CAS ES 351 Lecture Notes - Lecture 22: Last Glacial Maximum, Ice Core, Oxygen-18
8 Apr 2019
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Termination abrupt increase in co2 and decrease in 18o. Ice cores should be drilled right in the center (vostok) Ice cores are dated by a combination of layer counting and flow modeling. There is liquid water at the bottom of vostok (called lake vostok) because of geothermal heat and a huge layer of an ice blanket on top of it. People put antifreeze inside the core to ill it after the ice core was taken out. We get this information from an ice core: air samples (concentration of co2 and methane) and the ice itself (made of h2o, you can measure the delta 18o of water, so thus temperature and hydrogen) Firn is right at the surface (old snow on its way to becoming ice) At some depth, about 50 meters of snow (this takes hundreds of years) is looses its permeability and becomes ice.
