Spring 2021
| Speaker: |
Julie Brigham-Grette |
| Title: | The Impact of Lake El鈥檊ygytgyn, NE Russia, on our Knowledge of Polar Climate: this changes everything |
| Date: | February 12, 2021 |
| Time: | 11:45am |
| Location: | Contact instructor for details. jemezger@alaska.edu |
成人影片:
Dr. Brigham-Grette is a leading expert in Arctic environmental change. She has been
conducting research in the Arctic for 40+ years, including eight field seasons in
remote parts of northeast Russia. Julie served as a postdoctoral fellow in Bergen
Norway and at the University of Alberta before taking a faculty position at the University
of Massachusetts-Amherst. She is an elected Fellow of the Geological Society of America
and the American Geophysical Union, and President of the Quaternary Geology & Geomorphology
Division of GSA. Julie鈥檚 research expertise is in marine and terrestrial sediment
records of Arctic climate change over the last few million years. She led the International
Continental Scientific Drilling Program at Lake El鈥檊ygytgyn in NE Russia collecting
a record of Arctic change over the past 3.6 million years and has strong interests
in public engagement, using science to inform policy on coastal management challenges
with rising sea level.
Abstract:
Lake El鈥檊ygytgyn was formed by a large meteorite impact in NE Russia about 3.6 Million
years ago during the warm middle Pliocene. Scientific drilling in 2009 into a frozen
ice covered lake without any road infrastructure was logistically challenging, yet
the project recovered a continuous paleoclimate sediment record (318 m) and impact
suevites (200m) through grit, and international collaboration between in Russia, USA,
Germany, and Austria. The Lake El鈥檊ygytgyn record provides the first impressions we
have of how the Arctic borderlands evolved from forested landscapes and sea-ice free
summers during the Pliocene to an Arctic of warm interglacial and cold glacial cycles
in recent time. We discovered evidence for over a dozen Arctic super 鈥渋nterglacials,
i.e., natural warm periods, that were warmer than most warm periods of the past 3.6
million years. Some warmer periods can be linked to times when the Greenland Ice Sheet
and possibly the West Antarctic Ice Sheet were dramatically smaller with serious implications
for global sea level. Overall, we have gained new knowledge about the remarkable sensitivity
of the Arctic to even small atmospheric forcings caused by climate change. This sensitivity
gives us predictive scientific tools for better forecasting into the near future how
the Arctic regions will respond to the anthropogenic warming now taking place.
Passcode: &JD2Y3#T