18 April 2016

Landslides from the Kumamoto earthquake in Japan

Posted by Dave Petley

Landslides from the Kumamoto earthquake in Japan

The Kumamoto earthquake, the second of the two significant earthquakes that Japan over the last three days, and the associated aftershocks, appears to have generated significant numbers of landslides.  Experience tells us that the area most affected by earthquake-induced landslides will be the terrain with significant slopes that has a high concentration of aftershocks.  The largest landslide seems to be a very substantial slope failure close to Mimami-Aso that destroyed an important bridge.  Asia One has a quite beautiful image of this landslide:

Kumamoto earthquake

A landslide triggered by the Kumamoto earthquake, via Asia One

.

This appears to be a large rockslide in weathered rock.  Note that the crown extends almost to the ridge, which is common in earthquake induced landslides.  This landslide must have deposited a large volume of material in the gorge.  Note also that the other slopes along the gorge have failed too, as this AP image shows.  There is a reasonably large landslide towards the left side of the image that has come close to destroying another bridge:

Kumamoto earthquake

A landslide triggered bu the Kumamoto earthquake, via AP

.

However, this is by no means the only landslide.   AFP have an image of a landslide that appears to have caused serious damage to the Kurowa Dai-ichi power station:

Kumamoto earthquake

Damage to the Kurokawa Dai-ichi Power Station caused by the Kumamoto earthquake, via AFP

.

There are also some images of a quite peculiar and deeply intriguing flowslide.  AP have this image of the debris in the fields:

Kumamoto earthquake

A flowslide triggered by the Kumamoto earthquake, via AP

.

Whilst the BBC has some nice video footage of it.  There seems to be quite a large amount of landslide damage to roads.  This appears to be a major cutslope failure:

Kumamoto Earthquake

A major cutslope failure on the Oita Expressway, triggered by the Kumamoto Earthquake, via AP

.

Other road damage seems to have been caused by the failure of fill slopes:

Kumomata earthquake

Road damage caused by the Kumomata earthquake via Asia One

.

 Kumomata Earthquake

Highway damage caused by the Kumomata Earthquake, via Asia One

.

If you have links to further images please post them in the comments.