The Collapse of Genbudo Cave
On September 3, 1998, a 6.2 magnitude earthquake rocked the northern part of Iwate Prefecture, not far from Kakkonda, and a fault line formed in the vicinity. The fault near Kakkonda is thought to have opened because of the tremors and crustal deformation resulting from the earthquake. Exactly one year later, on September 3, 1999, the bedrock supporting the large Genbudo Cave in Kakkonda collapsed. The sediment and debris from the collapse blocked a nearby river, temporarily changing the course of the waterway.
Photo Title: The Formation of Columnar Jointing
Caption: When lava cools, it shrinks in the direction of the arrows in the image.