Earthquake in Hualien County of Taiwan  

Hualien County area of Taiwan has been stuck with a powerful earthquake of magnitude (ML) 7.2 on 03 April 2024 at 07:58:09 hours local time. The epicentre was 23.77°N, 121.67°E 25.0 km SSE of Hualien County Hall at a focal depth of 15.5 km. Many aftershocks of varying intensities have been recorded so far. It is still an evolving situation hence accurate estimate of damages to human lives and properties is unavailable.  

The last major seismic activities in the Hualien County were 2021 Hualien earthquake swarm and the 2018 Hualien earthquake sequence (earthquake sequences have foreshocks, main shock and aftershocks while earthquake swarms have no discernible main shock). 

The Hualien and Taitung counties in eastern Taiwan undergoes intense seismic activity because this region is situated along the collision boundaries of two tectonic plates. The Philippine Sea Plate moves northwest at a rate of about 8 cm/year and collides with the Eurasian Plate generating high seismic activity in the area.  

Many intense earthquake sequences have occurred in the region in the past such as 1951 Hualien-Taitung earthquake sequence, the 1986 Hualien earthquake sequence, the 2002 Hualien earthquake sequence, the 2018 Hualien earthquake sequence, the 2021 Hualien earthquake swarm and 2022 Chihshang earthquake sequence in the northern part of Taitung. The 1951 and 2018 earthquakes caused severe damage to life and properties in the region. 

In the last major seismic event of 2022 Chihshang earthquake sequence in the northern Taitung County in eastern Taiwan, most foreshocks occurred around the mainshock, while the aftershocks happened outwards from the foreshock area. Also, the foreshock and the mainshock released most of the energy during the sequence. 

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References:  

1. Central weather administration of Taiwan. Earthquake Report No.019. Available at https://www.cwa.gov.tw/V8/E/E/EQ/EQ113019-0403-075809.html 

2. Chen Kou-Cheng et al 2024. Some characteristics of foreshocks and aftershocks of the 2022 M_L6.8 Chihshang, Taiwan, earthquake sequence. Front. Earth Sci., 04 March 2024. Sec. Solid Earth Geophysics Volume 12 – 2024. DOI: https://doi.org/10.3389/feart.2024.1327943 

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