article_snippet.sent: Above, a map from the United States Geological Survey predicts the amount of ash from the blast .
article_snippet.sent: the blast would then unleash  feet of volcanic ash over all of the United States.
article_snippet.sent: Above, devastation after the 2011 tsunami that hit Japan .
highlights_snippet.sent: Seismic activity would trigger volcano, pour feet of ash over the US .
  