[April 12, 2024] M 7.1 Earthquake Hits Southern Japan
On April 8, 2024 an earthquake struck the east coast of southern Japan, near Miyazaki.
The event created strong shaking, caused minor injuries, triggered a tsunami advisory and concerns about it raising the level of risk from
larger earthquakes in the Nankai trough.
While the event struck offshore with an epicenter east of the Pacific Coast, it was large enough to move stations in
Japan's GNSS Earth Observation Network System (GEONET) significantly.
The Nevada Geodetic Laboratory processed data with the Jet Propulsion Laboratory's GipsyX software and rapid orbit products
to generate 5-minute position time series at all stations in their network.
We computed the differences in positions with 7 days of data before and ~16 hours of data after the earthquake.
The coseismic displacement pattern (red vectors in figure below) shows coherent movement towards the coast and epicenter, consistent with the event's thrust mechanism.
The USGS page for this event describes the parameters of the event, including the moment tensor that is shown in the figure.
The largest displacement was at station G088, which moved over 13 cm to the southeast, towards the epicenter.
A preliminary coseismic displacement table is available HERE.
A slip model developed by the USGS using these data can be seen HERE.
Coseismic displacement estimates will become more accurate as more post-event data are collected.
The figure below the map shows the 5 minute sample rate time series for station G088. The event time on 8 Aug 2024 is shown with the green dashed line.
