Nobody in the American midwest felt the massive magnitude 8 earthquake that shook the Solomon Islands, 7000 miles away, and sent a tsunami wave crashing into villages yesterday, but waves of seismic energy did travel through the ground below their feet, and a series of sudden ripples did move the whole country up and down several times before the tremor's vast energy faded away and died.
Those ripples were recorded in beautiful detail by a dense grid of seismic stations that has been migrating across the country since 2005, and currently spans a 300-mile wide belt that extents from Florida in the south to Minnesota and Michigan:
[You can watch a slightly more complicated version of the visualization, showing horizontal movement as well as vertical, here.]
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