Publications

Data from Jupiter's moon Io returned by the Galileo spacecraft have been used to create a geologic map of Prometheus Patera, its associated flow field, and nearby features. We have identified the location of the vent that fed the Prometheus flow field during the Galileo epoch in the north-eastern portion of the main Prometheus flow field. This vent is the probable source of a small sulphur-rich pl

This report summarizes the results of the first comprehensive inventory of vascular plants and vertebrates at Chiricahua National Monument (NM) in Arizona. This project was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in the Sonoran Desert Network of parks in Arizona and New Mexico. In 2002, 2003, and 2004 we surveyed for plants and vert

To learn how migrating birds determine where to stop and find food, scientists from the U.S. Geological Survey, Northern Arizona University, and The University of Arizona studied the behavior of 28 species of neotropical migrant songbirds - warblers, flycatchers, tanagers, and vireos - along the lower Colorado River from 2001 to 2004. They found that, like interstate travelers greeted by restauran

Weather data constitute an integral part of ecosystem monitoring in the Colorado River corridor and are particularly valuable for understanding processes of landscape change that contribute to the stability of archeological sites. Data collected in 2007 are reported from nine weather stations in the Colorado River corridor through Grand Canyon, Ariz. The stations were deployed in February and Marc

The protection of resources found in Glen Canyon National Recreation Area and Grand Canyon National Park, Arizona, emerged as a significant public concern in the decades following the completion of Glen Canyon Dam in 1963. The dam, which lies about 15 miles upstream from the park, altered the Colorado River's flow, temperature, and sediment-carrying capacity, resulting over time in beach erosion,

Mark-recapture methods have been used for the past two decades to assess trends in adult abundance and recruitment of the Little Colorado River (LCR) population of humpback chub. These methods indicate that the adult population declined through the 1980s and early 1990s but has been increasing for the past decade. Recruitment appears also to have increased, particularly in the 2003-4 period. Consi

The Colorado River Basin supports one of the most distinctive fish communities in North America, including the federally endangered humpback chub (Gila cypha). One of only six remaining populations of this fish is found in Grand Canyon, Arizona. U.S. Geological Survey scientists and their cooperators are responsible for monitoring the Grand Canyon population. Analysis of recently collected data in

The Grand Canyon of the Colorado River, one of the world's most spectacular gorges, is a premier U.S. National Park and a World Heritage Site. The canyon supports a diverse array of distinctive plants and animals and contains cultural resources significant to the region's Native Americans. About 15 miles upstream of Grand Canyon National Park sits Glen Canyon Dam, completed in 1963, which crea

Caves in northern Arizona and western New Mexico are being researched and inventoried by scientists with the U.S. Geological Survey and cooperating agencies. Southwestern caves have been little studied, and scientists are now finding that these lightless and nutrient-poor natural systems are home to life forms found nowhere else on Earth. This research has identified unique communities of arthropo

We estimated size-specific capture probabilities of age-0 rainbow trout Oncorhynchus mykiss in the Lee's Ferry Reach of the Colorado River, Arizona, by backpack and boat electrofishing at discrete shoreline sites using both depletion and mark-recapture experiments. Our objectives were to evaluate the feasibility of estimating capture probability for juvenile fish in larger rivers; to determine how

Large sediment fluxes can have significant impacts on ecosystems. We measured incoming and outgoing sediment across a gradient of soil disturbance (livestock grazing, plowing) and annual plant invasion for 9 years. Our sites included two currently ungrazed sites: one never grazed by livestock and dominated by perennial grasses/well-developed biocrusts and one not grazed since 1974 and dominated by

No abstract available.