Two magnitude 5+ aftershocks linked to April 3 earthquake: CWA

Taipei, May 30 (CNA) Two earthquakes with magnitudes over 5 which hit off the east coast of Hualien in the morning were aftershocks linked to the April 3 magnitude 7.2 quake that struck the eastern country, the Central Weather Administration (CWA) said on Thursday.

According to CWA information, a magnitude 5.3 earthquake occurred at 9:11 a.m. on Thursday, 22.8 kilometers northeast of Hualien County Government, off the coast of Hualien County.

The earthquake had a depth of 17.9 kilometers and a maximum intensity of level 4 in Hualien County, Nantou County and Taichung.

In addition, at 7:54 a.m., a magnitude 5.1 earthquake struck 12.7 kilometers east of Hualien County Government, also off the eastern coast of Taiwan, the CWA said.

That earthquake hit at a depth of 17.1 kilometers and had a maximum intensity of level 4 in Hualien City, it added.

Liao Che-wei (廖哲緯), head of the earthquake monitoring section at the CWA's Seismological Center, said at a press conference on Thursday that both earthquakes were determined to be aftershocks linked to the April 3 Hualien earthquake, but occurred in a more northern location.

He noted that while the magnitude and frequency of aftershocks have significantly decreased, isolated earthquakes with magnitudes above 5 may still occur.

Liao said that the CWA issued a national alert for the magnitude 5.1 earthquake that hit Hualien and a targeted alert for the magnitude 5.3 earthquake in Yilan and Hualien.

Liao explained that the Hualien earthquake rupture zone from April 3 spans approximately 70 kilometers from north to south.

It is assessed that significant aftershocks may occur within three to six months after the mainshock as part of the "stress adjustment process," he said.

The stress adjustment process is the redistribution of stress within the Earth's crust that occurs due to tectonic activity.

He noted that, so far, the frequency of aftershocks has significantly decreased. The aftershocks have always hit north and south of the mainshock, Liao added.

He reminded the public to be aware of possible landslides and falling rocks in mountainous areas following earthquakes, especially due to recent frequent rainfall.

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