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Filter Total Items: 612
Year Published: 1999

Remote sensing: visual cues to suspended-solids transport in San Francisco Bay, California

No abstract available.

Ruhl, C.A.; Schoellhamer, D.H.; Stumpf, R.P.; Lindsay, C.L.
Attribution: Pacific

Year Published: 1999

Sedimentary record of anthropogenic and biogenic polycyclic aromatic hydrocarbons in San Francisco Bay, California

Dated sediment cores collected from Richardson and San Pablo Bays in San Francisco Bay were used to reconstruct a history of polycyclic aromatic hydrocarbon (PAH) contamination. The sedimentary record of PAHs in Richardson Bay shows that anthropogenic inputs have increased since the turn of the century, presumably as a result of increasing...

Pereira, W.E.; Hostettler, F.D.; Luoma, S.N.; VanGeen, A.; Fuller, C.C.; Anima, R.J.
Attribution: Pacific
Sedimentary record of anthropogenic and biogenic polycyclic aromatic hydrocarbons in San Francisco Bay, California; 1999; Article; Journal; Marine Chemistry; Pereira, W. E.; Hostettler, F. D.; Luoma, S. N.; Van Geen, A.; Fuller, C. C.; Anima, R. J.

Year Published: 1999

Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose...

Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.
Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary; 1999; Article; Journal; Marine Chemistry; Ritson, P. I.; Bouse, R. M.; Flegal, A. R.; Luoma, S. N.

Year Published: 1999

The effect of infaunal bivalve grazing on phytoplankton bloom development in south San Francisco Bay

No abstract available.

Thompson, J.K.
Attribution: Pacific

Year Published: 1999

The impact of human activities on sediments of San Francisco Bay, California: an overview

This note introduces a set of eight papers devoted to a detailed study of two sediment cores from San Francisco Bay with an overview of the region and a chronology of human activities. Data used in this study to constrain the range of sediment ages at different depths include , and  concentrations in the sediment and the  ...

van Geen, Alexander; Luoma, Samuel N.
Attribution: Pacific

Year Published: 1999

The relative importance of light and nutrient limitation of phytoplankton growth: A simple index of coastal ecosystem sensitivity to nutrient enrichment

Anthropogenic nutrient enrichment of the coastal zone is now a well-established fact. However, there is still uncertainty about the mechanisms through which nutrient enrichment can disrupt biological communities and ecosystem processes in the coastal zone. For example, while some estuaries exhibit classic symptoms of acute eutrophication,...

Cloern, J.E.
The relative importance of light and nutrient limitation of phytoplankton growth: A simple index of coastal ecosystem sensitivity to nutrient enrichment; 1999; Conference Paper; Aquatic Ecology; Cloern, J. E.

Year Published: 1999

The spring runoff pulse from the Sierra Nevada

Just about every year there is one major first pulse of snowmelt runoff (streamflow) that marks the transition from winter to spring in high elevation, snowmelt driven watersheds in the western United States. As a index, we have used the record of relatively pristine streamflow at the Merced River, Happy Isles in Yosemite National Park to identify...

Cayan, D.R.; Peterson, D.H.; Riddle, L.; Dettinger, M.D.; Smith, R.
Attribution: Pacific

Year Published: 1999

Time series of suspended-solids concentration in Honker Bay during water year 1997

Suspended-solids concentration (SSC) responds differently to seasonal variations, such as Delta outflow and wind in shallow water areas than in deep-water channels. Although San Francisco Bay includes extensive areas of shallow water, with about one-half of the surface area of the Bay being less than 2 meters deep (Conomos and Peterson, 1977),...

Ruhl, Catherine A.; Schoellhamer, David H.
Attribution: Pacific

Year Published: 1999

United States streamflow probabilities based on forecasted La Nina, winter-spring 2000

Although for the last 5 months the TahitiDarwin Southern Oscillation Index (SOI) has hovered close to normal, the “equatorial” SOI has remained in the La Niña category and predictions are calling for La Niña conditions this winter. In view of these predictions of continuing La Niña and as a direct extension of...

Dettinger, M.D.; Cayan, D.R.; Redmond, K.T.
Attribution: Pacific

Year Published: 1999

Water-quality variability in San Francisco Bay: general patterns of change during 1997

The 1997 Annual Report is the fifth Annual Report from the Regional Monitoring Program for Trace Substances (RMP) and contains a comprehensive description of RMP results from the 1997 monitoring year. As in previous years, the report includes results from the Base Program (water, sediment, and bivalve monitoring) and results from Pilot and Special...

Cloern, J.E.; Cole, B.E.; Edmunds, J.L.; Baylosis, J.I.

Filter Total Items: 222
Moutain Diablo in the early morning
December 31, 2004

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Attribution: Pacific
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.
December 31, 2003

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

Attribution: Water Resources, Pacific
Evaportranspiration equipment along the Tracy Segment, Nevada
April 30, 2003

Evaportranspiration equipment along the Tracey Segment

Evaportranspiration equipment along the Tracey Segment

USGS regional research drill rig near Truckee River, NV
June 9, 2001

USGS regional research drill rig near Truckee River, NV

USGS regional research drill rig constructing sites near the south bank of the Truckee River just downstream of USGS 10350000 Truckee River at Vista. The wells were constructed to investigate surface water groundwater interaction.

Irrigation ditch alongside an agricultural field.
December 31, 2000

Irrigation ditch alongside an agricultural field in California's Central Valley

Irrigation systems in Central California Valley Ecoregion: Single-field irrigation ditch.

Attribution: Pacific
Grasslands and agricultural fields in the flat foreground, with housing development on the hills beyond.
December 31, 2000

Grasslands and agricultural fields, with housing development on the hills beyond.

Conversions of grassland/shrubland and agriculture to developed land were two common land-cover changes in Southern and Central California Chaparral and Oak Woodlands Ecoregion.

Attribution: Pacific

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