Seismologist explains how areas of Taiwan are shifting due to plate tectonics

Seismologist explains how areas of Taiwan are shifting due to plate tectonics

2022-11-02

Earlier this week the Central Weather Bureau shared two maps online showing how different areas of Taiwan are moving on the earth’s surface due to plate tectonics. The maps show how some areas of Taiwan have shifted position at a rate of up to 8 centimeters per year between 2009 and 2018. The maps have attracted a lot of attention online, with commenters wondering whether that could mean that Taiwan is slowly drifting away from China into the Pacific.

On Monday evening, another earthquake struck at Taitung’s Donghe Township. Fortunately, no people were hurt. Tremors like these often shake Taiwan, because of the movement of tectonic plates. These ground movements also gradually shift Taiwan’s location in the world.

The Central Weather Bureau recently released two maps showing the absolute speed and relative speed at which different areas of Taiwan moved due to tectonic action between 2009 and 2018. The blue arrows represent the direction of the shift, and their length represents the distance of the movement. The maps left some internet users wondering whether that meant that Taiwan was gradually moving away from China. A seismologist says that’s not the case.

Chao Hsiao-ling
Taiwan Earthquake Research Center
the Eurasian plate covers both west Taiwan and China. They are on the same continental plate, meaning they move in the same direction. Taiwan and China are moving together.

Taiwan is located at the convergent boundary between the Eurasian Plate and the Philippine Sea Plate. Thanks to a network of sensors, researchers found Taipei is moving by 0.5 centimeters every year. Over at the rift valley running through Hualien and Taitung, the speed is 6 centimeters per year. According to the findings, the fastest moving area is Orchid Island, which is shifting toward Taiwan proper at a speed of 8 centimeters per year. The network of 450 sensors provides valuable information on seismic faults and volcanic activity as well as data on subsidence and sliding underground. They hope the data can help scientists find signs that a big earthquake is going to strike. They add that tectonic movements will eventually cause the island of Taiwan to be thinner and more elongated in the future.

Chao Hsiao-ling
Taiwan Earthquake Research Center
This plate is pressing from here, and this other one from over there. So Taiwan will gradually become thinner. Over the short term, it won’t be a difference big enough for anyone to notice a big change.

Seismologists remind that, on a tectonic scale, 10 years is just the blink of an eye. Seeing Taiwan change shape from a sweet potato into a banana will be a matter of several million years, they add.