ASTR 5 Lecture Notes - Lecture 3: San Andreas Fault, Continental Crust, Plate Tectonics
Document Summary
We take for granted most of qualities that make earth habitable; our neighbors prove how rare these qualities are: Moderate temperature, abundant water, protective atmosphere , and stable environment. Hotter than a pizza oven, 90 earth"s pressure, volcanoes, few craters. Frigid, very thin co2 atmosphere; desert land with craters and frozen ice caps. Craters show that nothing has molded landscape for a long time. Study of the formation and evolution of worlds. Volcanism : releases trapped heat, gas, and material from within. Plate tectonics : reshapes earth and regulates climate. Global magnetic field : acts as barrier and mitigates loss of atmosphere from solar wind. Geological record : rocks and fossils that give us information about earth"s age. Fossils : relics of organisms that died long ago. Metamorphic : structurally / chemically transformed by high pressure or heat (not enough to melt) Sedimentary : gradual compression of sand and silt at bottom of seas and swamps.
