What Caused the 2024 Taiwan Earthquake?

The 2024 earthquake in Taiwan was caused by the movement of tectonic plates.

The recent earthquake that struck Taiwan on April 3rd, 2024, was a powerful reminder of the island's vulnerability to seismic activity. This major earthquake, registering between 7.2 and 7.4 on the Moment Magnitude Scale (Mw), resulted in significant ground shaking and damage, particularly near the epicenter close to Hualien City. But what exactly caused this powerful event?

The culprit lies deep beneath Taiwan's surface, in the movement of gigantic tectonic plates. The island sits on a complex zone where the Philippine Sea Plate dives beneath the Eurasian Plate in a process called subduction. This ongoing subduction is responsible for creating the mountainous island of Taiwan itself.

What Caused the 2024 Taiwan Earthquake?

However, subduction isn't a smooth process. As these massive plates grind against each other, immense pressure builds up along fault lines - cracks within the Earth's crust. The 2024 earthquake is attributed to a specific type of fault movement called reverse faulting. Imagine two slabs of rock pushing against each other. In reverse faulting, instead of slipping horizontally, the overriding plate (the Eurasian Plate in this case) is thrust upwards against the subducting Philippine Sea Plate. This sudden shift in position triggers the release of the built-up pressure as seismic waves, causing the earthquake.

Taiwan's location intensifies this phenomenon. The island occupies a precarious position between two constantly converging plates, pushing against each other at a rate of about 75 millimeters per year. As the denser Philippine Sea Plate subducts beneath the Eurasian Plate, it creates the Luzon Arc, the chain of islands that includes Taiwan. This continuous grinding builds up immense stress along fault lines, setting the stage for future earthquakes.

The depth of the earthquake also played a role in its impact. The epicenter was located at a relatively shallow depth of 34.8 kilometers. Shallower earthquakes tend to cause more intense shaking on the surface compared to deeper ones. This explains the significant ground shaking felt throughout Taiwan during the April 3rd event.

While the 2024 earthquake's magnitude surpassed the devastating 1999 Jiji earthquake (Mw 7.7), its deeper depth (35 km compared to 17 km) might have lessened the destructive surface shaking. Nevertheless, the recent event serves as a stark reminder of the ever-present threat of earthquakes in Taiwan and the importance of preparedness for future seismic activity.