Reuters
Banda Aceh, April 11, 2012
Banda Aceh, April 11, 2012
Acehnese women hug each other and pray shortly after the quake. AFP/Chaideer Mahyuddin
A powerful 8.6 magnitude earthquake and a series of strong aftershocks struck off Indonesia on Wednesday, sending people scurrying from buildings as far away as southern India, but there seemed little risk of a disastrous tsunami as in 2004.
India withdrew a national tsunami
India withdrew a national tsunami
alert issued after huge earthquakes struck off Indonesia on Wednesday, the Indian tsunami warning centre said.
"Thankfully, the danger has passed," a scientist at the centre told Reuters.
Disaster officials had earlier warned waves as high as 3.9 meters could hit parts of Andoman and Nicobar islands.
A few thousand people were evacuated from the more vulnerable islands, a police official said.
Indonesia said it was checking for damage and casualties but remarkably, no such reports had been received for several hours after the quakes, including in Aceh, the closest province and the area decimated by the disaster eight years ago.
However, some areas close to the epicentre are remote so it could take some time to find out if there was any damage.
Many people were frightened of further tremors.
"It's dark out here but I am scared to go home," said Mila, a 41-year-old woman taking refuge in the grand mosque in the town of Banda Aceh, the provincial capital.
"I just want to stay alert because I fear there will be more quakes coming. We are human, it is only natural that we have fear, but I really wish we will all be safe."
Waves of up to one metre (3.3 feet) high were seen near islands off Aceh, but Indonesia cancelled a warning for fresh tsunamis. It said the worst-hit area was the thinly populated island of Simeulue, off Aceh's southern coast.
The first quake struck at 0838 GMT and an 8.2 magnitude aftershock just over two hours later, at 1043 GMT. Two more strong aftershocks hit later.
The Hawaii-based Pacific Tsunami Warning Center also withdrew tsunami warnings for the entire Indian Ocean after keeping them in force for several hours.
"Level readings now indicate that the threat has diminished or is over for most areas," the agency's bulletin said.
Thailand and India also withdrew tsunami warnings.
Thailand, Indonesia, Sri Lanka and India were all badly hit in 2004. At least 230,000 people in 13 Indian Ocean countries were killed in the Boxing Day disaster that year, including 170,000 in and around Aceh alone.
Last year, an earthquake and tsunami off Japan's northeastern coast killed at least 23,000 people and triggered the world's worst nuclear crisis in 25 years after waves battered a nuclear power station.
On Wednesday, people near the coast in six Thai provinces were ordered to move to higher ground. Authorities shut down the international airport in the Thai beach resort province of Phuket.
The quakes were about 300 miles (500 km) southwest of Banda Aceh, on the northern tip of Indonesia's Sumatra island, the US Geological survey said. The first was at a depth of 20.5 miles (33 km).
Indonesia's disaster management agency said power failed in Aceh province and people were gathering on high
ground as sirens warned of the danger.
ground as sirens warned of the danger.
"The electricity is down, there are traffic jams to access higher ground. Sirens and Koran recitals from mosques are everywhere," said Sutopo, spokesman for the agency.
"The warning system worked," Indonesian President Susilo Bambang Yudhoyono said.
Warning sirens also rang out across the Thai island of Phuket, a tourist hotspot that was one of the worst hit areas in the 2004 tsunami.
"Guests from expensive hotels overlooking Phuket's beaches were evacuated to the hills behind and local people were driving away in cars and on motorcycles. Everyone seemed quite calm, the warning had been issued well in advance," freelance journalist Apichai Thonoy told Reuters by telephone.
Out on the streets
Indonesian television showed people gathering in mosques in Banda Aceh. Many others were on the streets, holding crying children.
Indonesian television showed people gathering in mosques in Banda Aceh. Many others were on the streets, holding crying children.
In the city of Medan, a hospital evacuated patients, who were wheeled out on beds and in wheelchairs.
Wednesday's quakes were felt as far away as the Thai capital, Bangkok, and 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.
The quakes were in roughly in the same area as the 2004 quake, which was at a depth of 18 miles (30 km) along a fault line running under the Indian Ocean, off western Indonesia and up into the Bay of Bengal.
Experts said Wednesday quakes were a "strike-slip" fault, meaning a more horizontal shift of the ground under the sea as opposed to a sudden vertical shift, and less risk of a large displacement of water triggering a tsunami.
"The nature of the sideways rupture and sideways movement is not predisposed to cause a bad tsunami, so almost certainly, the crisis has been avoided," said David Rothery, an expert at the Open University in the UK
The quakes were also felt in Sri Lanka, where office workers in the capital, Colombo, fled their offices.
Mahinda Amaraweera, Sri Lanka's minister for disaster management, called for calm while advising people near the coast to seek safety.
