EarthQuakes In Sumatra-Indonesia

KOMPAS.com - A string of natural disasters like tectonic earthquakes with strong and low magnitude have struck Indonesia in the last two days.

The tectonic quakes which shook three provinces in Indonesia occurred on Wednesday (Sept 30) and Thursday (Oct 1). A strong earthquake came from West Sumatra in a temblor measuring 7.6 on the Richter scale rocking this region at 5.16 pm West Indonesian Standard Time.

Latest finds showed that the earthquake in West Sumatra had killed 478 people and injured over 3,000, Esti of the Meterology, Climatology and Geophysics Agency said Wednesday. Many of victims were trapped in the rubbles of collapsed and damaged buildings, and rescue team members were still working hard to find and rescue victims.

Esti said that the epicenter of the earthquake was located 0.84 degrees south latitude, 99.65 degrees east longitude at a depth of 71 km below the sea surface. The quake’s epicenter was located about 78 km north-west of Padang city, 99 km south-west of Bukittinggi, or 106 km north-east of Mentawai Islands.

The quake’s tremors were even also felt in the provinces of Riau, North Sumatra and Bengkulu. Shortly after the quake, an aftershock measuring 6.2 on the Richter scale rattled the province at 5.38 p.m. on Wednesday.

The aftershock was centered 22 km southwest of Pariaman in West Sumatra province at a depth of 110 km, according to the Meteorology, Climatology and Geophysics Agency (BMKG). The quake also damaged telecommunication networks in the region.

"Cellular communication services by voice or short messages have been disrupted," chief of state telecommunications operator Indosat’s public relations Adita Irawati told ANTARA. She said the quake had damaged the Indosat office building in Padang, the capital of West Sumatra, but none of its employees had been killed.

She stated that the company kept monitoring service conditions in the field because disruptions of networks as well as traffic may increase. After a 7.6-magnitude quake hit West Sumatra on Thursday, Jambi was also shaken by a 5.5-magnitude aftershock at 9.20 am local time.

The temblor’s epicenter was located 2.28 degrees southern latitude, and 101.54 degrees eastern longitude, around 28 km southeast of Sungai Penuh (Jambi Province), at a depth of 10 km. The previous 7.0 earthquake rocked Sungai Penuh, Jambi Province, southeastern Sumatra Island, on Thursday at 8.52 am local time.

The quake’s epicenter was located 2.44 degrees southern latitude and 101.59 degrees eastern longitude, around 46 Km southeast of Sungai Penuh (Jambi), at a depth of 10 km.

The temblor was so strong that it could also be felt by residents in places as far as Bengkulu. Reports on casualties or damage were not immediately available.

On Thursday, it was the turn of the Talaud Islands in North Sulawesi province to be rocked by a 5.5-magnitude earthquake at 9.30 am. The epicenter of the quake was 20 kilometers deep, 76 kilometers northeast of Melonguane Talaud, North Sulawesi, Tri Hariyono, an staff of the Meteorology, Climatology and Geophysics Agency in Manado, said.

He said the temblor was an aftershock following a 5.1 strong quake 41 kilometers northwest of Melonguane and 5.8 quake 87 kilometers northeast of Melonguane on Wednesday. He said the quake did not cause damage and people in Talaud, Sangihe, Sitaro or Manado had not felt the tremor.

He said quakes often struck in the region but their magnitude was not as high as had already been released during the big quake last February. "When the big quake occurred it was believed that a great deal of energy had been released and therefore the present quakes were not so strong," he said.

According to him, smaller quakes were also recorded in the region on September 29 and September 27. He appealed to people in Sangihe, Sitaro and Talaud islands to remain calm as no real danger was imminent.

Indonesia sits on the Pacific "Ring of Fire" where the meeting of continental plates causes high volcanic and seismic activity.

Sumber : Antara