Posted on May 12, 2022
Bluish white filtered from the wall structure of an Antarctic snow gap illuminates “Put,” the latest mascot having Tuckahoe Primary School into the Henrico County, Virginia. On wall structure of the pit, dark and white bands off reduced compressed snowfall identify snow transferred regarding winter season away from accumulated snow placed in the summer. (Photograph through Christopher Shuman, NASA GSFC)
So you’re able to pry weather clues out of the frost, boffins started initially to exercise enough time cores out from the frost sheet sets into the Greenland and you may Antarctica regarding the later 1960s. By the point Alley and the GISP2 enterprise completed in the latest early 1990s, they’d pulled an almost dos-mile-enough time key (step 3, meters) on Greenland ice sheet, taking an eye on no less than going back 110,000 many years. Actually older suggestions going back regarding 750,100000 decades have already come out out of Antarctica. Boffins have also pulled cores regarding thick mountain glaciers during the metropolitan areas including the Andes Slopes from inside the Peru and you may Bolivia, Install Kilimanjaro during the Tanzania, and the Himalayas when you look at the China.
Apparently young and low snow will get packaged into rough and you will granular crystals called firn (top: 53 yards deep). Towards the bottom away from a core (lower: step 3,050 meters), stones, sand, and you may silt discolor the latest frost. (Pictures courtesy You.S. (more…)