Weak spot in the Earth's crust where magma rises to the surface
The low velocity of lava flows means that the skin that forms by air-cooling is not disrupted during flow and can maintain its smooth, unbroken, well-insulating surface. Shapes vary.
Mixture of melted rock and gases on the surface of earth
large, bowl-shaped cavity at the top of a volcano
Mixture of melted rock and gases below Earth's surface
lava that forms when lava flows rapidly. Under these circumstances, there is rapid heat loss and a resulting increase in viscosity. When the solid surface crust is torn by flow, the underlying lava is unable to move sufficiently rapidly to heal the tear. Bits of the crust are then tumbled in and coated by still liquid lava, forming the chunks.
smaller opening where magma leaves volcano
Tube that connects magma chamber to Earth's surface
hot, fast-moving cloud of ash and cinder
Giant chunk of magma thrown out of a volcano
Pocket where magma collects
String of islands created by volcanoes near plate boundaries
area where material from deep within the mantle rises then melts, forming magma, and a volcano on top
magma flows easily and quietly - contains pahoehoe and aa
not active but may become active
magma builds up pressure and explodes creating pyroclastic flows and magma bombs
unlikely to erupt again
tall, cone-shaped mountains in which layers of lava alternate with layers of ash
volcanic mud flow
Volcanic Activity Measuring Equipment
seismograph, GPS, gas spectrometer, satellites. key ingredients are seismic monitoring, gas monitoring, and deformation studies.
a small volcano built primarily of pyroclastic material ejected from a single vent
a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions
raised mound of hardened lava, formed form magma pushing up from under the surface
bits of rock or solidified lava dropped from the air
sheets of lava that flow onto the ground surface and bury or burn everything in their path
are caused by magma chambers filling up and causing the ground to swell
Flickr Creative Commons Images
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