CAS ES 351 Lecture Notes - Lecture 24: Last Glacial Maximum, Ocean Current, Laurentide Ice Sheet
22 Apr 2019
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Document Summary
The last glacial maximum (all glacial intervals basically) ended because of orbital changes where solar radiation increases during the summer in high latitudes in the northern hemisphere. ~this causes more melting of ice, and glaciers shrink. ~theres a lag between forcing and response (so peak solar radiation, 6,000 years alter we see minimum ice) Terminal morraines mark the farthest point a glacial goes out to. ~we can go to these, dig holes in the sediment, and measure the radiocarbon age (measure 14c ages in organic material) ~we go to the tropics to track glacial retreat because as sea level rises following maximum glaciation (melts), we get coral reefs built up around tropical islands. ~we can date the corals in regions that are tectonically stable and date when sea level was at a specific time (depth versus age plot) ~in the calcium carbonate, we will look at 14c (half life is really short, 6,000 years)
