Publications

New three-dimensional (3D) lithologic and stratigraphic models of the Santa Rosa Plain (California, USA) delineate the thickness, extent, and distribution of subsurface geologic units and allow integration of diverse data sets to produce a lithologic, stratigraphic, and structural architecture for the region. This framework can be used to predict pathways of groundwater flow beneath the...

Appropriate land‐use, watershed‐management, and flood‐attenuation plans are critical in the cross‐border urban environment known collectively as Ambos Nogales. This paper summarizes methodologies for predicting the watershed response associated with land‐use change within a spatial and temporal context through the use of a hydrological model in a cross‐border setting. The KINEROS2 model...

Pollen analysis of two cores with discontinuous records from a peat bog near Girdwood, in south-central Alaska, provides the basis for reconstructing the first radiocarbon-dated outline of postglacial history of vegetation in the upper Turnagain Arm area of Cook Inlet. Pollen data from clayey silt underlying peat at one site indicate that the earliest known vegetation in the Girdwood...

Activation chronologies of dune fields within the North American Great Plains are significant sources of paleoclimate information. Although many regional chronologies exist, several dune fields have been understudied, including the Casper Dune Field of central Wyoming. This study investigated aeolian dune sediment and buried soils of the Casper Dune Field. Complex parabolic and hairpin...

Geologic mapping in the northern Sierra Los Ajos reveals new stratigraphic and structural data relevant to deciphering the Mesozoic–Cenozoic tectonic evolution of the range. The northern Sierra Los Ajos is cored by Proterozoic, Cambrian, Devonian, Mississippian, and Pennsylvanian strata, equivalent respectively to the Pinal Schist, Bolsa Quartzite and Abrigo Limestone, Martin Formation...

The U.S. Geological Survey produced 1:24,000-scale post-earthquake image base maps incorporating high- and medium-resolution remotely sensed imagery following the 7.0 magnitude earthquake near the capital city of Port au Prince, Haiti, on January 12, 2010. Commercial 2.4-meter multispectral QuickBird imagery was acquired by DigitalGlobe on January 15, 2010, following the initial...

The U.S. Geological Survey produced 1:24,000-scale post-earthquake image base maps incorporating high- and medium-resolution remotely sensed imagery following the 7.0 magnitude earthquake near the capital city of Port au Prince, Haiti, on January 12, 2010. Commercial 2.4-meter multispectral QuickBird imagery was acquired by DigitalGlobe on January 15, 2010, following the initial...

Diatom assemblages in sediments from two subalpine lakes in the Uinta Mountains, Utah, show asynchronous changes that are related to both anthropogenic and natural inputs of dust. These lakes are downwind of sources of atmospheric inputs originating from mining, industrial, urban, agricultural and natural sources that are distributed within tens to hundreds of kilometers west and south...

As part of a study to derive records of past environmental change from lake sediments in the western United States, a set of cores was collected from Crevice Lake, Montana, in late February and early March 2001. Crevice Lake (latitude 45.000N, longitude 110.578W, elevation 1,713 meters) lies adjacent to the Yellowstone River at the north edge of Yellowstone National Park. The lake is...

No abstract available.

A snapshot of the thermal state of permafrost in northern North America during the International Polar Year (IPY) was developed using ground temperature data collected from 350 boreholes. More than half these were established during IPY to enhance the network in sparsely monitored regions. The measurement sites span a diverse range of ecoclimatic and geological conditions across the...

Paleoclimatic records show that the GreenlandIce Sheet consistently has lost mass in response to warming, and grown in response to cooling. Such changes have occurred even at times of slow or zero sea-level change, so changing sea level cannot have been the cause of at least some of the ice-sheet changes. In contrast, there are no documented major ice-sheet changes that occurred...