Regions L2 Landing Page Tabs

Filter Total Items: 2,153
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Year Published: 2018

Estimating soil respiration in a subalpine landscape using point, terrain, climate and greenness data

Landscape carbon (C) flux estimates are necessary for assessing the ability of terrestrial ecosystems to buffer further increases in anthropogenic carbon dioxide (CO2) emissions. Advances in remote sensing have allowed for coarse-scale estimates of gross primary productivity (GPP) (e.g., MODIS 17), yet efforts to assess spatial patterns in...

Berryman, Erin Michele; Vanderhoof, Melanie K.; Bradford, John B.; Hawbaker, Todd J.; Henne, Paul D.; Burns, Sean P.; Frank, John M.; Birdsey, Richard A.; Ryan, Michael G.

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Year Published: 2018

Groundwater-storage change and land-surface elevation change in Tucson Basin and Avra Valley, south-central Arizona--2003-2016

The U.S. Geological Survey monitors groundwater-storage change and land-surface elevation change caused by groundwater withdrawal in Tucson Basin and Avra Valley—the two most populated alluvial basins within the Tucson Active Management Area. The Tucson Active Management Area is one of five active management areas in Arizona established by the...

Carruth, Robert L.; Kahler, Libby M.; Conway, Brian D.
Carruth, R.L., Kahler, L.M., and Conway, B.D., 2018, Groundwater-storage change and land-surface elevation change in Tucson Basin and Avra Valley, south-central Arizona—2003–2016: U.S. Geological Survey Scientific Investigations Report 2018–5154, 34 p.,

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Year Published: 2018

Examining forest structure with terrestrial lidar: Suggestions and novel techniques based on comparisons between scanners and forest treatments

Terrestrial laser scanners (TLSs) provide a tool to assess and monitor forest structure across forest landscapes. We present TLS methods, suggestions, and mapped guidelines for planning TLS acquisitions at varying scales and forest densities. We examined rates of point‐density decline with distance from two TLS that acquire data at relatively high...

Donager, Jonathon J.; Sankey, Temuulen T.; Sankey, Joel B.; Sanchez Meadorc, Andrew J.; Springer, Abraham E.; Bailey, John D.

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Year Published: 2018

Filtering of periodic infiltration in a layered vadose zone: 2. Applications and a freeware screening tool

We have developed a screening tool to visualize and conceptualize the filtering properties of a layered vadose zone. Climate projections indicate that rainfall timing and magnitude may change and impact groundwater resources. This increases the importance of understanding how the vadose zone filters infiltration variability and ultimately affects...

Dickinson, Jesse E.; Ferre, T.P.A

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Year Published: 2018

Agassiz’s desert tortoise (Gopherus agassizii) activity areas are little changed after wind turbine-induced fires in California

Wind turbine-induced fires at a wind energy facility in California, USA, provided an opportunity to study the before and after effects of fire on a population of protected Agassiz’s desert tortoises (Gopherus agassizii) in the Sonoran Desert, a species and ecosystem poorly adapted to fire. We compared annual activity areas (AAs) of tortoises in...

Lovich, Jeffrey E.; Agha, Mickey; Ennen, Joshua R.; Arundel, Terence R.; Austin, Meaghan

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Year Published: 2018

Image mosaic and topographic maps of Mercury

Map DescriptionsSheet 1: This image mosaic is based on observations acquired by the Mercury Dual Imaging System (MDIS; Hawkins and others, 2009), an instrument on the National Aeronautics and Space Agency (NASA) MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) spacecraft (Solomon and others, 2007). The Mercator projection...

Hunter, Marc A.; Hare, Trent M.; Hayward, Rosalyn K.; Chabot, Nancy L.; Hash, Christopher D.; Denevi, Brett W.; Ernst, Carolyn M.; Murchie, Scott L.; Blewett, David T.; Malaret, Erick R.; Solomon, Sean C.; Becker, Kris J.; Becker, Tammy L.; Weller, Lynn A.; Edmundson, Kenneth L.; Neuman, Gregory A.; Mazarico, Erwan; Perry, Mark E.
Hunter, M.A., Hare, T.M., Hayward, R.K., Chabot, N.L., Hash, C.D., Denevi, B.W., Ernst, C.M., Murchie, S.L., Blewett, D.T., Malaret, E.R., Solomon, S.C., Becker, K.J., Becker, T.L., Weller, L.A., Edmundson, K.L., Neuman, G.A., Mazarico, E., and Perry, M.E., 2018, Image mosaic and topographic maps of Mercury: U.S. Geological Survey Scientific Investigations Map 3404, scale 1:20,000,000 and 1:12,157,366,

