Date:
Tuesday, February 13, 2018, 3:00pm
Location:
Seminar Room MCZ, 429
Speaker: Judy Pu
Judy will lead the discussion on the Snowball Earth climate dynamics and Cryogenian and she lead us through the following key points:
- Geological evidence shows that ice from polar regions reached equatorial latitudes at least twice in Earth history during the Cryogenian Period (720-635 Ma).
- High-precision geochronology, paleomagnetism, and climate modeling support globally synchronous deglaciation for both snowball periods, but onset age and duration of the later Marinoan snowball Earth remain unclear.
- The snowball Earth periods were times of dynamic glaciers and ice sheets in a cold and dry climate state, with possible reversal of the annual mean tropical atmospheric circulation.
- Trigger mechanisms and reasons for the drastic difference in duration between the two Cryogenian snowball Earth events are still uncertain.
hoffman_etal_sciad_2017.pdf | 7.08 MB |