Some Volcanoes 'Scream' at Ever-Higher Pitches Until They Blow Their Tops
Sunday, July 14, 2013 - 12:30
in Earth & Climate
Swarms of small earthquakes can precede a volcanic eruption, sometimes resulting in "harmonic tremor" resembling sound from some musical instruments. A new analysis shows tremor during a 2009 sequence at Alaska's Redoubt Volcano glided to substantially higher frequencies, then stopped abruptly just before six of the eruptions.