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Estimates of suspended sediment entering San Francisco Bay from the Sacramento and San Joaquin Delta, San Francisco Bay, California
This study demonstrates the use of suspended-sediment concentration (SSC) data collected at Mallard Island as a means of determining suspended-sediment load entering San Francisco Bay from the Sacramento and San Joaquin River watersheds. Optical backscatter (OBS) data were collected every 15 min during water years (WYs) 1995-2003 and converted to...McKee, L.J.; Ganju, N.K.; Schoellhamer, D.H.
Fifty-two years of pineapple-express storms across the West Coast of North America
No abstract available.Dettinger, M.D.
Flooding on California's Russian River: Role of atmospheric rivers
Experimental observations collected during meteorological field studies conducted by the National Oceanic and Atmospheric Administration near the Russian River of coastal northern California are combined with SSM/I satellite observations offshore to examine the role of landfalling atmospheric rivers in the creation of flooding. While recent...Ralph, F.M.; Neiman, P.J.; Wick, G.A.; Gutman, S.I.; Dettinger, M.D.; Cayan, D.R.; White, A.B.
Flow convergence caused by a salinity minimum in a tidal channel
Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of...Warner, John C.; Schoellhamer, David H.; Burau, Jon R.; Schladow, S. Geoffrey
Intradaily variability of water quality in a shallow tidal lagoon: Mechanisms and implications
Although surface water quality and its underlying processes vary over time scales ranging from seconds to decades, they have historically been studied at the lower (weekly to interannual) frequencies. The aim of this study was to investigate intradaily variability of three water quality parameters in a small freshwater tidal lagoon (Mildred Island...Lucas, L.V.; Sereno, D.M.; Burau, J.R.; Schraga, T.S.; Lopez, C.B.; Stacey, M.T.; Parchevsky, K.V.; Parchevsky, V.P.
Mountain hydrology of the western United States
Climate change and climate variability, population growth, and land use change drive the need for new hydrologic knowledge and understanding. In the mountainous West and other similar areas worldwide, three pressing hydrologic needs stand out: first, to better understand the processes controlling the partitioning of energy and water fluxes within...Bales, Roger C.; Molotch, Noah P.; Painter, Thomas H; Dettinger, Michael D.; Rice, Robert; Dozier, Jeff
Trends in snowfall versus rainfall in the western United States
The water resources of the western United States depend heavily on snowpack to store part of the wintertime precipitation into the drier summer months. A well-documented shift toward earlier runoff in recent decades has been attributed to 1) more precipitation falling as rain instead of snow and 2) earlier snowmelt. The present study addresses the...Knowles, N.; Dettinger, M.D.; Cayan, D.R.
Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary
Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans...Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.
Warming and earlier spring increase Western U.S. forest wildfire activity
Western United States forest wildfire activity is widely thought to have increased in recent decades, yet neither the extent of recent changes nor the degree to which climate may be driving regional changes in wildfire has been systematically documented. Much of the public and scientific discussion of changes in western United States wildfire has...Westerling, A.L.; Hidalgo, H.G.; Cayan, D.R.; Swetnam, T.W.
What is causing the phytoplankton increase in San Francisco Bay?
The largest living component of San Francisco Bay is the phytoplankton, a suspension of microscopic cells that convert sunlight energy into new living biomass through the same process of photosynthesis used by land plants. This primary production is the ultimate source of food for clams, zooplankton, crabs, sardines, halibut, sturgeon, diving...Cloern, J.E.; Jassby, A.D.; Schraga, T.S.; Dallas, K.L.
Sedimentation and bathymetry changes in south San Francisco Bay: 1858-1983Foxgrover, A.C.; Higgins, S.A.; Ingraca, M.K.; Jaffe, B.E.; Smith, R.E.
Analysis of pesticides in surface water and sediment from Yolo Bypass, California, 2004-2005
Inputs to the Yolo Bypass are potential sources of pesticides that could impact critical life stages of native fish. To assess the direct inputs during inundation, pesticide concentrations were analyzed in water, in suspended and bed-sediment samples collected from six source watersheds to the Yolo Bypass, and from three sites within the Bypass in...Smalling, Kelly L.; Orlando, James L.; Kuivila, Kathryn
USGS scientist Daniel Hoover mapping the beach at Santa Cruz with a GPS-equipped backpack unit.
