EESA06H3 Lecture Notes - Lecture 2: Supercontinent, Seafloor Spreading, Subduction
28 May 2017
School
Department
Course
Professor
Document Summary
Uplift: we"re all getting taller every year b/c of this. North america was sat on an ice plate which presses the continent down by 100s of meters, they melt disappear and the crust rebounds from the bend. Centre of next supercontinent is in east asia. Mountain ranges are created when 2 plates are pushed together. Heat builds up under forming continent, causing landmass to rise and there"ll be new continent (superc splits)". Thin areas of rock (40-70 km thick) and their response to convection in the earth"s mantle. Figure 1: plume (red), that experiences decompression melting pushes existing magma apart by intruding important b/c it"s the process behind sea floor spreading. Oceanic plates underlie oceanic basins & made out of specific rock (basalt). High density b/c composed of fe & mg high density and wants to sink. Subduction zone: to push a plate under another tsunamis and other disasters.
