|Dept:||Geological and Atmospheric Sciences|
Ph.D. Geosciences, University of Massachusetts Amherst, 2012
M.S. Geosciences, University of Massachusetts Amherst, 2006
B.S. Geology, University of Alaska Fairbanks, 2003
B.A., Photography, Hampshire College, 1997
Sea ice is a defining feature of our planet. It serves as habitat for some of the most spectacular animals on Earth—polar bears, walrus, and ice seals—as well as for some of the smallest primary producers: sea ice diatoms. The areal extent of summer Arctic sea ice is currently decreasing by more than 10% per decade, so it is a priority to understand the natural variability of ice extent and its relationship to the climate system. However, satellite data of sea ice only extends back to 1978, and observations of sea ice prior to the 1970s are sparse at best. My research uses marine sediments to explore how sea ice changed in the Bering and Chukchi seas in the past, particularly during periods of climate warming.
Some of the key questions my work addresses are:
• As the Earth went through glacial-interglacial cycles, did the growth and decline of sea ice lead or lag the growth and decline of ice sheets?
• Does sea ice duration decrease at a constant rate, or are there thresholds that lead to abrupt switches in sea ice duration (or extent)?
• During warming, are there periods of time that are characterized by re-advances of ice or does ice retreat in a linear fashion?
Google Scholar Profile
GEOL 101. Environmental Geology (spring 2013)
GEOL 102. History of the Earth (spring 2013, co-taught with Hasiuk)
GEOL 412X/512X. Micropaleontology
Caissie, B.E., Brigham‐Grette, J., Lawrence, K.T., Herbert, T.D., and Cook, M.S. 2010. Last Glacial Maximum to Holocene Sea Surface Conditions at Umnak Plateau, Bering Sea as Inferred from Diatom, Alkenone, and Stable Isotope Records. Paleoceanography, 25, 2008PA001671.
Takahashi, K.A., Ravelo, C., Alvarez Zarikian, C. and Exp. 323 Scientists. 2011. IODP Expedition 323—Pliocene and Pleistocene Paleoceanographic Changes in the Bering Sea. Scientific Drilling vol. 11, pp 4‐13.
Takahashi, K., Ravelo, A.C., Alvarez Zarikian, C.A., and Exp 323 Scientists. 2011. Proceedings of the Integrated Ocean Drilling Program, Volume 323: Tokyo.