GEL 1 Lecture Notes - Lecture 23: Olympic National Park, Grinnell Glacier, Last Glacial Maximum
graph: geological time and average temperature variations
●cold periods of time: icehouse phases
●warm periods: greenhouse phases
●general trend over the last 100 mil years
○temperatures have been decreasing
○atmospheric CO2 as well
○modern avg temp : 15 C (59 F)
○Mid-Cretaceous : 23 C (73 F)
●paleoclimatology: the study of Earth's past climate
Glaciers are the largest source of freshwater
Glaciers +Ice Sheets = storage of water out of oceans
2 Types of Glaciers
●Valley Glaciers
○more numerous today
○smaller total volume
○found in valleys at high latitude or high altitude
●Continental Glaciers / Ice Sheets
○significantly smaller today than at Last Glacial Maximum
■period of time where there were much more significant glaciers on
continental land masses
○Greenland and Antarctica are the two big ones we have today
Broad categories
●Type of glacier → leaves behind specific sedimentary deposits and evidence
Agents of Erosion: Glaciers
●Valley Glaciers
○flow down a valley
○length much greater than width
○eg Alaska, Alps, Himalayas, Canada
○glaciers are receding
■Anderson Glacier in Olympic National Park, Grinnell Glacier from Glacier
National Park, Patagonia in Argentina, McCarty glacier in Alaska, Mt
Kilimanjaro
■more melting than there is accumulation
■"shrink uphill"
■glacial river makes it melt even more, from the bottom
Document Summary
General trend over the last (cid:270)(cid:269)(cid:269) mil years. Modern avg temp : (cid:270)5 2 (cid:354)59 f(cid:355) Paleoclimatology: the study of earth"s past climate. Glaciers +ice sheets = storage of water out of oceans (cid:271) types of glaciers. Found in valleys at high latitude or high altitude. Significantly smaller today than at last glacial maximum. Period of time where there were much more significant glaciers on continental land masses. Greenland and antarctica are the two big ones we have today. Type of glacier leaves behind specific sedimentary deposits and evidence. Anderson glacier in olympic national park, grinnell glacier from glacier. National park, patagonia in argentina, mc2arty glacier in alaska, mt. Glacial river makes it melt even more, from the bottom. Decrease in sea ice area at the north pole is greater than the area of 2alifornia and. Overall long-lived (cid:354)5+ yr(cid:355) ice is decreasing and arctic ice. Opening up sea way between pacific and atlantic.
