Originally published on July 19, 2013 <br /><br />Scientists at the University of Washington have discovered what they have dubbed a 'seismic scream' that precedes explosive volcanic eruptions. Readings taken from Alaska's Redoubt volcano prior to a 2009 eruption recorded a series of tremors around 2km below the crater. This swarm of 1,600 or so 'drumbeat' earthquakes took place in the ten hours before the first explosion.<br /><br />The tremors then increased steadily in frequency and occurrence, eventually blurring into a continuous stream. The noise peaked around 30 seconds before the eruption.<br />The scientists believe the sounds are caused by the rapid slipping of many small faults near the conduits of molten magma as pressure builds up ahead of the eruption.<br /><br />--------------------------------------------------------<br /><br />TomoNews is your daily source for top animated news. We've combined animation and video footage with a snarky personality to bring you the biggest and best stories from around the world. <br /><br />For news that's fun and never boring, visit our channel:<br />https://www.youtube.com/user/TomoNewsUS<br /><br />Subscribe to stay updated on all the top stories:<br />http://www.youtube.com/subscription_center?add_user=TomoNewsUS<br /><br />Stay connected with us here:<br />Facebook http://www.facebook.com/TomoNewsUS<br />Twitter @tomonewsus http://www.twitter.com/TomoNewsUS<br />Google+ http://gplus.to/TomoNewsUS
