Indonesian quakes trigger tsunami; quirk of nature sends worst to sea

~ Almost all the quakes were less than 120 miles from the shore and around 12 miles deep.

PADANG, Indonesia -- The ground shook so hard Yulinar had to grab a table to steady herself. Minutes later, she heard a warning crackling over the speakers of the neighborhood mosque -- a tsunami could crash into her fishing village on Indonesia's Sumatra island at any minute.

But despite the intensity of the shallow undersea earthquake, no waves lashed the beach and the family shack was undamaged. A quirk of nature sent the full force of the tsunami out to sea, preventing a repeat of the 2004 Indian Ocean disaster that killed more than 230,000 people -- most of them on Sumatra.

"We heard the mayor's voice and then ran up a hill," said Yulinar, a mother of five, of the 8.4-magnitude quake that shook Indonesia on Wednesday. "It was very bad. I was so scared a tsunami was coming."

A series of powerful earthquakes and aftershocks followed over a 24-hour period Wednesday and Thursday, damaging hundreds of homes, mosques and schools, and unleashing a 10-foot-high tsunami. At least 10 people were killed.

But the huge mass of water spawned by the initial 8.4-magnitude quake was pushed to sea rather than land, said Mike Turnbull, a seismologist at Australia's Central Queensland University.

"It could have quite easily have been the other way," he said, noting that pressure between the shifting Australian, Indian and Asian plates has been building up over hundreds of thousands of years and was ready to explode. "It's a quirk of nature that this is how it happened."

Though the 10-foot-high tsunami slammed into at least one fishing village on Sumatra on Wednesday, damage was not severe.

Still, Rukhlan, a 43-year-old angler, said residents in Muara Maras were horrified when they saw the ocean retreat and then race back to shore.

"I heard people screaming and yelling, 'Tsunami! tsunami!"' he said. "I ran to find my children, but they had already gone to the hills."

A 65-year-old woman, Asiah, felt weak when the earth started moving beneath her.

"I was having difficulty breathing or walking," she said. "I was afraid. My son grabbed hold of me and carried me out of the house. All I could do was pray."

A dozen houses were swept out to sea. Smaller waves were recorded farther down the coast.

Two other powerful temblors -- magnitudes 7.8 and 7.1 -- followed Thursday off Sumatra and two weaker quakes were felt later, the U.S. Geological Survey said. Several tsunami warnings were issued and later lifted.

The worst destruction was caused by the jolts along the coast, especially in the Sumatran city of Padang. Almost all the quakes were less than 120 miles from the shore and around 12 miles deep.

"At least five large buildings -- including mosques, houses and a school -- collapsed," said Surya Budhi, who was overseeing emergency response in the area, and rescuers were searching for survivors at a badly damaged car dealership.

A fire also broke out on the fourth floor of a shopping mall.

The magnitude-7.8 quake struck at 6:49 a.m. Thursday and was followed by a 7.1 quake at 10:35 a.m., and then two of 6.2 later in the day.

More than 30 aftershocks have rattled the region in the last day and many people refused to return to their homes, fearing a repeat of the 2004 tsunami. Nearly two-thirds of the deaths in that disaster were in Aceh province.

Hundreds of residents spent Thursday night sleeping in parks or on sidewalks.

Telephone lines and electricity were disrupted across a large swath of Indonesia, making it difficult to get information about damage and casualties.

Death tolls released by several agencies ranged from five to 10. Rustam Pakaya, the chief of Health Crisis Center, gave the latter figure, which was based on information gathered from local hospitals, clinics and regional health offices. He said at least 49 people were injured.

Sensitive to criticism about slow responses to the 2004 tsunami triggered by a magnitude-9 quake, governments issued alerts as far away as Kenya and Tanzania in East Africa, telling people to leave beaches. People in Mombasa, Kenya, crowded into buses after hearing the warning over the radio.

Thailand's National Disaster Warning Center sent cell phone text messages alerting hundreds of officials in six southern provinces, and authorities also were told to prepare in India's remote Andaman and Nicobar islands.

Sri Lankans were told to move at least 650 feet inland.

Indonesia, the world's largest archipelago, with a population of 235 million people, is prone to seismic upheaval due to its location on the "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin.