Beth Caissie

Assistant Professor [GE AT]
Dept:Geological And Atmospheric Sciences
Office:153 Science
2237 Osborn Dr
Ames IA

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

I am most interested in using periods when the Earth warmed in the past as analogs for what might happen in the future as our planet's climate continues to change. In particular, I'd like to know what happens to sea ice as climate warms. Does it retreat quickly or slowly? Does it retreat at the same time as the massive ice sheets and glaciers on land did? Or does it persist long after those ice sheets have melted? What happens to the algae and primary producers that live in or near sea ice? Do the species in these communities change quickly? Does productivity increase when the ice disappears? Or is it higher when seasonal ice is present?

My research is focused on the subarctic Pacific region-the Bering and Chukchi seas, the Gulf of Alaska, and the North Pacific-because this region has seasonal sea ice today or in the past. I use sediment cores to reconstruct sea ice and primary productivity. Specifically, I look at and identify the microfossils, such as diatoms, present in sediment cores. I quantify the grain size in sediment cores to look for particles transported by ice, and I use carbon and nitrogen isotopes to determine whether marine or terrigenous organic matter is more prevalent at various times.

Please visit my lab page, the Marine Sediments Lab, to find out more about the types of projects my students and I have been working on lately.

Google Scholar Profile

GEOL 101. Environmental Geology (spring)
GEOL 102. History of the Earth (spring, co-taught with Dr. Franek Hasiuk)
GEOL 412X/512X. Micropaleontology (even falls)
GEOL 590N. Oceans Seminar (odd falls)

Selected Publications

Vaughn, D.R. and Caissie, B.E., 2017. Effects of sea-level, sea-ice extent and nutrient availability on primary production at the Umnak Plateau, Bering Sea (IODP Site U1339) during Marine Isotope Stage (MIS) 5. Palaeogeography, Palaeoclimatology, Palaeoecology,

Caissie, B. E., Brigham-Grette, J., Cook, M. S., and Colmenero-Hidalgo, E. 2016. Bering Sea surface water conditions during Marine Isotope Stages 12 to 10 at Navarin Canyon (IODP Site U1345). Climate of the Past 12, 1739-1763,

Weckström, K., Miettinen, A., Caissie, B.E., Pearce, C., Ellegaard, M., Krawczyk, D., and Witkowski, A., 2014. Sea surface temperatures in Disko Bay during the Little Ice Age – Caution needs to be exercised before assigning Thalassiosira kushirensis resting spore as a warm-water indicator in palaeoceanographic studies. Comment on: Late-Holocene diatom derived seasonal variability in hydrological conditions off Disko Bay, West Greenland by Diana W. Krawczyk, Andrzej Witkowski, Jeremy Lloyd, Matthias Moros, Jan Harff and Antoon Kuijpers. Quaternary Science Reviews 101, 234-237.

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.