April 2, 2024 Earthquake: Hua-Lien, Taiwan

Ref #13456:

At least 17 people killed by rockfalls in Hualien, including 10 hikers in Tailuge Guojia Gongyuan, 5 on sections of the Provincial Highway and 2 at a mine near Xiulin. At least 1,145 people injured; 111 buildings destroyed; 1,939 houses, 870 buildings and 75 roads damaged, including 1,400 houses in Hualien; widespread gas, power and water outages occurred; railway service partially suspended across Taiwan. A total of 779 landslides occurred and a large portion of Guishan Dao collapsed into the ocean. A tsunami generated with maximum wave heights of 100 cm at Hualien, 82 cm at Toucheng and 45 cm at Chenggong, Taiwan; 30 cm on Miyako-jima and Yonaguni Jima and 20 cm on Ishigaki Jima, Ryukyu Islands.

Tectonic Summary

The April 2, 2024, M 7.4 earthquake on the eastern coast of Taiwan occurred as the result of reverse faulting near the boundary between the Eurasia and Philippine Sea plates. The earthquake was followed by a M 6.5 aftershock 13 minutes later. The M 7.4 earthquake occurred in a zone of tectonic transition from eastward-oriented subduction of the Eurasia plate to westward-oriented subduction of the Philippine Sea plate. Focal mechanism solutions for the earthquake indicate that rupture occurred on a northeast-southwest-striking, moderately dipping, reverse fault. Given the location, depth, and mechanism of the earthquake, it is likely associated with faulting within the Eurasia plate, above the subduction zone interface. At the location of the earthquake, the Philippine Sea plate is moving northwest with respect to the Eurasian plate at a velocity of about 78 mm/yr.

While commonly plotted as points on maps, earthquakes of this size are more appropriately described as slip over a larger fault area. Reverse faulting events of the size of the April 2, 2024, earthquake are typically about 60 by 35 km in size (length x width).

This tectonically complex region has historically produced many other large earthquakes of M 7+. Over the preceding 50 years, six other M7+ earthquakes have occurred within 250 km of the April 2, 2024, earthquake. The largest of these was an M 7.7 earthquake in September 1999 (the Chi-Chi earthquake) that resulted in at least 2,297 fatalities, caused damage estimated at $14 billion, and occurred 59 km east of the April 2, 2024, event. In 1920, a magnitude 8.2 earthquake, potentially associated with the subduction zone interface between the Philippine Sea and Eurasia plates, occurred immediately east of the April 2 earthquake.

Ref #13758, #13761,#13764, #13765, #13773:

As of Wednesday, the earthquake has caused a total of 80.96 million new Taiwan dollars (about 2.53 million U.S. dollars) in damage to agricultural products as well as private and public facilities, with Hualien County suffering severe losses

[…] numerous roads, bridges, and buildings have been destroyed; 111 buildings are structurally compromised or collapsed, affecting 1,939 households, with 297 other buildings requiring minor repairs

The earthquake has claimed 18 lives and a Singaporean couple remains missing

Ref #13916:

the Hualien District Court issued death certificates for the [missing] couple following

Ref #1250:

20 deaths, 1145 injured, 2.53 million USD in damages [possibly a typographical error and should be 2.53 billion]

Ref #13923:

Following a January earthquake in Japan that produced losses in the billions, the earth also shook near Hualien, Taiwan in April. The magnitude 7.3 earthquake was the worst disaster in the region since 1999; total losses were US$ 4.6bn, only US$ 0.8bn of which were insured.

Ref #13924:

2,500 million in economic losses

Ref #14358:

18 deaths and 1155 injuries occurred in the aftermath of the earthquake, and 17 people died because of coseismic landslides (mainly rockfalls).