"Your Guide to Earthquake Safety"

Types of earthquake

＜Figure 1＞

The earthquake is classified into two types. One is the “oceanic trench type” and the other is the “inland type”.

The oceanic trench type is the earthquake, which occurs at the plate boundary between the oceanic and continental plates.

As shown in Figure 1, the continental plate is pulled by the oceanic plate which gets into the continental plate.

＜Figure 2＞

When the distortion reaches the destruction limit, the continental plate jumps in order to cancel the distortion and the earthquake occurs.

The Great Kanto earthquake in 1923 and the Sumatra earthquake in 2004 are belonging to type. The inland type is the earthquake occurring in the plate, which usually has shallow focal depth.

＜Figure 2＞

This type is also called as near-field earthquake.

This type of earthquake causes considerable damage to the people because it sometimes occurs near the town, even if the earthquake energy is small.

The active fault is one of the causes of the inland earthquake, so that we recommend you to understand the active fault in the area where you are living.

The fault types are shown in Figure 2.
The Great Hanshin earthquake in 1995 and the Chuetsu earthquake in 2004 are belonging to type.