GEOL 2207 Lecture Notes - Subduction, Oceanic Crust, Basalt
Document Summary
Risk: (vulnerability x hazard) / mitigation: hazard = size, frequency, type of damage, vulnerability = what is impacted and value, mitigation = 18146$ invested to reduce vulnerability or to control hazard. How do we study volcanoes: study and monitor active systems, forensic reconstruction. What is volcanology: structure where magma is erupted, includes erupted products, all shapes & sizes, diverse composition, subaerial & subaqueous. What is a volcanic system: source region. Mantle (periodotite) melting magma (basaltic granitic) Magma moves along cracks in the earth"s crust. Sill: horizontal intrusion of magma: storage region. Magma ponds below the earth"s surface in large chambers. Magma that freezes in crust and is not erupted = intrusive rock: eruption region. Cooled at surface: extrusive/volcanic, small crystals/fine grained, rapid cooling. Cooled below surface: intrusive/plutonic, large crystals/course grained, slow cooling. List the different categories of volcanic rocks and explain the differences between the magmas they came from.
