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Research about Colorado;Idaho;Utah;Wyoming

Source-linked reports with geographic coverage including Colorado;Idaho;Utah;Wyoming.

4 recordsLinked to original sources
USGS2011

Response of lake chemistry to atmospheric deposition and climate in selected Class I wilderness areas in the western United States, 1993-2009

The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service, Air Resource Management, conducted a study to evaluate long-term trends in lake-water chemistry for 64 high-elevation lakes in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming during 1993 to 2009. Understanding how and why lake chemistry is changing in mountain areas is essential for effectively managing and protecting high-elevation aquatic ecosystems. Trends in emissions, atmospheric deposition, and climate variables (air temperature and precipitation amount) were evaluated over a similar period of record. A main objective of the study was to determine if changes in atmospheric deposition of contaminants in the Rocky Mountain region have resulted in measurable changes in the chemistry of high-elevation lakes. A second objective was to investigate linkages between lake chemistry and air temperature and precipitation to improve understanding of the sensitivity of mountain lakes to climate variability.

Colorado;Idaho;Utah;Wyoming↗
USGS2011

Trends in lake chemistry in response to atmospheric deposition and climate in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming, 1993-2009

In 2010, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service, Air Resource Management, began a study to evaluate long-term trends in lake-water chemistry for 64 high-elevation lakes in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming during 1993 to 2009. The purpose of this report is to describe trends in the chemical composition of these high-elevation lakes. Trends in emissions, atmospheric deposition, and climate variables (air temperature and precipitation amount) are evaluated over a similar period of record to determine likely drivers of changing lake chemistry. Sulfate concentrations in precipitation decreased over the past two decades at high-elevation monitoring stations in the Rocky Mountain region. The trend in deposition chemistry is consistent with regional declines in sulfur dioxide emissions resulting from installation of emission controls at large stationary sources. Trends in nitrogen deposition were not as widespread as those for sulfate. About one-half of monitoring stations showed increases in ammonium concentrations, but few showed significant changes in nitrate concentrations. Trends in nitrogen deposition appear to be inconsistent with available emission inventories, which indicate modest declines in nitrogen emissions in the Rocky Mountain region since the mid-1990s. This discrepancy may reflect uncertainties in emission inventories or changes in atmospheric transformations of nitrogen species that may be affecting deposition processes. Analysis of long-term climate records indicates that average annual mean air temperature minimums have increased from 0.57 to 0.75 °C per decade in mountain areas of the region with warming trends being more pronounced in Colorado. Trends in annual precipitation were not evident over the period 1990 to 2006, although wetter than average years during 1995 to 1997 and drier years during 2001 to 2004 caused a notable decline in precipitation in the middle part of the record.

Colorado;Idaho;Utah;Wyoming↗
USGS1953

Reconnaissance during 1952 for uranium-bearing carbonaceous rocks in parts of Colorado, Utah, Idaho, and Wyoming

A reconnaissance for uranium-bearing carbonaceous rocks was made during the 1952 field season in 23 areas in Colorado, Utah, Idaho, and Wyoming. Uranium in small amounts occurs in several of the areas examined, but no deposits were found that might have commercial possibilities. As much as 0.03 percent uranium is in the ash of coal in the Caribou Mountain area in southwestern Idaho; 0.012 percent in the ash of coal in the Burnt Fork area of southwestern Wyoming; and 0.009 percent in the ash of coal from near Driggs in eastern Idaho. Seven additional areas were examined in which beds of coal or carbonaceous shale contained more than 0.002 but less than 0.007 percent uranium in the ash. Unweathered samples of bituminous sandstone from the Vernal area, Utah, contain minor quantities of uranium. ilities.

Colorado;Idaho;Utah;Wyoming↗