Evolution of the Earth
Volcanoes and hotspots
Reconstruction of the Earth’s history
Volcanoes are the result of hot spots within the crust or mantle of the earth.
The hot, liquid rock will break through weak spots in the surface and form volcanoes or flood basalts.
Many volcanoes do not release lava, instead they spit ash and small bits of lava called lapilli.
Some eruptions are quiet with very fluid (low viscosity) lava flows while others are explosive
Mt. St. Helen before the explosive eruption
Time lapse of the eruption
Mt. St. Helen after the eruption
Mt. St. Helens begins the rebuilding process
Basalt is a type of rock that is
produced from the mantle