Category Archives: Mag 9

7 years in Japan (Tohoku Eq, 2011)

This movie shows earthquakes from Japan larger than Magnitude 3.5 (more than 10,000 events), in the years between Jan. 1, 2008 – Dec. 31, 2014. The Magnitude 9.0 Tohoku-oki earthquake was on March 11, 2011 (note the title bar in the movie says 2012, which is incorrect!). This is the same time window and distance in latitude (but not longitude) as the movie on the Caribbean and Haiti M7.0 earthquake: Haiti: The dot size is (non-linearly) proportional to magnitude and the color is proportional to depth according to these rules:
Key: .
The sound is generated by adding to the sound track tiny earthquake sounds, as described by that link.
The data comes from the ANSS catalog of the US Geological Survey, accessible from here:

Ben Holtzman, Douglas Repetto, Jason Candler, Nolan Lem. CC licence .

Magnitude 9 Tohoku Earthquake (March 11, 2011): SPECFEM with sound

This is a recent movie we put together using simulations of the Tohoku earthquake with sound from broadband seismometers (8 in a great circle mixed to stereo). We have been experimenting with ways to render the SPECFEM3D simulations to separately visualize surface and body waves, relatively low and high frequency parts of the spectrum respectively, to correspond to the sounds that are given low- and high-pass filters. So the two renderings shown here are from the same seismic data and the same simulation, just filtered differently. Matt has been developing methods in “yt” to render complex migrating wave fronts, which is an interesting visualization problem. This is our first presentation of these movies, with lots of improvement to come. For best results, view the movie at full screen and use big headphones.