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Project Hypothesis or Objectives:
Peatlands store roughly one-third of the world’s soil carbon and are thought to have been major contributors to changes in atmospheric carbon dioxide and methane concentrations on glacial and interglacial timescales. However, questions remain about the climate conditions that promoted their expansion and accumulation in the Holocene. Many peatlands, particularly those in boreal regions, are becoming more vulnerable to disturbances from fire and permafrost thaw, but also respond to more subtle changes in temperature and hydrology. This study aims to use peat cellulose oxygen isotopes to examine hydroclimate variability over the Holocene. In addition to analysis of physical peat properties, we will use peat cores from Alaska to interpret past hydroclimate regimes of the North Pacific, using a combination of plant macrofossils and stable oxygen isotopes derived from peat cellulose. The plant macrofossils, especially bryophytes, provide information about past water table position and the degree of groundwater input to a site. The stable isotopes will help constrain source-water changes through time, including variation in large-scale circulation over the Holocene. Placing these changes into the larger regional context will help elucidate patterns of past North Pacific climate variability and also provide information about how peatland carbon dynamics shifted as a result.
The goal is to build on growing understanding of the plant-cellulose oxygen isotope proxy to interpret North Pacific paleoclimate. The internship will expand the intern’s skillset in a laboratory setting, by allowing him/her to actively participate in the peat core analysis and cellulose extraction analysis. Furthermore, interpretation of these records will lead to a publication, which we intend the intern to lead or co-lead.
Duration: Up to 12 months
Internship Location: Reston, VA
Keywords: Chemistry/Geochemistry, Climate Change, Ecology/Ecosystems, Hydrology, Paleoclimatology, Wetlands
Applicable NSF Division: GEO (Atmospheric, Earth Sciences, Ocean Sciences, Polar Programs), BIO (Environmental Biology, Molecular & Cellular Biosciences, Biological Infrastructure, Integrative Organismal Systems)
Intern Type Preference: Any Type of Intern
Duties/Responsibilities:
The intern will have access to USGS laboratories, where s/he will perform a variety of analyses, ranging from macrofossils to cellulose extraction. Our labs are equipped with elemental analyzers, drying ovens, furnaces, freeze driers, microbalances, microscopes, to name a few. Other labs that potentially could also work in conjunction with this project are palynology and physical property labs. The intern will also be able to experience what research at the USGS looks like.
Expected Outcome:
The expected outcome is at least one peer-reviewed publication, led or co-led by the intern, which will not only benefit the intern but also the USGS. The intern will gain valuable career development experience, new skills in a laboratory setting,
Special skills/training Required:
Mandatory skills are prior laboratory experience, attention to detail, and a strong work ethic. Other skills can be acquired during the internship.
