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Southwest Region

The Southwest Region covers Arizona, California, Nevada, and a portion of southern Oregon. Our scientists do a broad array of research and technical assistance throughout the U.S. and across the globe. The Regional Office, headquartered in Sacramento, provides Center oversight & support, facilitates internal & external collaborations, and works to further USGS strategic science direction.

News

Revisiting the 1957 Aleutian Earthquake: New Insights into Tsunami Hazards for Hawaiʻi

Revisiting the 1957 Aleutian Earthquake: New Insights into Tsunami Hazards for Hawaiʻi

Art Illuminates the Grand Canyon: Exploring the Environmental Puzzle

Art Illuminates the Grand Canyon: Exploring the Environmental Puzzle

New tool informs flooding and sea level rise solutions for San Francisco Bay Area

New tool informs flooding and sea level rise solutions for San Francisco Bay Area

Publications

Bees of the Buenos Aires National Wildlife Refuge—A preliminary report on a bee survey in a vulnerable semi-desert grassland of the Sonoran Desert

Pollinators are vital to the continued existence and seed production of about 87.5 percent of all flowering plants (Ollerton and others, 2011). In the semi-desert grasslands of Buenos Aires National Wildlife Refuge, in the Sonoran Desert of the United States, flowering forbs provide seed vital to the food base of wildlife, including the 136 species of resident and migratory birds using the Refuge’
Authors
Kathryn A. Thomas, Angela M. Hoover, M. Kathryn Busby

Analyzing spatial distributions and alignments of pitted cone features in Utopia Planitia on Mars

Martian geomorphology and surface features provide links to understanding past geologic processes such as fluid movement, local and regional tectonics, and feature formation mechanisms. Pitted cones are common features in the northern plains basins of Mars. They have been proposed to have formed from upwelling volatile-rich fluids, such as magma or water-sediment slurries. In this study, we map th
Authors
Mackenzie M. Mills, Alfred S. McEwen, Amanda N. Hughes, Ji-Eun Kim, Chris Okubo

Soil surface treatments and precipitation timing determine seedling development across southwestern US restoration sites

Restoration in dryland ecosystems often has poor success due to low and variable water availability, degraded soil conditions, and slow plant community recovery rates. Restoration treatments can mitigate these constraints but, because treatments and subsequent monitoring are typically limited in space and time, our understanding of their applicability across broader environmental gradients remains
Authors
Hannah Lucia Farrell, Seth M. Munson, Bradley J. Butterfield, Michael C. Duniway, Aksasha M Faist, Elise S Gornish, Caroline Havrilla, Loralee Larios, Sasha C. Reed, Helen I Rowe, Katherine M. Laushman, Molly L. McCormick

Science

Can ruderal components of biocrust (mosses and cyanobacteria) be maintained under increasing threats of drought, grazing and feral horses?

Biological soil crusts (biocrusts) are a community of living organisms, like moss, lichen, and algae, covering soils in arid and semi-arid ecosystems, providing important ecological functions like carbon cycling and soil stabilization. Analyses show that biocrusts are negatively associated with the abundance of invasive annual grasses that are responsible for increasing fire across the Great Basin...
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Can ruderal components of biocrust (mosses and cyanobacteria) be maintained under increasing threats of drought, grazing and feral horses?

Biological soil crusts (biocrusts) are a community of living organisms, like moss, lichen, and algae, covering soils in arid and semi-arid ecosystems, providing important ecological functions like carbon cycling and soil stabilization. Analyses show that biocrusts are negatively associated with the abundance of invasive annual grasses that are responsible for increasing fire across the Great Basin...
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U.S. Geological Survey Develops Per- and Polyfluoroalkyl Substances (PFAS) Sampling Guide

USGS scientist’s published a Per- and Polyfluoroalkyl Substances (PFAS) sampling guide for personnel involved with Natural Resource Damage Assessment and Restoration (NRDAR) activities. This guide introduces individuals involved in NRDAR efforts and other investigators to key concepts and considerations when sampling different environmental media for PFAS.
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U.S. Geological Survey Develops Per- and Polyfluoroalkyl Substances (PFAS) Sampling Guide

USGS scientist’s published a Per- and Polyfluoroalkyl Substances (PFAS) sampling guide for personnel involved with Natural Resource Damage Assessment and Restoration (NRDAR) activities. This guide introduces individuals involved in NRDAR efforts and other investigators to key concepts and considerations when sampling different environmental media for PFAS.
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Anthropogenic Nutrient Loading and Coral Health at Ofu, American Samoa

Declining water quality poses a significant and persistent threat to coral reefs worldwide, contributing to their widespread degradation. Identifying the specific impacts of water quality stressors is challenging due to the complex interplay of various physical and biological factors affecting reef health. Submarine groundwater discharge (SGD) plays a crucial role in transporting nutrients into...
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Anthropogenic Nutrient Loading and Coral Health at Ofu, American Samoa

Declining water quality poses a significant and persistent threat to coral reefs worldwide, contributing to their widespread degradation. Identifying the specific impacts of water quality stressors is challenging due to the complex interplay of various physical and biological factors affecting reef health. Submarine groundwater discharge (SGD) plays a crucial role in transporting nutrients into...
Learn More