Big quake rattles Sumatra west coast

Apriadi Gunawan, The Jakarta Post, Medan

An employee at the North Sumatra provincial administration, Asbin, ran down the stairs from his office on the third floor shouting "earthquake... earthquake... hurry down!"

His calls prompted the other five employees in the room to leave with him, jumping down the stairs until they were outside.

Soon, all of the public servants had gathered outside the eight-story building. Many said the tremor had initially made them feel queasy.

"When the quake hit, I was writing but suddenly I felt dizzy. I didn't know it was because of the earthquake until someone shouted. They all ran downstairs, and so did I," recalled an employee, Erni.

A 6.8-magnitude undersea earthquake centered off the west coast of Sumatra hit on Thursday morning, disrupting activities of various offices in Medan city and Nias Island as the workers spilled out of their office buildings in panic.

In Medan, activity returned to normal about an hour after the quake, however many workers in Nias Island went home, fearing more powerful aftershocks.

The Meteorological and Geophysics Agency (BMG) in Medan said the quake hit at 8:45 a.m. An analyst, Sunardi, said the epicenter was located 30 kilometers under the sea in waters off Nias Island, or around 111 km southwest of Gunung Sitoli city in Nias regency.

Sunardi said the quake was strongly felt in Nias and several areas in North Sumatra, including Sibolga and Medan.

"In Nias Island, the tremor could reach 4 to 5 MMI (Modified Mercalli Intensity), meaning it could destroy objects in its surroundings," Sunardi said.

Nias deputy regent Agus Mendrofa said there were as yet no reports of any damage caused by the Thursday's quake, which was strongly felt on the island and lasted for about 30 seconds.

Some residents panicked and had already fled to higher grounds in fear of tsunamis and stronger aftershocks, he said.

"When the quake hit, I happened to be in an official residence in Gunung Sitoli, talking to a quake expert Teddy Boen. We felt strong and long tremors," Agus told The Jakarta Post by phone on Thursday.

He said the expert had been invited especially to provide information about earthquakes to residents following many aftershocks that have rocked the island since an 8.7-level quake killed hundreds of people there in March.

"The residents here need to know more about earthquakes to prevent trauma, especially at the time when we are experiencing many aftershocks," Agus said.

The Thursday earthquake was the second big tremor this week, after another offshore quake, this time measuring 6.9 in magnitude, rocked the west coast of Sumatra on Saturday.

The largest of the recent movements, a massive 9.3 Richter scale movement, triggered a tsunami that hit Aceh and North Sumatra five months ago, killing up to 130,000 people there. Another 8.7-magnitude quake devastated parts of the west coast of Sumatra in March, with Nias Island being the worst hit.