Samantha Boh The Straits Times AsiaOne 10 Jun 15;
The chances of a serious earthquake in Singapore remain extremely low, given that its nearest fault line is 300km away in eastern Sumatra, said veteran geologist Kerry Sieh.
He said last Friday's 6.0-magnitudequake in Sabah, though rare, was the result of a shifting 10km fault line about 10km beneath the surface, south of Mount Kinabalu.
"Unlike Sumatra, Nepal, Taiwan and Japan, which straddle fast-moving tectonic plate boundaries, Sabah is not a place well known for destructive quakes," said the head of the Earth Observatory of Singapore at Nanyang Technological University. There have been three quakes of such intensity there in the last century.
Professor Sieh and his team are now poring through seismic recordings from around the world, measurements of ground deformation from orbiting satellites, and analyses of Sabah's mountainous topography to understand what happened and why. They suspect that the fault in question is part of a system of faults that runs nearly 200km across Sabah.
Prof Sieh noted that there has been no record of an earthquake in Singapore to date, although weak tremors are felt occasionally from distant quakes. While there is no such thing as absolute certainty in earthquake prediction, he stressed that unlike Sabah, there is no indication the plate Singapore is on is "mildly cracking".
His team plans to try and pin down what exactly happened in Sabah, and put appropriate safety measures in place.
Earth now in active seismic cycle: Expert
The Earth goes through cycles of these seismic activities, with periods of greater frequency and magnitude, and it is now in an active cycle, says a geologist.
Janice Lim Channel NewsAsia 10 Jun 15;
SINGAPORE: Nature's wrath struck in 2004, when a tsunami hit the coasts of several countries around the Indian Ocean. This marked the beginning of what geologists call an "active cycle", where the Earth experiences greater seismic activity.
Said Professor Kerry Sieh, director at the Earth Observatory of Singapore: "The Earth goes through cycles of seismic energy release, and less release and more release.
"We have definitely been in the active cycle in the last 11 years since 2004. All the magnitude-8.4 earthquakes and bigger, up to 9.2, they all happened in the last 11 years. Several of those have been in Asia."
The previous active cycle was in the 1950s to mid-1960s, which saw several earthquakes with a magnitude of a high 8 and above 9. But for the next 40 years, there were no records of a quake with a magnitude above 8.3, until 2004.
Since then, a string of devastating earthquakes has caused much destruction, like in Sumatra in 2005 and Fukushima, Japan, in 2011.
"We don't know whether we are at the end of the cycle or not," said Professor Sieh. "My hunch is we will continue to see a larger number of large earthquakes. But that's only a hunch because we don't really have a way of telling whether we are at the end of the cycle or not."
In response to the recent Sabah quake, Professor Sieh supported the call by Malaysia's Youth and Sports Minister Khairy Jamaluddin to relook safety protocols for climbers on Mount Kinabalu and also offered his team's expertise.
- CNA/hs
