20 April 2016

Images of other landslides from the Kumamoto earthquakes

Posted by dr-dave

Images of other landslides from the Kumamoto earthquakes

In addition to the major, and well-publicised, landslides triggered by the Kumamoto earthquakes this week (which I have featured in my previous posts), there appears to be a substantial number of other major failures, many of them around the flanks of Mount Aso.  There are images of these on the websites of Kokusai Kogyo and Asia Air Survey. In this post I seek to highlight some of the more interesting ones that have been photographed by Asia Air Survey.

Asia Air Survey has a very clear image of the multiple landslides that formed the flow slide that I featured yesterday.  These appear to be shallow slides in (probably) an volcanic deposit.  Note the cracks in the slope on the left side of the image – this will be an area to watch in the forthcoming rainy season.

Kumamoto earthquakes

The area of shallow landslides responsible for the flow slide triggered by the Kumamoto earthquakes featured yesterday, via Asia Air Survey

 

Asia Air Survey also has this fascinating image of three shallow landslides:

Kumamoto earthquakes

A pair of shallow landslides triggered by the Kumamoto earthquakes, via Asia Air Survey

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There is a huge amount going on in this slope in addition to the two obvious, and one less obvious (on the counter-slope) landslides. There is extensive cracking on the ridge top, and in the upper part of the image on the main slope. Asia Air Survey also has this image of a very extensive landslide system, including a large area of highly mobile debris movement:

Kumamoto earthquakes

Multiple landslides triggered by the Kumamoto earthquakes, via Asia Air Survey

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Note the very extensive slope cracking here as well, including a series if cracks that appear to run through the building on the ridge.  I am intrigued as to whether this is a slope deformation or a tectonic crack – the position is unusual if it is the former.  The largest landslide here has flowed into two different drainage systems.

Finally, and perhaps most intriguingly, Asia Air Survey have this image of a landslide system in the vicinity of what I assume is a hot spring system:

Kumamoto earthquakes

Multiple landslides triggered by the Kumamoto earthquakes around a hot spring area, via Asia Air Survey

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There are signs here that the ground may have been altered (and probably weakened) by hydrothermal activity.  The houses in this area will need careful assessment in light of the potential for further slope activity.