Allyson Tessin
(Photo provided by Allyson Tessin)

I am a geologist and biogeochemist. I study how ocean chemistry changes through time. My research is motivated by the need to accurately predict how human-caused climate change will affect ocean carbon and nutrient cycles in the future. My work combines field geology and shipboard science to study how oceans have changed in the past and are changing in the present.

I completed my bachelors’ degrees at the University of Pittsburgh and PhD at the University of Michigan. I am interested in Arctic environmental change as this region is rapidly changing in response to anthropogenic climate change. Understanding how these changes will affect marine chemistry has important implications for the ocean’s carbon cycle, marine productivity, and the health of economically important fisheries.

I am currently a visiting research fellow at the University of Leeds after completing a Marie Curie Independent Research Fellowship this fall. My work at Leeds focuses on the chemical and biological changes occurring in response to retreating sea ice in the fragile Arctic Ocean. I have been on three recent research cruises to the Barents Sea to sample mud and water in order to document rapid changes occurring within the ocean seafloor environment. In addition to modern observations, my studies buried sediments to reconstruct changes that occurred in the Arctic Ocean at the end of the last ice age.

You can follow my Arctic adventures on Twitter @allyson_tessin and read more about her research at I can be reached by email at

Some of my publications include:

Tessin, Allyson., T.S. Bianchi, N.D. Sheldon, I. Hendy, J.A. Hutchings, and T.E. Arnold. 2017. “Organic matter source and thermal maturity within the Late Cretaceous Niobrara Formation, US Western Interior.” Marine and Petroleum Geology. (86): 812-822. DOI: 10.1016/j.marpetgeo.2017.06.041.

Tessin, A., Nathan D. Sheldon, Ingrid Hendy, and Anthony Chappaz. 2016. “Iron limitation in the Western Interior Seaway during the Late Cretaceous OAE 3 and its role in phosphorus recycling and enhanced organic matter preservation.” Earth and Planetary Science Letters (449): 135-144. DOI: 10.1016/j.epsl.2016.05.043.

​Tessin, Allyson., Ingrid Hendy, Nathan Sheldon, and Bradley Sageman. 2015. “Redox controlled preservation of organic matter during “OAE 3” within the Western Interior Seaway.” Paleoceanography 30(6):702-717. DOI: 10.1002/2014PA002729.