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Year Published: 2018

Using research networks to create the comprehensive datasets needed to assess nutrient availability as a key determinant of terrestrial carbon cycling

A wide range of research shows that nutrient availability strongly influences terrestrial carbon (C) cycling and shapes ecosystem responses to environmental changes and hence terrestrial feedbacks to climate. Nonetheless, our understanding of nutrient controls remains far from complete and poorly quantified, at least partly due to a lack of...

Vicca, Sara; Stocker, Benjamin; Reed, Sasha C.; Wieder, William R.; Bahn, Michael; Fay, Philip A.; Janssens, Ivan; Lambers, Hans; Penuelas, Josep; Piao, Shilong; Rebel, Karin; Sardans, Jordi; Sigurdsson, Bjarni D.; Van Sundert, Kevin; Wang, Ying-Ping; Zaehle, Sonke; Ciais, Philippe

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Year Published: 2018

Adapting management to a changing world: Warm temperatures, dry soil, and interannual variability limit restoration success of a dominant woody shrub in temperate drylands

Restoration and rehabilitation of native vegetation in dryland ecosystems, which encompass over 40% of terrestrial ecosystems, is a common challenge that continues to grow as wildfire and biological invasions transform dryland plant communities. The difficulty in part stems from low and variable precipitation, combined with limited understanding...

Shriver, Robert K.; Andrews, Caitlin M.; Pilliod, David S.; Arkle, Robert; Welty, Justin; Germino, Matthew J.; Duniway, Michael C.; Pyke, David A.; Bradford, John B.
Shriver, R.K., Andrews, C.M., Pilliod, D.S., Arkle, R.S., Welty, J.L., Germino, M.J., Duniway, M.C., Pyke, D.A., and Bradford, J.B., 2018, Adapting management to a changing world--Warm temperatures, dry soil, and interannual variability limit restoration success of a dominant woody shrub in temperate drylands: Global Change Biology, online,

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Year Published: 2018

Probabilistic substrate classification with multispectral acoustic backscatter: A comparison of discriminative and generative models

We propose a probabilistic graphical model for discriminative substrate characterization, to support geological and biological habitat mapping in aquatic environments. The model, called a fully-connected conditional random field (CRF), is demonstrated using multispectral and monospectral acoustic backscatter from heterogeneous seafloors in...

Buscombe, Daniel; Grams, Paul E.

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Year Published: 2018

Mars global digital dune database (MGD3)—Composition, stability, and thermal inertia

The Mars Global Digital Dune Database (MGD3) is an online repository that has catalogued dune fields larger than 1 km2 located between latitudes 90° N. and 90° S. The work presented here expands upon previous MGD3 open-file reports, with a new emphasis upon characterizing dune fields through composition, stability, and thermal inertia. Included in...

Gullikson, Amber L.; Hayward, Rosalyn K.; Titus, Timothy N.; Charles, Heather; Fenton, Lori K.; Hoover, Rachael H.; Putzig, Nathaniel E.
Gullikson, A.L., Hayward, R.K., Titus, T.N., Charles, H., Fenton, L.K., Hoover, R., and Putzig, N.E., 2018, Mars global digital dune database (MGD3)—Composition, stability, and thermal inertia: U.S. Geological Survey Open-File Report 2018–1164, 17 p.,

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Year Published: 2018

Findings and lessons learned from the assessment of the Mexico-United States transboundary San Pedro and Santa Cruz aquifers: The utility of social science in applied hydrologic research

Study RegionThis study region encompasses the Transboundary San Pedro and Santa Cruz aquifers which are shared between the states of Sonora (Mexico) and Arizona (US). Special regional considerations include a semi-arid climate, basin-fill aquifers with predominantly montane recharge areas, economic drivers in the mining, trade, and military...

