Youtor
>> YOUR LINK HERE: ___ http://youtube.com/watch?v=BBGmXsZHInw
More information on the USGS Multimedia Gallery: http://gallery.usgs.gov/videos/333 • • A caldera is a large, usually circular volcanic depression formed when magma is withdrawn or erupted from a shallow underground magma reservoir. It is often difficult to visualize how calderas form. This simple experiment using flour, a balloon, tubing, and a bicycle pump, provides a helpful visualization for caldera formation.
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