beneath the ocean floor, prompting a tsunami watch to be immediately issued for Australia, Bangladesh, Comoros, Crozet Islands, Diego Garcia, India, Indonesia, Iran, Kenya, Kerguelen Islands, Madagascar, Malaysia, Maldives, Mauritius, Mozambique, Myanmar, Oman, Pakistan, Reunion, Seychelles, Singapore, Sri Lanka, Somalia, South Africa, Tanzania, Thailand, United Arab Emirates and Yemen.
Despite initial panic by people in many at-risk locations when they thought they would experience a repeat of the devastating 2004 Indian Ocean Tsunami which swept through many of the same areas on tsunami watch today, early warning systems and evacuation drills today appear to have demonstrated their usefulness.
"This quake released less energy than the 9.1 magnitude 2004 earthquake which was roughly in the same location", observed Jerry Velasquez, Head of the UNISDR Asia-Pacific Office.
"The destruction in 2004 was linked to the tsunami generated by the shifting of tectonic plates. There are many variations of tectonic shifting that cause earthquakes. Some plates are displaced vertically, while others are displaced horizontally. In general, the vertical displacement of plates is more likely to generate tsunamis. Fortunately this quake was caused by tectonic plates that shifted horizontally," said Velasquez.
Confirming that people in Banda Aceh were able to evacuate to safe areas, President Yudhoyono told reporters, "There are no casualties or major damage reported, but we remain vigilant. I have ordered the national relief team to fly immediately to Aceh to ensure the situation is under control and to take any necessary action."
According to Thorkild Aarup, Head of the Tsunami Unit of the UN Intergovernmental Oceanographic Commission (IOC), "The three early warning systems functioned as they should have across the board. The Indonesian early warning was issued at 8.43 UTC - five minutes after the quake happened. The Australian warning was issued 10 minutes after, while India's was issued eight minutes after the earthquake."
In the aftermath of the 2004 the IOC (comprising UNESCO and other partners) began coordinating efforts to create an Indian Ocean tsunami early warning system. An interim system was established in 2005 which culminated with the establishment of the three early warning providers this year -- Australia, India and Indonesia.
Today there is a large network of seismographic centres, national warning centres, agencies, coastal and deep-ocean stations in place across the Indian Ocean to detect potential tsunamis and pass on warnings to communities.
Gaps remain in the system - most significantly at the community level - and experts say more coordination is needed to ensure national centres are communicating with each other and sharing information across the region.
"Yes there are gaps," said Aaarup, "But the Indian Ocean is much better prepared than it was in 2004. The tsunami early warning systems are like the atmospheric systems used by meteorologists which are constantly being improved by new technology. The same is true for the tsunami warning systems".
According to news reports tsunami warning sirens were heard in Phuket where people were observed to be calmly following evacuation routes to safe zones. Authorities shut down the international airport, hotel guests in the resort area were evacuated to the hills behind while local people were seen heading for higher ground in cars and on motorcycles.
People near the coast in six Thai provinces were ordered to move to higher ground. In the city of Medan, a hospital evacuated patients, who were wheeled out on beds and in wheelchairs. In southern India, hundreds of office workers in the city of Bangalore left their buildings while the port of Chennai closed down because of tsunami fears.
- United Nations International Strategy for Disaster Reduction Secretariat - Asia and Pacific (UNISDR AP)
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