Callegary, James B.; Megdal, Sharon B.; Tapia Villaseñor, Elia María; Petersen-Perlman, Jacob D.; Minjárez Sosa, Ismael; Monreal, R.; Gray, F.; Grijalva Noriega, Francisco

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Year Published: 2018

Distribution, habitat, and population size of Island Night Lizards on San Nicolas Island, California

The Island Night Lizard (Xantusia riversiana) was removed from the federal list of threatened species in May 2014. This strongly differentiated species is endemic to 3 of the southern California Channel Islands—San Clemente, San Nicolas, and Santa Barbara. Suitable habitat for Island Night Lizards is extensive on San Clemente Island, and the...

Drost, Charles A.; Fellers, Gary M.; Murphey, Thomas R.; Kleeman, Patrick M.; Halstead, Brian J.; O'Donnell, Ryan P.
Drost, C.A., Fellers, G.M., Kleeman, P.M., Halstead, B.J., and O’Donnell, R.P., 2018, Distribution, habitat, and population size of island night lizards on San Nicolas Island, California: Western North American Naturalist, v. 78, no. 3, article 7, p. 358-369,

Filter Total Items: 239
May 31, 2017

New USGS Maps of Mars Reveal Ancient Oases

Flyover of the southeast Ceti Mensa map. Distinct groups of rock layers, called geologic units, are shaded in different colors, with dark browns representing the oldest rocks and green representing the youngest rocks. All of these rocks formed as wind-blown sand that became trapped in shallow, ephemeral lakes, similar to the wet playas of the desert southwest US. The

May 25, 2017

PubTalk 5/2017 — Underwater secrets of the Hayward fault zone

Title: Underwater Secrets of the Hayward Fault Zone: Integrated 3D imaging to understand earthquake hazards 

  • Underwater imaging provides a unique opportunity to study urban fault hazards.
  • How do we link surface structures to depths where earthquakes occur?
  • How does "acoustic trenching" help us understand earthquake history?
Two adjacent poles holding video cameras near top, one control box near bottom, one man holding small tool near control box.
May 12, 2017

Beach-monitoring video cameras atop hotel in Santa Cruz, California

USGS ocean engineer Gerry Hatcher (left) and USGS postdoctoral oceanographer Shawn Harrison make adjustments to a computer controlling two video cameras on the roof of the Dream Inn, a 10-story hotel overlooking Monterey Bay in Santa Cruz, California. One camera looks eastward over Santa Cruz Main Beach and boardwalk, and the other southward over Cowells Beach. Since May

Distant view of the shore from a flat rooftop that is visible at bottom of image.
May 6, 2017

“Snapshot” or first frame of beach video, Santa Cruz, California

Snapshot, or first frame of from a 10-minute video taken May 6, 2017, in Santa Cruz, California. View is from atop a hotel looking down on Cowells Beach, a popular surf spot. Researchers at the USGS are using these and other video images to improve understanding and computer modeling of beach processes, especially those that change the coast. 

Distant view of the shore from a flat rooftop that is visible at bottom of image.
May 6, 2017

Time-averaged image from video of beach in Santa Cruz, California

Time-averaged image, or “timex,” created by averaging the intensity of light recorded at each spot, or “pixel,” during a 10-minute video taken at Santa Cruz, California, on May 6, 2017. Blurred white zones show where waves are breaking. Line between wet and dry sand shows the maximum height on the beach reached by the waves (“runup”). Researchers at the USGS are using

Image in mostly black and white tones, showing distant view of beach stretching from bottom left to upper right.
May 6, 2017

Variance image from video of beach in Santa Cruz, California

“Variance” image produced from video shot at Cowells Beach in Santa Cruz, California, on May 6, 2017. The more the light intensity changes at a given spot, or “pixel,” during the video, the brighter the value assigned to that pixel. Motion tends to produce changes in light intensity. Note bright areas along and beyond the shore where waves were breaking. Researchers are

An extremely rare Mojave River western pond turtle was recently observed in the Mojave Desert.
May 4, 2017

An extremely rare Mojave River western pond turtle

An extremely rare Mojave River western pond turtle was recently observed by USGS scientists and staff from The Living Desert Zoo and Gardens in the Mojave Desert. Turtles of this population have rarely been seen since the late 1990s.

