Current Projects of the Sedimentary Records of Environmental Change lab  

Measuring biogenic silica content of lake sediments from Scandinavia to investigate warm and cold periods during the last deglaciation.  Biogenic silica analyses provides a measure of lake productivity. Lake productivity is controlled, in part by climate.  To learn more about this project, ARCTREC, visit http://www.bccr.no/arctrec/default.asp?kat=22&sp=1. 

Investigating storm-track changes in the North Pacific region over the past several thousand years using the oxygen-isotope composition of diatoms extracted from lake sediment. Changes in the strength and position of the Aleutian Low influence the storm tracks that intersect south Alaska. A current hypothesis is that these changes are recorded in the oxygen isotopes ratios of diatoms which incorporate oxygen from precipition into their silica structure during formation.

Quantifying summer temperature fluctuations during the last several thousand years using the concentration of sedimentary algae (biogenic silica) from arctic, sub-arctic, and alpine lakes.  Much of the analyses completed in our lab will be incorporated into a special volume for the Journal of Paleolimnology.  The special volume is one product of the 2000 Years of Climate Variability from Arctic Lakes project. 

Reconstructing the hydrogeographic and climatologic changes at Bear Lake, Utah-Idaho, using the oxygen-isotope composition of carbonate from a continuous sediment core extending back 250,000 years. Visit the project website for more information: http://esp.cr.usgs.gov/info/lacs/ or read a recent publication.

Using ostracode species assemblages to reconstruct the environmental conditions of pluvial lakes in the Mojave Desert during the last ice age.  Visit the project website for more information: http://esp.cr.usgs.gov/info/mojave/paleoenviron.html 

Assessing the frequency of eruptions from Aleutian Arc volcanoes using ash deposits and other features preserved in lake sediment from southern Alaska. Holocene tephra-fall records have been obtained from the base of Mt. Redoubt and from lakes on the Kenai Peninsula.  This summer, we will return to a lake at the base of Iliamna Volcano to recover sediment cores from the volcano-proximal site.