Climate Change

More than a third of the United States population lives in counties directly on the shoreline, making them vulnerable to hazards associated with changing sea level and storm surges associated with hurricanes and severe storms. The geologic record contains many examples of past intervals of warm climate and high sea level. "Geological Investigation of the Neogene" is examining proxy records of...

The Arctic is undergoing historically unprecedented changes in weather, sea ice, temperature and ecosystems. These changes have led to greater coastal erosion, greater export of freshwater, and changes to marine and terrestrial ecosystems, habitats, and productivity, among other trends. Meanwhile, many believe the Arctic “amplifies” large climate changes during both warm periods and ice ages and...

This research project will reconstruct Holocene climatic conditions to better understand human adaptation and response to past environmental variability.

A sediment trap time series in the northern Gulf of America is used to better assess the control of environmental variables (e.g., temperature and salinity) on the flux of both microfossils and molecular fossils to the sediments. The information gained from sediment trap studies is used to develop better proxy-based estimates of past oceanographic conditions from analyses of microfossils and...

This research uses state-of-the-art vegetation models to simulate vegetation changes across paleo (e.g., 127 ka; 127,000 years ago) to modern (e.g., 21st-century) time periods. We investigate the magnitude, rate, and drivers of vegetation change (e.g., wildfire, drought), with a focus on forest-to-grassland or shrubland and boreal forest-to-tundra transitions in North America. Results of this...

This project studies past high sea levels on coastlines that preserve fossil coral reefs or marine terraces. We ascertain the magnitudes of sea-level high stands by field mapping, stratigraphic measurements, and precise elevation measurements. Geochronology is accomplished by radiocarbon dating of mollusks (for Holocene-to-last-glacial deposits), uranium-series dating of corals (for high-sea...

The objectives of this project are to reconstruct detailed histories of Holocene hydroclimate and corresponding environmental change from geological archives such as lake sediment, peat, and wood to more fully understand past, ongoing, and future change and its impacts.

Springs and wetlands are among the most highly threatened ecosystems on Earth. Although geographically limited, they support more than 20% of all the threatened and endangered species in the United States. Scientists from the U.S. Geological Survey are examining the rock record to determine how springs and wetlands responded to abrupt climate change during prehistoric times and the recent geologic...

Large wildfires have raged across the western Americas in the past decade including the Las Conchas, New Mexico fire that burned 44,000 acres in a single day in 2011 (Orem and Pelletier, 2015, Geomorphology 232: 224-238, and references therein), the 2016 Fort McMurray, Alberta fire that required evacuating an entire city, and the 2015 Alaskan fire season that burned more than 5 million acres...

Understanding the rates and causes of land-use/land-cover (LULC) change helps answer questions about what, where, how, and why the Earth’s surface is changing. Land-surface change results from human activities or natural processes like floods, droughts, and wildfires, and many of these change processes are observable in satellite imagery. The growing historical catalog of satellite images allows...

Snow scientists with the USGS are unraveling specific weather, climate, and snowpack factors that contribute to large magnitude avalanches in an effort to understand these events as both a hazard and a landscape–level disturbance. The Snow and Avalanche Project (SNAP) advances our understanding of avalanche-climate interactions and wet snow avalanches, and improves public safety through innovative...