Insights from an Earthquake Scientist: Current Understanding and Future Possibilities of the Taiwan Earthquake

A major earthquake with a magnitude of 7.4 hit the central east coast of Taiwan today, approximately 20 kilometers south of Hualien City. Witnesses near the epicenter reported severe ground shaking, making it difficult to stand or drive. The earthquake was felt across Taiwan and in neighboring China. The quake has resulted in at least four deaths and dozens of injuries. Hualien City, with a population of around 100,000, experienced building damage. Landslides also occurred along the mountainous central east coast. A tsunami warning was issued for Taiwan, Japan, and the Philippines, with a 30 cm tsunami reported along the south coast of Japan. The earthquake was detected by Taiwan’s early warning system, providing crucial seconds of warning for those away from the epicenter. Initial estimates suggest the earthquake began between 10 and 40 kilometers beneath the surface, with a shallow earthquake producing stronger ground shaking and more potential for building damage. The earthquake occurred on a reverse fault, which can generate a tsunami. There have been 13 aftershocks greater than magnitude 5.0 within three hours of the initial quake. The Hualien region has experienced earthquakes before, with a magnitude 6.4 earthquake in February 2018 resulting in 17 deaths. The region experiences earthquakes larger than magnitude 7 about once every 30 years. The largest recent recorded earthquake in Taiwan was the magnitude 7.6 Chi-Chi quake in 1999, which caused over 2,400 deaths. Aftershocks from today’s earthquake are expected to continue for days and weeks. It is important to be cautious about information shared on social media and to follow updates from Taiwan’s Central Weather Administration for accurate information on aftershocks and tsunami warnings.