Earthquake Journal Entry

Another Big Quake Jolts Sumatra (March 29, 2005)

Another huge earthquake jolted northwestern Indonesia this week. The powerful magnitude 8.7 tremor struck along the Sunda Trench near the coast of Sumatra.

Its epicenter was about 200 miles (320 kilometers) south of where the massive December 26th quake struck.

This week's quake touched off widespread panic that a tsunami would follow. But only small waves hit the Sumatra coast. Shaking was felt across northern Sumatra and as far away as Kuala Lampar, the capital of Malaysia. News of the quake spread quickly across the region. People living along the coasts of Sri Lanka and India were urged to find higher ground.

This week's quake wasn't nearly as destructive as the one on December 26th. The one big exception is the Indonesian island of Nias, a popular surfing area close to the epicenter. Early reports say at least 300 were killed but the toll could climb to between 1,000 and 2,000 victims.

Scientists recently predicted the Sunda Trench was ripe for another tremor. The Australian plate subducts or dives beneath the Sunda plate along this trench. The researchers calculated the December 26th quake had increased stress on the nearby section of the trench and raised the risk of another big quake.

Quake experts are puzzled about why there was no big tsunami this time. Tsunamis are generated when the ocean floor moves up and down during an earthquake. Scientists predicted the Sumatra coast would be hit again if another big tremor struck. There are signs the quake did trigger waves that moved southwest from the epicenter towards the open sea and away from heavily populated Sumatra.