Red spheres represent earthquake epicenters, as reported by the USGS,
with smallest magnitudes.
Orange spheres represent earthquake epicenters,
as reported by the USGS, with magnitudes betwee the smallest and
largest magnitudes.
Purple spheres represent earthquake epicenters, as
reported by the USGS, with largest magnitudes.
Drag mouse to rotate model. Use mouse wheel or middle button
to zoom it.