Historic Seismicity Animations: Izu-Bonin, Mariana: 1940 – 2015

Following up on the seismicity in the western Pacific, I put together a couple animations. My post about the deep mainshock (magnitude M = 7.8 ) is here. My second post has some aftershocks plotted (and some foreshocks), as well as a little more about this series of earthquakes.

Here are a couple animations that show the seismicity in the western Pacific for the time span of 1940 through the end of May, 2015. These earthquakes were downloaded from the USGS NEIC using the html based query, using this search. The diameter relates to earthquake magnitude and the color represents the depth. These earthquakes have magnitudes greater than or equal to M = 7 and span the period from 1940 through May 2015.

I also have placed an overlay of the oceanic crustal age that I downloaded from here: Les SVT dans l’académie de Versailles. Color represents age. The ichrons have 5 Ma spacing.

Here is a screenshot showing all earthquakes included in the following animations.

1940 – 2015 with no moving window. Link to the file here.

1940 – 2015 with 5 year moving window. Link to the file here.

Also, here is another cross section in the same region as the M 7.8 earthquake. This is from the USGS poster about the seismicity in this region (Rhea. This legend for this cross section is here.

Here is the cross section. Note again, how this M 7.8 earthquake does not fit the existing slab model.


  • Rhea, S., Tarr, A.C., Hayes, G., Villaseñor, A., and Benz, H.M., 2010, Seismicity of the Earth 1900-2007, Japan and vicinity: U.S. Geological Survey Open-File Report 2010-1083-D, 1 map sheet, scale 1:5,000,000.
Category(s): asia, Chemeketa Community College, education, geology, HSU, plate tectonics, subduction, Transform

Leave a Reply

Your email address will not be published. Required fields are marked *