Cheyenne Everhart

Mentor: Dr. Ellen Martin
College of Liberal Arts and Sciences
 
"Research was a great opportunity to apply the knowledge and skills learned in my geology course work in a scientific investigation that interested me."

Major

Geology

Minor

N/A

Research Interests

  • Geochemistry
  • Global Climate Change

Academic Awards

  • N/A

Organizations

  • Sigma Gamma Epsilon Geology Honors Society
  • Theatre Strike Force
  • Geology Club

Volunteer

  • Can You Dig It? Museum Outreach

Hobbies and Interests

  • Improv Comedy
  • Intersectional Feminism
  • Live music

Research Description

Rates of Weathering in the Deglaciated Area in Western Greenland
Seawater Pb isotopes preserved in North Atlantic marine sediments increase rapidly across the last deglaciation (20-8 ka). This increase is believed to reflect incongruent chemical weathering of freshly exposed, glacially comminuted sediment, whereby radiogenic Pb isotopes are preferentially released from accessory phases. These glacially derived sediments weather faster than the global average and produce fluxes of radiogenic isotopes that reflect weathering rate and intensity. Melting of the Greenland Ice Sheet (GrIS) progressively exposes deglaciated watersheds on the continent, but little work has been done to characterize weathering in these regions. Dr. Ellen and Jon Martin have an ongoing funded research project studying weathering in the deglaciated portion of Western Greenland. Preliminary work on the Western Greenland samples demonstrated that weathering solutes in the watersheds on younger moraines (~7,000 yrs) close to the ice sheet are dominated by calcite weathering products and there are large offsets between the Sr isotopes of the stream waters and bedload samples, suggesting highly incongruent weathering. In contrast, solute geochemistry in the coastal watersheds on older moraines (~10,000 yrs) indicate a greater contribution from silicate weathering and a smaller offset between the Sr isotopes in the waters and sediments, suggesting more congruent weathering. I plan to test our current interpretation of the weathering regimes in coastal and inland regions by running experiments on moraine material from these two areas. Through my research I will analyze moraine samples from a transect of deglaciated watersheds in western Greenland spanning 150 km from the edge of the modern GrIS to the coast for Sr and Pb radiogenic isotopes.