"I urge the people not to panic. We have time if there is a tsunami going to come. So please evacuate if you are in the coastal area and move to safer places," Amaraweera told a private television channel.
In Bangladesh, where two tremors were felt, authorities said there appeared to be no threat of a tsunami.
Indonesia Quake Gave Tsunami Alarms a Trial Run
ردحذفBy ERIC BELLMAN
JAKARTA—The expensive warning systems built to protect people from tsunamis sweeping across the Indian Ocean did what they were designed to do following massive earthquakes in Indonesia Wednesday, but that doesn't mean major casualties could have been avoided had the quakes triggered a killer wave, disaster experts say.
The magnitude 8.6 quake near Indonesia's easternmost province of Aceh—the region that was the source of the 2004 tsunami that killed more than 230,000 people—didn't spawn a deadly wave this time. But it did set off alarms across the globe thanks to an early-tsunami-warning system that has cost more than $100 million to build. Within minutes of the quake, people from Indonesia to Africa were told to get away from the water as there was a chance of another destructive tsunami.
While tourists at Thailand's beach resorts and people near the beaches of India and Sri Lanka were given enough warning to move to higher ground, Indonesians near the epicenter might not have made it if they had waited for official warnings to head uphill, said Costas Synolakis, professor of civil engineering and director of the Tsunami Research Center at the University of Southern California.
Depending on the location of the quake, deadly waves could land on population centers in Aceh in as little as 15 minutes after an earthquake, he said.
"It worked better this time. There were alerts and people evacuated," he said. "But in Aceh there is never going to be enough time to evacuate [the coast] after big earthquakes. We were lucky this time it was a [less violent] horizontal motion, so it didn't generate a big tsunami."
In 2004, most communities hit by the waves were never warned despite the hours it took for the tsunami to hit in some places farther from the epicenter in Indonesia. Even if they had been warned, they may not have known to head toward higher ground. Since then, the countries worst affected have used tax money and some of the billions of dollars in international aid that came after the disaster to upgrade their tsunami-detection and preparation systems.
Today, a network of tsunami sensors and sirens stretches from the beaches of Bali in Indonesia through to the coast of Colombo in Sri Lanka and beyond. When a quake is big enough to give birth to a tsunami, it automatically triggers alarms and notifications through community loudspeaker systems and cellphones as well as on radio and television broadcasts.
—Shibani Mahtani
and Yayu Yuniar
contributed to this article.
Source:
http://online.wsj.com/article/SB10001424052702303624004577341343834082570.html?mod=googlenews_wsj
There have also been awareness campaigns, with evacuation signs and maps posted in coastal communities, to teach people what to do and where to go in the event of a tsunami alert. Similar campaigns and collection points that have been in place in Japan for decades saved the lives of tens of thousands of people when much of its Northeastern coast was flattened by waves last year.
ردحذفWhile close to 90% of the residents of Aceh neighborhoods hit directly by the 2004 tsunami were killed, only around 10% of Japanese residents of the worst-hit areas died in the waves, Mr. Synolakis said, as they started moving away from the water immediately after feeling a big quake. "This is the example Indonesia should follow when you feel a strong earthquake. Don't wait for a warning, you have to evacuate right away," he said.
With no deadly waves to truly test the systems this time, it is difficult to assess them, but government authorities managing them said they were happy with the results this week. More often than not, people were warned and evacuated to the proper locations.
"The early-warning system worked well as people are more experienced now thanks to regular drills," said Suharjono, the head of the Indonesian Meteorology and Geophysics Agency's earthquake center in Jakarta, who like many Indonesians goes by only one name. "We've learned a lot since the 2004 tsunami."
In Thailand, people were warned though loudspeakers along the beach as well as sound trucks that went up and down streets in exposed neighborhoods to get the word out. It used text messages as well as social media to warn people. Its beach-resort hotel staff used their training on how to get their guests to safety.
"This system demonstrated its effectiveness in the rapid way that tourists all along the Andaman Sea coast were relocated to safety zones when the tsunami warning was put into effect," said Suraphon Svetasreni, governor of the Tourism Authority of Thailand on Friday.
People on the ground said that while they had received some training and heard sirens, they were mostly motivated by their memories. With more than 170,000 killed in Aceh alone, there were few families unaffected by the 2004 tsunami.
People in the Aceh capital of Banda Aceh started moving well before the warning sirens went off, witnesses say. Civil servant Fadhli Haji Abdullah said people scrambled to higher ground, clogging the roads, immediately after the earthquakes stopped. He remembered training sessions from the government and watched the ocean for abnormal movements after the earthquake but many people had forgotten their training and were panicking, he said.
"We were trained and practiced with drills but still it got a bit crazy," he said. "When the sirens started it only created more panic."