Archive for Tremors
(An excerpt from Bernama dated 15-October’2009)
Link: http://www.bernama.com/bernama/v5/newsindex.php?id=447156 By: By Bashariah Zainuddin
Since the end of 2007, 40 tremors were recorded in Malaysia but the significant fact was that 37 incidences of these seismic activity occurred along the fault line in Bentong, Pahang.
The three others recorded were in Manjung (Perak) and Jerantut (Pahang).
Meterological Department Director Dr Rosaidi Che Abas said from November 2007 until May last year, Bentong recorded 29 cases of tremors, also known as ‘temblors’.
The latest tremors were recorded last Oct 8 where there were eight, that measured between 4.45am and 12.05 noon recorded between 1.1 and 2.8 in magnitude on the Richter scale.
All of these tremors were detected at Bukit Tinggi and Janda Baik, along the fault line of 15 km wide and 70 km long. However only in one incident that the Meteorological Department detected a strong tremor of 3.5 in magnitude on the Richter scale.
“What we can say is that even though Bukit Tinggi and Janda Baik are located on the fault line, any earthquake will not possibly surpass 5.0 in magnitude on the Richter scale which means if such an earthquake occurs, it will not cause damage to a structurally-strong building.
“We are also stressing that the tremors occurred along that fault line and not at the Titiwangsa Range which is the country’s backbone,” he told Bernama in an interview here.
CONCERNS AMONG RESIDENTS
The concerned residents of Bukit Tinggi and Janda Baik had recently called on the government to make a detailed study on the soil structure along the fault line there.
Their concerns picked a new high following the massive earthquake that hit West Sumatra last Sept 30 as the shocks and tremors were also felt at several locations in Peninsular Malaysia.
The residents claimed that despite no collapse of buildings occurred, there were damages to assets as well as cracks in the walls and floors.
According to the residents, Janda Baik and Bukit Tinggi were hit by the first tremors in November 2007 following a series of earthquakes that occurred in Indonesia and Philippines.
Dr Rosaidi said the Meterological Department will work closely with the Minerals and Geoscience Department as well as other agencies to conduct an immediate study on the earth’s surface and structure at both locations.
“We will also talk to the affected residents to know what they meant by earth movement and what they felt when this seismic activity happened.
“We also want to know the strength of the tremors said to have caused cracks in the walls and floors (of buildings),” said Dr Rosaidi.
Meterological Department Director Dr Rosaidi said so far the earthquakes that occurred were between one and 10 miles beneath the earth’s surface.
“Only on two occassions that earthquakes with the magnitude of between 2.8 and 3.5 on the Richter scale and both instances occurred 10 miles under the earth’s surface,” he said.
There are 13 seismology stations operating in Malaysia, capable of detecting quakes and tremors that occur in the country. Seven are in Peninsular Malaysia with the rest in Sabah and Sarawak. The latest seismology station to operate is in Jerantut, Pahang.
“Our officers are on duty round-the-clock. They will alert the authorities and each of their entry record is exactly the time when the earthquake happened,” he said.
Dr Rosaidi said there were four seismological fault lines detected in the country – Jerantut, Bentong, Kuala Lumpur and the latest, in Manjong Perak.
Meanwhile, Meteorological Department Director-General Dr Yap Kok Seng said any earthquake that measured 2.8 or less on the Richter scale was unlikely to cause damage and harm to life and limb.
“The tremors that happened in Bukit Tinggi was a restabilisation process of the earth’s structure at the fault line in Bukit Tinggi.
He said this restabilisation process followed the movement of the earth’s layers in the wake of the large-scale earthquakes that happened in the past few years.
Among the major earthquakes were that on Dec 26 in Aceh, Indonesia that caused the Tsunami in the Indian Ocean, Nias (Indonesia) on March 28, 2005. The latest was on Sept 30 this year that hit Padang in Indonesia and Bengkulu (Oct 1, 2009).
WHAT IS AN EARTHQUAKE?
The magnitude of an earthquake can be measured using the seismometer or seismograph that records it on the Richter scale of 1.0 to 10.0.
An earthquake that recorded 1.0 on the Richter is too small and can occur daily without being noticed.
According to the Information Department Deta Centre, earthquakes that recorded between 7.0 and 10.0 on the Richter scale were the major seismologic incidents that happened between 10 and 20 years.
The on-line centre provides information on the “dos’ and ‘don’ts” if an earthquake occurs.
It also lists out what action to be taken if an earthquake strikes for those who are in the buildings and near these structures, on the streets and in moving vehicles.
In the mean time, the Meterological Department has assured that no large-scale earthquake is expected to hit the country.