Taiwan: The Highest Seismic Activity in 2024
On April 3, 2024, a strong earthquake with magnitude M 7.4 struck the eastern coast of Taiwan1. At the same time, Taiwan recorded the highest seismic activity in 2024 since the beginning of precise seismic monitoring2. The largest aftershock, with magnitude M 6.5, occurred 13 minutes after the main shock, indicating significant seismic activity in the region3. The earthquake was so energetically intense that it also generated unusual waves in the ionosphere4.
Fig. 1: Number of earthquakes with M ≥ 4.5 around Taiwan, data: USGS https://earthquake.usgs.gov/earthquakes/search/
Fig. 2: Analyzed zone around Taiwan, source: Google Earth, own modification
As shown in Figures 1–2, based on data from the USGS catalog, seismic activity in Taiwan increased significantly in 2024. This increase is closely related to the strong earthquake of magnitude M 7.4, which triggered an extraordinarily extensive aftershock sequence. The total number of earthquakes with magnitude M ≥ 4.5 in 2024 reached the highest values in the entire observed period since 1980 and significantly exceeded even the year 1999, when the island was struck by an even stronger M 7.7 earthquake (Chi-Chi) in western central Taiwan5. While after the 1999 earthquake the annual number of M ≥ 4.5 events was around 130, in 2024 this number exceeded 225 events. The graph therefore clearly illustrates that although the main shock in 2024 was slightly weaker than in 1999, the subsequent seismic response was substantially more intense, indicating exceptionally elevated seismic activity in the recent period.
Increased seismic activity can also be observed in the graph in Figure 1 in 1986, when Taiwan was struck by an equally strong earthquake on the eastern coast of the island with a magnitude of approximately M 7.46. This event was reflected in a significant increase in the number of M ≥ 4.5 events, which, however, remains lower compared with 2024. The graph shows that in 1986 the annual number of earthquakes with magnitude M 4.5 and higher was about 200 events, while in 2024 this number significantly exceeded the threshold of 225. Both earthquakes occurred in the same location near the city of Hualien, while the 2024 earthquake had a greater hypocentral depth (40 km) compared with 34 km for the 1986 earthquake.
The graph of the number of earthquakes with magnitude M ≥ 4.5 in the Taiwan region according to the USGS database in Figure 1 shows a clear and long-term increasing trend in seismic activity since the 1980s. While in the 1980s annual counts were mostly on the order of several dozen events, from the turn of the 1990s and after 2000 a stable increase in the average annual value is visible, gradually moving toward higher tens to more than one hundred earthquakes per year. In the last decade, pronounced maxima have also appeared, indicating a consistent increase in the number of these earthquakes.
References:
M 7.4 - 15 km S of Hualien City, Taiwan. Available at: https://earthquake.usgs.gov/earthquakes/eventpage/us7000m9g4/executive (Accessed: March 16, 2026).
Kothari, R. (2024) “Taiwan logs record seismic activity with 42 quakes surpassing M5.5 in 2024” . Available at: https://watchers.news/2024/12/07/taiwan-logs-record-seismic-activty-with-42-quakes-surpassing-magnitude-5-5/ (Accessed: March 16, 2026).
Qiu, J. et al. (2025) “Coseismic deformation and seismogenic structure of the 2024 Hualien Earthquake measured by InSAR and GNSS,” Earthquake Research Advances, 5(1), p. 100328. Available at: https://doi.org/10.1016/j.eqrea.2024.100328.
Mao, Z. et al. (2025) “Seismo-Traveling Ionospheric Disturbances from the 2024 Hualien Earthquake: Altitude-Dependent Propagation Insights,” Remote Sensing, 17(7). Available at: https://doi.org/10.3390/rs17071241.
M 7.7 - 21 km S of Puli, Taiwan. Available at: https://earthquake.usgs.gov/earthquakes/eventpage/usp0009eq0/executive (Accessed: March 16, 2026).
M 7.4 - 8 km SSW of Hualien City, Taiwan. Available at:https://earthquake.usgs.gov/earthquakes/eventpage/usp0003009/executive (Accessed: March 16, 2026).