Paleoclimate
Paleoclimate
Paleoclimate studies provide an essential perspective for assessing the potential impacts of future climate on natural systems and the people who rely on them. GECSC scientists interpret geologic evidence of past climate changes over broad temporal and spatial scales and provide the information needed to understand the rates and patterns of Earth system response to a range of climate and landscape changes. Integration of these data with climate modeling efforts provides a means to improve understanding of the impacts of change and feedbacks between the Earth and climate systems, as well as improve model performance and prediction capabilities.
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USGS North American Packrat Midden Database
A Database of Paleoecological Records from Neotoma Middens in Western North America Dry caves and rockshelters in western North America host a unique and valuable paleobotanical resource known as packrat middens. Packrat ( Neotoma spp.) middens composed of desiccated fecal matter and urine also contain well preserved fossil plant materials. Over fifty years of scientific investigations on packrat...
Did we start the fire? Climate, Fire and Humans
The past decade encompasses some of the most extensive fire activity in recorded history. An area the size of Vermont (~24,000 km2) burned in a single Siberian fire in the summer of 2019 (Kehrwald et al., 2020 and references therein) while Australia, Indonesia and the Amazon have all experienced their most intense fires in recorded history (van Wees et al, 2021 and references therein). As more...
Understanding long-term drivers of vegetation change and stability in the Southern Rocky Mountains with paleoecological data and ecological models
Drought and fire are powerful disturbance agents that can trigger rapid and lasting changes in the forests of western North America. Over the last decade, increases in fire size and severity coincided with warming, drought, and earlier snowmelt, factors that projected climatic changes are likely to exacerbate. However, recent observations are brief relative to the lifespans of trees and include...
Quaternary Hydroclimate Records of Spring Ecosystems
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited...
Denali National Park Geohazards Geologic Mapping
Denali National Park (DENA) is a major draw for tourism and recreation and a major economic engine for central Alaska. However, the geologic forces that created the steep landscape of DENA also make it prone to geologic hazards (geohazards) like landslides, debris flows, and earthquakes. DENA has only one major road, called the ‘Park Road’, that serves nearly all of its infrastructure. Since 2017...
Past Perspectives of Water in the West
In the intermountain west, seasonal precipitation extremes, combined with population growth, are creating new challenges for the management of water resources, ecosystems, and geologic hazards. This research contributes a comprehensive long-term context for a deeper understanding of past hydrologic variability, including the magnitude and frequency of drought and flood extremes and ecosystem...
Geologic Records of High Sea Levels
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...
Holocene Hydroclimate of Western North America
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.
Paleohydrology of Desert Wetlands
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...
Sources, compositions, and effects of atmospheric dust from American Drylands
The Drylands Project undertakes studies to measure past and ongoing changes in dust sources, flux, and composition in the American West, and strives to understand the effects of atmospheric dust on pressing national and global issues of snowmelt acceleration, air quality, and human health. The project develops the capability to forecast future dust emission/deposition and effects on the basis of...
Terrestrial Records of Holocene Climate Change: Fire, climate and humans
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...