USGS Contributions to the Climate Change Science Program

Sampling of deposits (bogs, lakes, and natural exposures) that contain fossil pollen, plant macrofossils, and sometimes ostracodes and diatoms allows reconstruction of the late Pleistocene and Holocene history of environmental change in southern Alaska, focusing upon the past 50,000 years. High-latitude ecosystems are highly sensitive to climatic change, and therefore understanding their history of environmental responses to past climate changes provides not only information about those past responses but also provides a basis for predicting future responses to a variety of possible climatic scenarios. So far the project has focused upon the late Quaternary history of Tongass National Forest in southeastern Alaska, Chugach National Forest, and adjacent areas of south-central Alaska, and Western Alaska.

Coring lake sediments in Cavern Lake, Tongass National Forest, southeastern Alaska.

USGS climate researchers core lake sediments at Zagoskin Lake, Saint Michael Island, in western Alaska. The fossil pollen and spores in the sediment are studied to reconstruct the history of climate changes and ecosystem responses at high latitudes.