Residents and visitors both revel in Kauai’s lush landscape, and beneath its seascape. However, it’s underwater where things don’t look so healthy. Scientists from the U.S. Geological Survey put together a detailed picture of the physical environment of the coral reefs at Makua Beach. Understanding just what these reefs are exposed to and for how long, may help explain why...
What does it take to become an ocean engineer? Here is the path that USGS Gerry Hatcher took.
A presentation on "Unusual Sources of Tsunamis From Krakatoa to Monterey Bay" by Eric Geist, USGS Research Geophysicist
- Not all tsunamis are generated by earthquakes.
- Tsunamis can be caused by volcanoes, landslides, and even atmospheric disturbances
- Data from tide gauges can help unravel the complex physics of these sources
An atmospheric river, or narrow band of moisture moving from the tropics to the higher latitudes, hit California in early January and brought the first heavy rains of 2017. While these storms help a drought-stricken state, the onslaught of rain triggers floods and mudslides, and fills rising rivers with sediment and debris. Here the San Lorenzo River flows full and muddy...
Mount Crillon in the backdrop during a multibeam bathymetry survey of the Queen Charlotte-Fairweather Fault, offshore southeastern Alaska.
The Department of the Interior Pacific Islands Climate Science Center and the University of Hawaiʻi at Hilo developed and hosted a Climate Change Boot Camp that showcased collaborative research efforts within UH Hilo’s Tropical Conservation Biology and Environmental Science graduate program that are driven by local natural resource managers across Hawaiʻi Island. The event...
USGS research geologist Jon Warrick explains how his team applied structure-from-motion analysis to photos from the California Coastal Records Project to measure coastal change. Jon Warrick explains a “difference map” constructed from structure-in-motion data. Red areas indicate loss of material (erosion); blue areas show addition of material (deposition).
Ecological Stressors: It's a Lot of 'WERC'
"There's is no place like California" by A. Keith Miles, Center Director, USGS Western Ecological Research Center
Highlights of the science of the USGS Western Ecological Research Center:
- Wildlife, drought, sea level rise
- Endangered species, species of concern
- Alternate energy,
Research and technical support provided by USGS makes a difference Some recent press releases and media advisories from the Pacific Region are highlighted below.
SANTA CRUZ, California — The southern sea otter, Enhydra lutris nereis, continues its climb toward recovery, according to the annual count released today by the U.S. Geological Survey and partners.
Tsunami evacuation planning in coastal communities is typically based on maximum evacuation zones that reflect a combination of all potential extreme tsunamis. However, in the case of a smaller tsunami, this approach may result in more people being evacuated than need to be, and in doing so, may overly disrupt the local economy, and strain resources needed during emergency response.
A team of USGS scientists spent 10 days in the wilderness, exploring one of the fastest-moving faults in America
MEDIA ADVISORY: Faculty and students from California State University, East Bay, U.S. Geological Survey scientists, and community volunteers are conducting an experiment to visualize the subsurface in and around the Hayward Fault and measure how the ground in different neighborhoods responds to earthquake shaking.
Kauai Island forest birds at tipping point toward extinction
Media Advisory: Photo Opportunity
If past patterns of California land-use change continue, projected water needs by the year 2062 will increase beyond current supply.
Elevated levels of trace metals such as iron, lead, nickel and zinc were found in streams of the San Gabriel Mountains north of Los Angeles, California, at water-quality levels higher than the Environmental Protection Agency’s Aquatic Life Ambient Water Quality Criteria, according to a new U.S. Geological Survey study.
A magnitude 7.0 earthquake struck Japan on April 16, 2016 at 1:25 a.m. local time (April 15, 16:25 UTC).
Methane emissions from restored wetlands may offset the benefits of carbon sequestration a new study from the U.S. Geological Survey suggests.
For the first time, scientists at the U.S. Geological Survey have mapped the active surface trace of the Rodgers Creek Fault through the central part of the northern California city of Santa Rosa. Urban development has, until now, obscured its exact location.
El Niño is a phenomenon that occurs when unusually warm ocean water piles up along the equatorial west coast of South America. When this phenomenon develops, it affects weather patterns around the globe, including the winter weather along the west coast of North America. This unusual pattern of sea surface temperatures occurs in irregular cycles about three to seven years apart.
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.