Holocene Hydroclimate of Western North America

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The semiarid western United States faces increasing water demands, focusing interest on hydroclimate, the past, present and future trends in climate with respect to water. To better understand past, ongoing, and future hydroclimate, this project develops proxy-based records from geologic strata by assessing the chemical signatures that are contained within 10,000 years of lake sediments.  The resulting records provide a better understanding of the full range of climate states that occurred during the Holocene, the most recent period in Earth’s history with similar global boundary conditions to the pre-industrial period (similar ice-sheet extent, sea-level, and atmospheric CO2 concentrations).  The motivation is to provide a comparable long-term context of hydroclimatic variations and extremes to better evaluate those observed during the past ~50 to 100 years.  To these ends, there is a present day component to the research where a proxy response to ongoing water and climate changes is evaluated.  Lake waters are sampled and ongoing changes are documented for the recent past using remotely sensed data, including optical imagery (aerial and satellite), lidar, elevation measurements and Global Positioning System (GPS).

Lidar shows the fine scale (<2m) topographic relief surrounding an Alaskan lake that has diminished in size since the early 1980s.  The blue shaded areas indicate the lake shoreline and depths measured by GPS in 2008 whereas the outermost blue line indicates the lake shorelines mapped by the USGS in 1978 from aerial photography.  The red line is the 1978 shoreline derived from lidar.

Lidar shows the fine scale (2m) topographic relief surrounding an Alaskan lake that has diminished in size since the early 1980s.  The blue shaded areas indicate the lake shoreline and depths measured by GPS in 2008, whereas the outermost blue line indicates the lake shorelines mapped by the USGS in 1978 from aerial photography.  The red line is the 1978 shoreline derived from lidar.

http://www.usgs.gov/climate_landuse/clu_rd/projects/hhydroclimate.asp

Author Name
Lesleigh Anderson
Author Email
land@usgs.gov