Climate Change

A sediment trap time series in the northern Gulf of Mexico 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...

Climate changes can significantly affect species and ecosystems. Historical and paleoenvironmental data record species and ecosystem responses to past climate changes, but these records become sparse as one goes further back in time. Model simulations can be used fill the spatial and temporal gaps in observed records to improve our understanding of the potential magnitude, rate, and spatial...

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...

Vegetation changes caused by climatic variations and/or land use may have large impacts on forests, agriculture, rangelands, natural ecosystems, and endangered species. Climate modeling studies indicate that vegetation cover, in turn, has a strong influence on regional climates, and this must be better understood before models can estimate future environmental conditions. To address these issues...

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...