Spring 2021

Julie Brigham-Grette

Speaker:

Julie Brigham-Grette
University of Massachusetts
2020 Distinguished Lecturer of the Continental Scientific Drilling Division of the Geological Society of America

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.


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