Week 8 summary Flashcards
What does the LGM mark?
period of maximum ice extent and coldest temperatures
during the last glacial period
When is the LGM centered?
~21,000 years BP
Where did the most dramatic changes occur?
most dramatic changes were in regions closest to and most directly influenced by the ice sheets
How much of the land’s surface was covered by ice?
Ice covered 25% of Earth’s land surface.
Where were large ice sheets during the LGM?
Large ice sheets were present over North America, Northern Europe, Russia, Antarctica and Greenland
What were sea levels during the LGM?
Sea levels were 110-125 m lower than today
What were global temperatures during LGM?
3-8 °C cooler than today
What was greenland temperature during LGM?
21-25 °C cooler
What was the climate during the LGM?
climate was drier and dustier
What did the different climate in the LGM cause?
deposition of loess fields
expansion of desert and sand dune regions
Forest cover contracted
tundra and grassland covered high latitude regions
What was deglaciation initially driven by?
increase in NH summer insolation, and enhanced by CO2 and ice-albedo feedbacks
What happened during degalciation?
continental ice melted,
sea level rose,
world became warmer and wetter.
When did the fastest rates of warming occur?
during the Bølling Allerød in Greenland (14,500 years ago)
What was occuring at the same time as the Bølling Allerød?
the Antarctic Cold Reversal was occurring
What interrupted the warming of the Northern hemisphere?
the Younger Dryas
