CWB 'can't rule out' an even bigger quake in Taiwan soon

CWB 'can't rule out' an even bigger quake, after over 100 aftershocks have followed a deadly magnitude 6.0 earthquake in eastern Taiwan

Badly leaning Yun Tsui building.

Badly leaning Yun Tsui building. (By Central News Agency)

TAIPEI (Taiwan News) -- After eastern Taiwan's Hualien County was struck by a deadly 6.0 magnitude earthquake last night (Feb. 6) and as the area has been plagued by hundreds of smaller quakes throughout the week, the Central Weather Bureau (CWB) cannot rule out the possibility that even larger earthquake is coming soon. 

On Monday, after a magnitude 5.8 earthquake hit Hualien on Sunday, the Central Weather Bureau (CWB) counted 94 aftershocks, 40 within the first three hours after the main earthquake struck, and three of which measured over 5.0. The largest aftershock measured at 5.4.

The CWB initially reported that the aftershocks from Sunday's quake would decrease in size, however from Monday to Tuesday the opposite occurred. 

The aftershocks gradually increased in size and began to measure a magnitude of 4 then 5, eventually resulting in yesterday's magnitude 6.0 quake. By 3 p.m. today, 153 aftershocks had struck the same area, 18 of which were substantial enough to be felt. 

Both the 5.8 temblor and the 6.0 quake were preceded by magnitude 5.1 earthquake. The epicenter of the magnitude 6.0 earthquake was also in the same vicinity of both 5.1 quakes. 

Director of the CWB Seismological Center, Chen Kuo-chang (陳國昌), pointed out that generally after a powerful quake such as the one that occurred yesterday, it usually marks a turning point, after which aftershocks will occur, but will gradually trail off. However, Chen said to CNA that the flurry of aftershocks seen before and after the deadly magnitude 6.0 temblor was, "unprecedented and not a normal release of energy."

When asked by reporters if the magnitude 6.0 quake was a foreshock of an even bigger earthquake, Chen replied, "It can't be ruled out, however the probability is relatively small."

On Monday, Lee Chyi-tyi (李錫堤), a professor at NCU's Graduate Institute of Applied Geology, said that earthquakes are cyclical and in the last century in Taiwan there were two quakes with a magnitude over 8: one in 1910, which was centered off the coast of Yilan and registered 8.3 on the Richter Scale, while and the other in 1920, which also registered a 8.3, was centered off the coast of Hualien. The country has already reached the centennial of one of the 1910 temblors and will soon reach the other in two years. 

Lee told ETtoday, "For the next 10 years in Hualien, The probability of a magnitude 8 earthquake occurring is high, and I predict that there will be another earthquake (similar in size) in 2025."

Photo of a seismogram with data showing the force of Tuesday's magnitude 6.0 earthquake. (CNA image)