Regions L2 Landing Page Tabs
Napa-Sonoma marshes pond 3, hydrologic and biotic changes in a salt pond following breachingAthearn, N.D.; Goodenough, K.; Takekawa, John Y.; Miles, A.K.; Saiki, M.K.; Spring, S.; Mejia, F.; Shellenbarger, G.G.; Schoellhamer, D.H.
Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto regional water quality control plant in south San Francisco Bay, California: 2004Moon, Edward; Shouse, Michelle K.; Parcheso, Francis; Thompson, Janet K.; Luoma, Samuel N.; Cain, Daniel J.; Hornberger, Michelle I.
River chemistry as a monitor of Yosemite Park mountain hydroclimates
High-frequency, high-altitude measurements of water chemistry provide insights into processes relating to the hydrology, climate, and geochemistry of mountain catchments. When such observations are combined with stream stage, temperature, snow, weather, and other surface hydroclimate measurements, they are particularly useful in allowing...Peterson, David; Smith, Richard; Hager, Stephen; Hicke, Jeffrey A.; Dettinger, Michael; Huber, King
Snowmelt discharge characteristics Sierra Nevada, California
Alpine snow is an important water resource in California and the western U.S. Three major features of alpine snowmelt are the spring pulse (the first surge in snowmelt-driven river discharge in spring), maximum snowmelt discharge, and base flow (low river discharge supported by groundwater in fall). A long term data set of hydrologic measurements...Peterson, David; Smith, Richard; Stewart, Iris; Knowles, Noah; Soulard, Chris; Hager, Stephen
Recent changes toward earlier springs---early signs of climate warming in western North AmericaCayan, D.; Dettinger, M.; Stewart, I.; Knowles, N.
From climate-change spaghetti to climate-change distributions for 21st Century California
The uncertainties associated with climate-change projections for California are unlikely to disappear any time soon, and yet important long-term decisions will be needed to accommodate those potential changes. Projection uncertainties have typically been addressed by analysis of a few scenarios, chosen based on availability or to capture the...Dettinger, M.D.
Heat wave brings an unprecedented red tide to San Francisco Bay
An exceptional red tide in San Francisco Bay was observed on 8 September 2004. The red tide had chlorophyll concentrations approaching 200 mg/m3 (Figure 1) in red/purple surface streaks containing high abundances of the dinoflagellate Akashiwo sanguinea. Red tides and harmful algal blooms (HABs) are common features of coastal...Cloern, James E.; Schraga, Tara S.; Lopez, Cary B.
Summary of suspended-sediment concentration data, San Francisco Bay, California, Water Year 2003
Suspended-sediment concentration data were collected in San Francisco Bay during water year 2003 (October 1, 2002-September 30, 2003). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, three sites in San Pablo Bay, one site in Central San Francisco Bay, and three sites in South San...Buchanan, Paul A.; Ganju, Neil K.
A long-term (50 yr) historical perspective on flood-generating winter storms in the American River basin
No abstract available.Dettinger, M.D.
Bay sediment budget: Sediment accounting 101
Comparison of a budget developed for 1955-1990 with a budget developed for 1995- 2002 showed decreasing sediment inflow and increased amounts leaving the Bay to upland disposal and sand mining, resulting in an increased rate of erosion of sediment from the Bay floor Finding a way to shift disposal from the Ocean back to the Bay could provide...Schoellhamer, David H.; Lionberger, Megan A.; Jaffe, Bruce E.; Ganju, Neil K.; Wright, Scott A.; Shellenbarger, Gregory
Climate anomalies generate an exceptional dinoflagellate bloom in San Francisco Bay
We describe a large dinoflagellate bloom, unprecedented in nearly three decades of observation, that developed in San Francisco Bay (SFB) during September 2004. SFB is highly enriched in nutrients but has low summer‐autumn algal biomass because wind stress and tidally induced bottom stress produce a well mixed and light‐limited pelagic habitat....Cloern, J.E.; Schraga, T.S.; Lopez, C.B.; Knowles, N.; Grover, Labiosa R.; Dugdale, R.
Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta
Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal...Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.
Rock falls in California’s Sierra Nevada - Pursuing explanations for exfoliation and seemingly spontaneous fracture of rock
All clips show the deck of a barge in San Pablo Bay, California.
