Figure6-6 Extension and Compression in the Chubu region.

The directions of the two straight lines that cross each other in the figure are those of the maximum extension (or minimum compression; red) and the maximum compression (or minimum extension; blue). Also, the lengths of the straight lines are in proportion to the amount of the extension or compression.

[Compiled from data from Geographical Survey Institute and "Active Faults in Japan (Revised Edition)"]

A:The past approximately 100 years.


In the west side of the Itoigawa-Shizuoka tectonic line, overall compression is seen from a northwest-southeast direction to an east-west direction. The high values near the Fukui Plain (Hukui Heiya) are a result of the 1948 Fukui Earthquake.

B:The past approximately 10 years.


In the northern Izu Peninsula, earthquake swarms and submarine volcanic eruptions reflect the marked extension.