Publications
For more than a century, USGS scientists have conducted research in California’s Bay-Delta region. Informing natural-resource management decisions on the region’s issues, this research has been published in thousands of documents, some highlighted below.
Filter Total Items: 308
A Viscoelastic earthquake simulator with application to the San Francisco Bay region
Earthquake simulation on synthetic fault networks carries great potential for characterizing the statistical patterns of earthquake occurrence. I present an earthquake simulator based on elastic dislocation theory. It accounts for the effects of interseismic tectonic loading, static stress steps at the time of earthquakes, and postearthquake stress readjustment through viscoelastic relaxation of t
Authors
Fred F. Pollitz
Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentratio
Authors
N. K. Ganju, D. H. Schoellhamer
Managing water to protect fish: A review of California's environmental water account, 2001-2005
The Sacramento-San Joaquin Delta, the landward reach of the San Francisco Estuary, provides habitat for threatened delta smelt, endangered winter-run Chinook salmon, and other species of concern. It is also the location of huge freshwater diversion facilities that entrain large numbers of fish. Reducing the entrainment of listed fishes into these facilities has required curtailment of pumping, red
Authors
L. R. Brown, W. Kimmerer, R. Brown
Earthquake stress drops and inferred fault strength on the Hayward Fault, east San Francisco Bay, California
We study variations in earthquake stress drop with respect to depth, faulting regime, creeping versus locked fault behavior, and wall-rock geology. We use the P-wave displacement spectra from borehole seismic recordings of M 1.0-4.2 earthquakes in the east San Francisco Bay to estimate stress drop using a stack-and-invert empirical Green's function method. The median stress drop is 8.7 MPa, and mo
Authors
J.L. Hardebeck, A. Aron
Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay
Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wet
Authors
John Y. Takekawa, A.K. Miles, D. C. Tsao-Melcer, D. H. Schoellhamer, S. Fregien, N.D. Athearn
Data from theodolite measurements of creep rates on San Francisco Bay region faults, California
IntroductionOur purpose is to annually update our creep-data archive on San Francisco Bay region active faults for use by the scientific research community. Earlier data (1979-2001) were reported in Galehouse (2002) and were analyzed and described in detail in a summary report (Galehouse and Lienkaemper, 2003). A complete analysis of our earlier results obtained on the Hayward Fault was presented
Authors
Forrest S. McFarland, James J. Lienkaemper, S. John Caskey
How humans and nature have shaped the San Francisco Estuary since the Gold Rush
The San Francisco Estuary has undergone dramatic changes since the Gold Rush, as both natural forces and human activities have added and removed massive quantities of sediment, primarily sand and mud. A long-term perspective of sediment movement and patterns of sediment deposition and erosion is vital for effective management of wetlands, sediment contamination, dredging, mining, and other phenome
Authors
B. E. Jaffe
Benthic flux of nutrients and trace metals in the northern component of San Francisco Bay, California
Two sets of sampling trips were coordinated in late summer 2008 (weeks of July 8 and August 6) to sample the interstitial and overlying bottom waters at 10 shallow locations (9 sites
Authors
James S. Kuwabara, Brent R. Topping, Francis Parcheso, Anita C. Engelstad, Valerie E. Greene
Potential Inundation due to Rising Sea Levels in the San Francisco Bay Region
An increase in the rate of sea level rise is one of the primary impacts of projected global climate change. To assess potential inundation associated with a continued acceleration of sea level rise, the highest resolution elevation data available were assembled from various sources and mosaicked to cover the land surfaces of the San Francisco Bay region. Next, to quantify high water levels through
Authors
Noah Knowles
Integrating toxicity risk in bird eggs and chicks: Using chick down feathers to estimate mercury concentrations in eggs
The concentration of mercury (Hg) in eggs that causes reduced hatching success is regarded as a critical end point for Hg toxicity in birds. However, incorporating effects of in ovo mercury exposure on chick health and survival could improve risk assessment. We developed equations to predict Hg in eggs using Hg in chick down feathers, and vice versa, by assessing the relationship between Hg in fea
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith
Sexing California Clapper Rails using morphological measurements
California Clapper Rails (Rallus longirostris obsoletus) have monomorphic plumage, a trait that makes identification of sex difficult without extensive behavioral observation or genetic testing. Using 31 Clapper Rails (22 females, 9 males), caught in south San Francisco Bay, CA, and using easily measurable morphological characteristics, we developed a discriminant function to distinguish sex. We t
Authors
Cory T. Overton, Michael L. Casazza, John Y. Takekawa, Tobias M. Rohmer
Integrating terrestrial LiDAR and stereo photogrammetry to map the Tolay lakebed in northern San Francisco Bay
The Tolay Creek Watershed drains approximately 3,520 ha along the northern edge of San Francisco Bay. Surrounded by a mosaic of open space conservation easements and public wildlife areas, it is one of the only watersheds in this urbanized estuary that is protected from its headwaters to the bay. Tolay Lake is a seasonal, spring-fed lake found in the upper watershed that historically extended over
Authors
Isa Woo, Storesund, John Y. Takekawa, Rachel J. Gardiner, Ehret