Associate Professor of Earth Science
Peer Online Course Review (POCR) Lead
Heather Kokorowski
Graduate Research
University of Washington
My graduate research at the University of Washington (UW) involved reconstructing past climatic conditions from various proxies in lake sediment cores as a means to better understand and predict the possible nature and mechanisms of future change.
Master's Thesis in Geological Sciences
"Oxygen isotopes recorded in lacustrine diatoms from southwestern Greenland: First results based on a laser fluorination method"
This research involved using an innovative geochemical proxy (diatom silica delta-18O) from near-surface sediments of a previously unstudied lake to reconstruct changes in temperature and atmospheric circulation patterns (i.e., storm tracks) in western Greenland during the Late Holocene. I conducted two summers of fieldwork in Greenland and spent four months in Germany working in collaboration with the Alfred Wagener Institute for Polar and Marine Research (AWI) to develop an experimental new method to measure the isotopic composition of silica-bound oxygen. This research was largely unfunded, compelling me to act as a teaching assistant (TA) for several courses at the UW. It was through these TA appointments that I discovered my passion for teaching!
Master's Thesis in Ecosystems Analysis
"A multi-proxy investigation for the Younger Dryas at Elikchan 4 Lake, northeastern Siberia, and implications for its spatial distribution in Beringia"
This work focused on reconstructing the climatic history of northeastern Siberia based on a multi-proxy sediment record, and comparing climatic changes in the North Pacific to those in the North Atlantic. I collaborated with a team of international researchers and conducted laboratory and fieldwork in northeastern Siberia. It was through this research that I truly began to embrace an interdisciplinary approach to science, and learned the immense value of balancing classroom, laboratory and field study.
Graduate Research Assistantships
As a graduate student, I worked as a research assistant on several laboratory and field projects. In the field, I worked in Thule, northwestern Greenland, to assess high arctic biocomplexity issues such as hydrology, carbon storage, CO2 flux, water content, and soil formation. Duties included measuring river discharge, pH, and conductivity to assess rates of melting of the Greenland Ice Sheet, collecting soil water, soil CO2, precipitation, and snow samples, digging pits for carbon analysis, assisting in describing, mapping and sampling different soil horizons, assisting in measuring and describing solufluction lobes, and planning and executing a 3-week field season near Kangerlussuaq, southwest Greenland. Laboratory duties included filtering water samples for isotopic analysis, analyzing soil water, precipitation, and stream samples for water chemistry using an inductively-coupled argon optical emission spectrometer (ICP-OES), extracting elements (specifically Pb, Cd, Zn) from a diffusion study in frozen sand columns to simulate heavy metal dispersion in permafrost soils, and measuring concentrations with an ICP-OES.
I also worked at Elikchan 4 Lake and the North East Interdisciplinary Science Research Institute in Magadan, northeastern Siberia, to collect lacustrine sediment cores for paleoclimatic reconstructions. Field duties also included collecting soil, water, algae, and terrestrial and aquatic plant samples, operating a plant press, conducting plankton tows and seismic profiling of the lake bottom, and transporting supplies and samples internationally. Laboratory duties included describing and photographing lacustrine sediment cores, fine-scale sampling of sediment cores at 0.25 cm increments, taking subsamples for various analyses, physically and chemically preparing pollen samples for identification, extracting pollen concentrates from bulk sediment, preparing pollen concentrates, bulk sediment, and macrofossils for AMS 14C dating, measuring sediment magnetic susceptibility, grain-size, organic carbon content (loss-on-ignition and coulometric methods), and biogenic silica content in a diatom-rich lake.
Undergraduate Research
University of Arizona
When I entered the University of Arizona as an undergraduate, I initially chose biochemistry as a major, and had aspirations to become a medical doctor. I began working as a research assistant studying the uptake of lipids by insect oocytes. While I found these studies interesting, I soon realized that the research did not engage me. I discovered what was missing in an introductory biology class during my sophomore year. A short unit on environmental biology fascinated me as I instantly recognized a connection between environmental sciences and the real world, an essential link that was missing in my studies of insect microbiology. I changed my major to Ecology and Evolutionary Biology and began working in a paleolimnology laboratory studying the ecological effects of recent human habitation along the shores of Lake Tanganyika, East Africa. Here, in sediment accumulating at the bottom of a lake, was the ‘big picture’ I had been longing for!
Undergraduate Honor's Thesis
Geosciences
"A paleolimnological study of lacustrine-deltaic sediments at Lake Tanganyika, Africa: Implications for the effects of human habitation"
This work involved subsampling sediment cores from Lake Tanganyika, measuring sediment organic and inorganic carbon content (loss-on-ignition method), sieving sediment, identifying and describing ca. 50 species of fossil ostracodes and counting sponge spicules. For my Honor's Thesis, I analyzed how sediment characteristics and ostracode abundance and diversity changed over the past few hundred years in response to natural factors and human activities along the shores of the lake. Following two years of this laboratory research, I had the opportunity to spend a summer in Tanzania as a participant of the Nyanza Project, a research training program for undergraduate and graduate students and secondary school teachers to conduct field research on Lake Tanganyika and to analyze, write and present research results. There, I was able to directly observe and analyze how recent human activities along the shores of the lake have impacted surrounding ecosystems.
