The hard lessons learned from the 2004 tsunami were put to the test as thousands of residents and tourists all along the Andaman coast rushed to higher ground following yesterday's 8.6-magnitude earthquake off Indonesia.
Tsunami alarms and warnings sounded across the region following the huge earthquake at 3.38pm Bangkok time. The US Geological Survey said the earthquake was centred 431km off the city of Banda Aceh, and was followed two hours later by an 8.2-magnitude underseas quake.
The tremors, which were felt by office workers in Bangkok, prompted authorities in Thailand, Indonesia, India, Malaysia and other countries around the Indian Ocean to issue evacuation warnings.
Thai authorities sounded alarms in six provinces _ Phuket, Krabi, Phangnga, Ranong, Satun and Trang. The alert was cancelled several hours later, with no reports of damage or casualties made although small waves 10cm high were reported off Phangnga.
Somsak Khaosuwan, director of the National Disaster Warning Centre, called off the tsunami warnings at 7.30pm.
"The highest waves from the first quake were recorded at 10 centimetres at Ko Miang in Phangnga, followed by a wave of 30cm from the second quake," he said, adding that no damage or impact from the quake was expected.
"The centre will remain on watch for another 24 hours. But residents may return to their homes."
Mr Somsak's announcement was followed by a taped television address from Prime Minister Yingluck Shinawatra urging the public to continue to exercise caution about potential aftershocks.
"The warning system and evacuation has gone smoothly. The public should continue to monitor developments until the National Disaster Warning Centre eases its alert," she said in a televised address around 8pm.
Most businesses are expected to resume operations today. Phuket international airport reopened last night following a four-hour closure. Other businesses, which largely closed early as staff moved to evacuation centres, are expected to reopen today.
At Phuket Fantasia, executive vice-president Litti Kewkacha said more than 1,000 staff were relocated from the entertainment park to a company retreat.
"After our experiences with the 2004 tsunami, we prepared a safehouse for our staff just in case," he said.
Even in Bangkok, the earthquake and initial tsunami warnings prompted a number of companies to close early following reports of swaying buildings, and parliament cut short its debate on a government plan to amend the charter.
Prime Minister Yingluck Shinawatra speaks to the nation: "The warning system and evacuation has gone smoothly. The public should continue to monitor developments until the National Disaster Warning Centre eases its alert."
Taloengsak Phuwayanpong, an official at Krabi's natural disaster prevention centre, said provincial governor Prasit Osathanont instructed officials along the coast to sound a warning as soon as the earthquake struck.
"The people were told to evacuate to safe areas. There was no need to wait for an official warning," he said, adding that the tremors were felt in buildings across the province.
Somporn Phakdi, a businessman on Phi Phi Island, said island residents moved quickly to the evacuation centres as soon as the earthquake was felt.
"We've learned our lesson. When we hear about an earthquake, we take precautions and seek shelter on high ground, whether or not there is a chance of a tsunami," he said.
One tourist, Kittisak Charoenpanich, said he felt quite panicky and alarmed after the staff at his hotel in Krabi called for an evacuation.
"I remember watching the TV during the [2004 tsunami], and seeing videos of the big waves and how frightening it all was," he said.
Mr Kittisak, aged 40, said he was visiting Krabi to attend a reunion party of alumni of Prince of Songkla University.
"We had planned to hold the party on the beach. But after the warning, we moved the party to the hotel," he said.
The 2004 Boxing Day tsunami killed more than 230,000 people in 15 countries across the region, including an estimated 8,200 deaths in Thailand.
In Aceh, Indonesia, the epicentre of the 2004 tsunami, residents yesterday fled in panic in attempts to move inland and to higher ground.
Others made no attempt at evacuation, and instead gathered at nearby mosques and schools to pray for the best.
"We ran as fast as we could," Banda Aceh resident Marhamah told dpa. "People cried, some running to the hills, while some men went to the mosque to recite prayers."
An expert with the British Geological Survey said the tsunamis were small because the quakes' movement was horizontal, not vertical, and caused no drop in the sea floor, which is what triggers tsunamis.
"Although an earthquake of this magnitude has the potential to cause a large tsunami ... we haven't seen any drop of the sea floor, which is what generates the wave," seismologist Susanne Sargeant told AFP.