Earthquake Information:

20. What do the effects of the crustal deformation look like in Taiwan?

The major earthquake activities in Taiwan over the past years all appear as different forms of crustal deformation, such as ruptures of the Earth surface, landslides, and faults, etc. For example, on March 17, 1906, the very strong earthquake in Chiayi caused the formation of the Meizikeng Fault, which was 13 kilometers long, with the maximum horizontal displacement of 240 centimeters and maximum vertical displacement of 180 centimeters. Clay blasts and surface ruptures were remarkable phenomena found in many places.

On April 21, 1935, Hsinchu and Taichung also had a very strong earthquake. The Tunzijiao Fault and the Shitan Fault were formed due to these. The Tunzijiao Fault was more than 10 kilometers long and the Shitan Fault was more than 20 kilometers long. The maximum horizontal displacement was 150 centimeters and maximum vertical displacement was 3 meters. Land sinking, landslides, surface ruptures and clay blasts were found in many places.

On December 17, 1941, the very strong earthquake in Chiayi did not cause any faults. However, it triggered many huge landslides instead. The mountain mass in Caoling moved 2,500 meters, and the falling rocks stacked up in the river valley. This earthquake induced a dammed lake called Qingshui Lake, which is rarely found in the world.

On December 5, 1946, Tainan strong earthquake caused the Xinhua Fault, which were 12 kilometers long with a maximum horizontal displacement of 220 centimeters and maximum vertical displacement of 200 centimeters. Clay blasts and surface ruptures were found in many places.

On September 21, 1999, the Jiji (Chi-Chi) earthquake caused around 100 kilometers of surface rupture from the Chelungpu Fault, with a maximum horizontal displacement of 7 meters and maximum vertical displacement of 4 meters. Sand and clay blasts were found in many places.

These are examples of obvious crustal deformation caused by earthquake.

19. What is the classification of earthquake-resistant standards for buildings in Taiwan?  21. What is the cause of a tsunami?