DIAPASON S1 Interferogram Japan Earthquakes April 2016

Sentinel-1 interferogram generated in the cloud on the Geohazards Exploitation Platform (GEP), the initiative developed by the European Space Agency (ESA).

The interferogram was generated on the platform and shows the ground displacement caused by the earthquakes that struck Japan in mid-April 2016. Two major earthquakes caused significant damage in and around the city of Kumamoto, on the island of Kyushu in southwest Japan. The first quake occurred on Thursday 14 April with a magnitude of 6.2 and was followed by several aftershocks until the bigger 7.0 magnitude quake on Friday 15 April which led to the earlier, smaller event to be reclassified as a foreshock. Both events are included in the period covered by the interferogram made with two Sentinel-1 images: one on 08 April (prior to the events), the other on 20 April 2016.

The epicentres of the earthquakes were relatively close to the surface, at a depth of about 10 kilometres. According to the USGS the shallow depth and faulting mechanism of these earthquakes indicate that they occurred on a crustal fault within the upper Eurasia plate. In contrast to this recent sequence of shallow earthquakes, most seismicity in the Kyushu region is related to the subduction of the Philippine Sea plate at depth.

The two earthquakes killed more than 40 people and caused several structures to collapse. The resulting landslides have destroyed roads and communities.