ERS120H5 Lecture Notes - Lecture 10: Pumice, Pyroclastic Flow, Cascade Range
Document Summary
Composition is the same, but the temperature is different. Composition and temperature play a role in viscosity (how it behaves) Volcanoes tend to fall around plate boundaries (along subduction zones) Big eruption, less frequently) (i. e. redoubt volcano, kenai peninsula) Answer: b. magma associated with an eruptive eruption, Effusive (a lot of lava, trickling out). High viscosity, magma"s blocking effect leads to explosive reaction. Generally, dark in colour to light in colour (as you go down) Effusive: lower viscosity, mafic, crystallizes first, high melting temperature. Eruptive higher viscosity, silicic, crystallizes last, low melting temperature. Strato eruptive: sticky, closer to core. Almost always lava coming to the surface. Cold (high elevation) at the top of the mountains. Flank eruption a little fracture will open up, narrow foundation of lava come out of cracks and produce lapilli (little drops of lava) and pele"s hair (long fiber of volcanic glass that looks like hair).
