Transcript:  Crater_Glacier Time-Lapse Video

[Text] USGS, Science for a Changing World.

[Text] Mount St. Helens, Crater Glacier, 2005-2010.

[Text] A remote camera on the northwest flank of Mount St. Helens captured hourly photographs of volcanic dome growth during the 2004-2008 eruption.  The photos also captured the response of Crater Glacier as it moved across the crater floor.

[Image] Image looking into the crater of Mount St. Helens (November, 2005) from remote camera location.  Text indicates the location of the 1980-1986 dome with an orange line highlighting the top of the dome.  Text indicates the location of the 2004-2008 dome with an orange line highlighting the top of the dome.  Text indicates the location of Crater Glacier with an arrow showing the direction of glacier advance.

[Video] Video shows the 2004-2008 lava dome building upward and toward the northwest.  Crater Glacier is compressed and bulges upward.  The glacier advances rapidly to the north (downhill and to the left in the video).  Ice surface deformation occurs.  The camera angle changes in 2007 to a wider view.  The time lapse shows seasonal changes from snow cover (winter) to bare ground (summer).  Small streams of water are observed flowing from the glacier wall.  The glacier continues to advance to the northeast (to the left of the video frame) until the video concludes.

[Image] Image looking into the crater of Mount St. Helens (November 2010) from remote camera location.  Text indicates the location of the 1980-1986 dome with an orange line highlighting the top of the dome.  Text indicates the locations of the 2004-2008 dome with an orange line highlighting the top of the dome.  Text indicates the locations of the west and east arms of Crater Glacier with arrows showing the direction of glacier advance.

[Text] The growing lava dome pushed the glacier against the crater walls.  Compression and stacking of the ice resulted in rapid glacial advance.  The east and west arms of the glacier connected in 2008, encircling the 1980-1986 dome.  Glacial advance has slowed since the eruption ended in 2008 but the glacier continues to move across the crater floor.

[Text] For more information about Mount St. Helens, visit the U.S. Geological Survey-Cascades Volcano Observatory website http://volcanoes.usgs.gov/observatories/cvo.  This video (855 images, 30 frames per second) is an uneven time sequence for winter months when periods of cloudy weather obscured the view into the crater.  Video Team:  Dan Dzurisin, Carolyn Driedger, Liz Westby.