- Clip 1 - USGS technicians lower and raise a grab sampler
- Clips 2, 3, 4 - USGS technicians lower and raise a vibracore
- Clip 5 - Tanker passes as USGS technicians work on anchor lines
- Clip 6 - USGS technicians raise anchor, while another works on a vibracore tube
Interviews with staff at Point Reyes National Seashore tell how this National Park Service unit uses USGS science to educate visitors, and manage the park.
Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
With Margaret Mangan, Scientist-in-Charge,...
Stunning 4K aerial and ground b-roll of the Kīlauea Volcano Halemaʻumaʻu Crater Summit Vent Lava Lake taken between July 24 and July 31, 2016.
Here is the shotlist:
00:11 Kīlauea summit lava lake spatter, night, medium shot
00:33 Lava lake spatter, night medium shot
00:43 Lava lake wide shot, night, spatter on right of frame
1:01 Wide shot,
Though difficult to photograph, aerial views showed that this open vent was but a small window into a large, hot cavity beneath Puʻu ʻŌʻō's northeast flank in Hawaii Inside, streams of lava from an unseen source (or sources) closer to the crater rim (visible at lower right) were cascading toward the upper left into unknown depths. This view, looking almost straight down,...
USGS research geologist Kate Scharer with her finger on the Fairweather Fault in southeast Alaska. The magnitude 7.8 Lituya Bay earthquake caused shaking that toppled trees along the fault, which left a break in the forest shown here.
Nearly 60 years after a magnitude 7.7 earthquake struck Lituya Bay, Alaska — leading to a tsunami that devastated the area — six U.S. Geological Survey geologists revisited the isolated region of Alaska, to pick up where their scientific predecessors left off. In this photo, members of the USGS research team pause to take in the view of South Crillon Glacier from a study...
Trench site along the southern Fairweather Fault, in Glacier Bay National Park, Alaska. The alluvial fan at left consists of lake, stream channel and debris flow deposits impounded by the Fairweather Fault scarp, at right.
Research and technical support provided by USGS makes a difference Some recent press releases and media advisories from the Pacific Region are highlighted below.
New evidence for frequent large tsunamis at a remote island near Dutch Harbor, Alaska provides geological data to aid tsunami hazard preparedness efforts around the Pacific Rim.
A new study completed by the U.S. Geological Survey, in cooperation with the Borrego Water District, will help water planners in the Borrego Valley, California better understand and manage the groundwater resources that the area relies on for drinking water, agriculture and recreation.
Joint Venture Silicon Valley and the U.S. Geological Survey today jointly announced a partnership to address regional challenges from natural hazards, climate and land use change, and continued availability of clean air and water resources.
MENLO PARK, Calif. — U.S. Geological Survey employees in Menlo Park, Calif. will participate in an earthquake safety drill, and test their emergency response plan as part of the Great ShakeOut on Oct. 15, an annual day of action to practice how to protect yourself from an earthquake.
Fumaroles are openings in the earth’s surface that emit steam and volcanic gases, such as sulfur dioxide and carbon dioxide. They can occur as holes, cracks, or fissures near active volcanoes or in areas where magma has risen into the earth’s crust without erupting. A fumarole can vent for centuries or quickly go extinct, depending on the longevity of its heat source.
This year, groundwater levels in many wells in California’s Central Valley are at or below historical low levels. In addition, from 2007 through 2015, land subsidence that correlates to areas with large groundwater level declines has strongly increased in two large agricultural areas near the towns of El Nido and Pixley, according to a new article by the U.S. Geological Survey.
Islands used by tropical seabirds are highly vulnerable to sea level rise according to a new study released today.
Scientists at the U.S. Geological Survey Hawaiian Volcano Observatory have elevated the Volcano Alert Level for Mauna Loa from NORMAL to ADVISORY. This change in status indicates that the volcano is showing signs of unrest that are above known background levels, but it does not mean that a Mauna Loa eruption is imminent or certain.
OAKHURST, Calif. -- Overall fire threats to greater sage-grouse habitat are much higher in the western part of the species’ range than in the eastern part, according to a U.S. Geological Survey fire threats assessment study published today.
One winter's night in the year 1700, a mysterious tsunami flooded fields and washed away houses in Japan. It arrived without the warning that a nearby earthquake usually provides.
Three new sets of maps detail the offshore bathymetry, habitats, geology and submarine environment of the seafloor off the coast of San Francisco, Drakes Bay, and Tomales Point.
Landslides are common along the rugged Big Sur coast in central California
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.