56 aftershocks follow quake in eastern Taiwan

台灣東部在地震後發生56次餘震

Quake linked to Central Mountain Range fault activity: seismologist


TAIPEI (Taiwan News) — Over 50 aftershocks have occurred in Taitung and Hualien following a major 6.4 earthquake that rocked Taitung with an intensity level of 6 on Saturday evening (Sept. 17).

At the time of publication, the Central Weather Bureau’s (CWB) Seismological Center had detected 56 aftershocks ranging from 3.2-5.5 in magnitude. Over 50 occurred in Taitung.

The aftershocks’ intensity levels, which gauge the degree to which a quake is felt at a specific location, ranged from levels 1-5.

The head of the Seismological Center, Chen Kuo-chang (陳國昌), said during an interview that the Saturday quake was the second largest of the year in terms of magnitude and the strongest in terms of intensity level. The earthquake that struck the east coast on March 23 had a magnitude of 6.7 and an intensity level of 6.

Chen called the quake “strange,” as there is no destructive or obvious fracture zone at the epicenter in Guanshan, Taitung. Per data since 1973, the surrounding area within a 10- to 15- kilometer radius has not seen such a quake exceeding 6 in magnitude; only seven quakes with magnitudes over 5 have been recorded, with the largest reaching 5.5 in 1998.

Chen said that despite its unusual location, the earthquake may be related to fault activity in the Central Mountain Range, which has always been active.

In the next couple of days, the area may see more aftershocks, according to Chen. In the next five days, the magnitude of aftershocks may reach intensity levels of 4 or even 5 in the next two days.

The Seismological Center also reported that the Saturday evening quake was this year’s seventh quake to reach a magnitude over 6. The number of such large quakes this year is unusually high, as in the past, the number averaged two to three a year.