How safe is Singapore from earthquakes?

Tuesday last week, while I was enjoying my Penang laksa at Penang Place, the earth moved.

Tremors were felt in some parts of Singapore as reported by CNA. Ask Ogster and he'll say he didn't feel it. How about you Nalen?

Here's the bulletin issued by the NEA's Meteorological Services Division (6 Mar 2007 at 2:15 pm):

An earthquake was detected at 1:49pm, 6 Mar 2007 in CENTRAL SUMATRA, approximately 420km from Singapore. The magnitude of the earthquake is 6.6 on the Richter scale. The epicentre is located at latitude 0.3 South and longitude 100.4 East.

In Sumatra, 70 people were reported to have perished. Dozens of buildings have been destroyed and hundreds others damaged.

Is Singapore free from earthquakes?

In known history, Singapore has not experienced an earthquake (see tremor).

Singapore is located in an area sandwiched by the Sunda trench in the west and south, and the Philippine plate and trench in the east. Thus Singapore is located in a seismically stable zone, free from earthquakes. Most of the shallow and bigger earthquakes are in western Sumatra and Java because of the deep subduction zones to the west-east and south-north of the Sunda trench. Earthquakes that occur near Singapore are usually deep earthquakes and weak.

However this does not exclude the island's inhabitants from being affected by weak tremors once or twice a year due to a strong earthquake located in western Sumatra. The tremors are weak and are felt by a few people living on high floors over certain specific areas of the Singapore.

Here, where most people work and live in high-rise buildings, last Tuesday's tremors was enough to cause some buildings to be evacuated and occupants had to wait outside in the open.

In the worst case scenario, an earthquake measuring 9.5 at 600 km away could damage some old-high-rise buildings. But chances of such an earthquake are rare in the next 200 years, experts say.

"Life is like a box of chocolates. You never know what you're gonna get." - Forrest Gump