when volcanoes erupt pg. 115. what are non explosive eruptions? volcanoes that erupt only lava and...
TRANSCRIPT
When Volcanoes Erupt PG. 115
What are non explosive eruptions?
Volcanoes that erupt only lava and gas
The most common type of eruption
What erupts from a volcano?
1. Lava-- 4 types
Pahoehoe
Flows slowly, smooth glassy surface A’a—pours out quickly, brittle
jagged surface
Pillow lava—lava that erupts under water
Blocky lava—sharp edged chunks of stiff lava
What are explosive eruptions?
Clouds of hot rock, ash and gas rapidly shoot out from the volcano
Millions of tons blast out in a few seconds
2. Pyroclastic material
4 types of material
Bombs—large blobs of magma that harden when they fly through the air
Blocks—largest pieces of solid rock blown away from the volcano
3. Lapilli—little stones of magma that harden before they hit the ground
4. Volcanic ash– magma explodes into tiny glass like slivers
What are pyroclastic flows?
Enormous amounts of hot ash, dust and gas are ejected from a volcano
Races downhill at more than 200 km / hr
Temperatures can exceed 700 degrees C
What are the effects of volcanic eruptions?
Climate can be changed as ash and gas spread throughout the atmosphere
Eruptions can affect the whole Earth with lower temperatures
Mt. Vesuvius and Pompeii
What are other types of Volcanic Landforms? 3 types
1. Craters
The central funnel shaped vent at the top of a volcanoA
2. Calderas
Many times larger than a crater
A semicircular depression that forms when the magma chamber partly empties and causes the ground above to sink
3. Lava Plateaus
A wide flat area caused by repeated nonexplosive eruptions of lava that spread over a large area