A cabin along Alaska's Arctic coast was recently washed into the ocean because the bluff it was sitting on eroded away.
May 3, 2017

Climate Change Impacts

From the Sound Waves Newletter article, "Erosion Doubles Along Part of Alaska's Arctic Coast — Cultural and Historical Sites Lost" at

March 31, 2017

Establishing Forster's Tern Nesting Colonies

Scientists from the USGS Western Ecological Research Center (WERC) are conducting a "social attraction" study for seabirds in the Don Edwards San Francisco Bay National Wildlife Refuge. Historically, this region offered wetland habitats to local wildlife. With the introduction of industrial salt ponds and human development, however, much of this habitat was lost. Now,

row of palm trees along a low cliff behind a narrow beach with very little sand
February 28, 2017

Beach loss and armoring at Goleta Beach

Beach loss and armoring at Goleta Beach, very low (negative) tide

long stretch of beach, with row of houses teetering on the edge of the cliff above beach. Bare rocks exposed & no sand on beach
February 28, 2017

Exposed bedrock at Isla Vista beach

Bedrock exposed at low tide along the beach at Isla Vista, California

house perched at the top of cliff edge above beach.
February 28, 2017

Exposed bedrock at Isla Vista

Exposed bedrock on the beach during very low (negative) tide at Isla Vista, California

Research and technical support provided by USGS makes a difference Some recent press releases and media advisories from the Pacific Region are highlighted below.

Filter Total Items: 72
Sandy ocean beach with low cliffs on the right side. Ocean visible at left side. One person walking on beach
February 14, 2017

In a study released today, U.S. Geological Survey scientists and their colleagues document how the 2015-16 winter featured one of the most powerful El Niño climate events of the last 145 years.

K2 Seismic Station
February 2, 2017

The U. S. Geological Survey is seeking volunteers to host temporary seismic stations in the Walnut Creek/Pleasant Hill/Concord California area. Volunteers will be assisting with a new ground motion study that will begin in March 2017.

Clark's Grebe at Thermalito Afterbay, CA
January 24, 2017

A new study published in PLOS ONE demonstrates that current conservation planning efforts for waterbird habitat in the Central Valley can likely compensate for habitat loss through the middle of the century.

Photo of Pigeon Canyon just before it merges with Snake Gulch in northern Arizona. 
January 24, 2017

Uranium levels in Pigeon Spring, just north of the Grand Canyon, are likely due to a natural source of uranium and not related to the nearby former Pigeon Mine, according to a recent study by the U.S. Geological Survey.

head shot of man
January 19, 2017

The U.S. Geological Survey is pleased to announce the selection of Dr. Guy Gelfenbaum as the new director of their Pacific Coastal and Marine Science Center in Santa Cruz, California Gelfenbaum succeeds Dr. Robert Rosenbauer who held the position for the past six years. Rosenbauer is retiring to a Scientist Emeritus position.

Man in orange safety suit and helmet, and thumb up,  standing while riding a personal watercraft
January 12, 2017

On January 13, scientists from the U.S. Geological Survey will be working on the beach in Santa Cruz at the mouth of the San Lorenzo River. Using a sonar-equipped boat and personal watercraft, they will be surveying the beach and the nearby ocean bottom to compile a three-dimensional map of how the beach changed during storms that struck this week.

USGS: Science for a changing world
January 10, 2017

The U.S. Geological Survey’s California Water Science Center is hosting a media event Wednesday, Jan. 11 at a USGS streamgage location about 7 miles north of Santa Cruz, California. A hydrologist will be available for interviews as field crews collect streamflow data.


Image: USGS Logo
January 8, 2017

The U.S. Geological Survey’s California Water Science Center is hosting a media event Monday, Jan. 9 at a USGS streamgage location below Friant Dam, a streamflow site with significance to the San Juan River Restoration Project.

Photo of scientists conducting water chemistry tests for the San Pedro River aquifer. 
December 20, 2016

For the first time, information about the San Pedro River Aquifer is now available from both the U.S. and Mexico in a new, collaborative report issued from the International Boundary and Water Commission, the Mexican National Water Commission, the U.S. Geological Survey and the Universities of Arizona and Sonora.

still waters reflecting image of grasses growing next to it, with bright blue sky.
November 15, 2016

Successfully resolving California’s long-standing water supply and ecosystem restoration conflicts in the Delta requires developing sound policy solutions based on data derived from the best available science.

Nine USGS Science Centers are administered by the Pacific Regional office, which is headquartered in Sacramento, California.

The Pacific Region works with a wide array of partners across the country, including other Federal and state agencies, regional and local governments, academic institutions, research organizations, non-governmental organizations, and more.

Filter Total Items: 66