San Francisco Bay Bathymetry Completed
USGS research vessel Parke Snavely
Collecting bathymetry in Alviso Slough, south San Francisco Bay, in 2011
Bathymetry of a dynamic tidal estuary, such as San Francisco Bay, provides the observable linkage between anthropogenic modifications of the landscape—such as evolving land use practices, flood control, and water diversions—and natural forces of climate-driven river flow, sea level change, tides, and wind. By examining our record of hydrographic surveys, spanning over 150 years, we can gain insights into the probable effect of future modification including efforts toward restoration.
In addition to historical change analysis, current bathymetry is critical for the calibration and interpretation of hydrodynamic and ecological models. Mass balance and sheer stress are driven by bathymetry—even ecological niches are influenced by bathymetry (depth, turbidity, particle size, light, turbulence, etc.).
Here, we provide information about the bathymetric data available for San Francisco Bay.
Methods
In the example sequence shown below, the first step in the preparation of regular grids displayed on this web site begins with irregular hydrographic survey data (soundings) that have been corrected to a common datum (1).
The National Oceanic and Atmospheric Administration (NOAA) is the primary resource for obtaining these original soundings. Other agencies, including the US Army Corps of Engineers, California Department of Water Resources, US Bureau of Reclamation, and the USGS, have contributed local studies. Once the soundings are in hand they are contoured, and shoreline and marsh perimeters are added and combined into a geographic information system (GIS) (2).
All data layers must be adjusted to a common horizontal and vertical datum and all depths must have the same orientation and units. At this point a grid can be generated.
Quality control is an iterative process, performed on the resulting grid by comparing it with the original soundings (3, 4).
Errors are computed, plotted and repaired when appropriate. Errors are usually a result of incorrect unit tags on the source data or digitizing mistakes, but some are due to gradients in bathymetry that cannot be resolved by a single grid cell.
The final grid (5) can be adjusted to a different tidal datum using an adjustment grid.
This grid is produced by assigning tide levels observed at shore stations to co-tidal lines from the TRIM-2D model (6, 7).
Geostatistics
Using this 100m grid cell representation of the Bay we can compute some primary geomorphic features of the basin--such as surface area and volume--for a given tidal datum, and compare these and other statistical properties in the sub-basins of San Francisco Bay.
Full Bay
TIDAL DATUM | VOLUME (Mm3) | SURFACE AREA (Mm2) | AVG. DEPTH VOL/AREA (m) |
MEDIAN DEPTH (m) |
MLLW | 7142 | 1138 | 6.3 | 2.8 |
MSL | 8446 | 1219 | 6.9 | 3.6 |
MHHW | 9570 | 1244 | 7.7 | 4.4 |
Properties based on the Mean Sea Level grid
PROPERTY | SOUTH BAY | CENTRAL BAY | SAN PABLO BAY | SUISUN BAY |
Area (Mm2) | 426.8 | 326.3 | 273.4 | 169.6 |
Volume (Mm3) | 1971 | 4388 | 1016 | 990 |
Average depth (m) | 4.6 | 13.4 | 3.7 | 5.8 |
Median depth (m) | 3.2 | 10.9 | 2.5 | 3.6 |
% Area < 5 m |
69 | 32 | 82 | 57 |
Bathymetry Change
As described in our METHODS section, a continuous surface representation of each bathymetric survey was created using Topogrid, an Arc/Info module that utilizes sounding and contour information to create a hydrodynamically correct surface. Input data was a combination of point soundings and hand-drawn depth contours (see table below). Once a bathymetric surface has been created for each hydrographic survey, the surfaces are adjusted to a common datum and we compute change or difference grids. These new ‘change’ surfaces identify areas of erosion and deposition.
Here is an example difference map of San Pablo Bay (1856-1887). During this period there was massive sediment accumulation related to hydraulic gold mining.
The data supporting historical change analysis is quite extensive. The following tables summarize the survey dates, digitized soundings, and contours used to produce the bathymetric surfaces and difference maps for San Francisco Bay.
SUISUN BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1867 | 18,202 | -4, 0, 6, 12, 18, 30, 60, 90 |
1887 | 21,753 | -4, 0, 6, 12, 18, 30, 60, 90 |
1922 | 17,303 | -4, 0, 6, 12, 18, 30, 60, 90 |
1942 | 36,169 | -4, 0, 6, 12, 18, 30, 60, 90 |
1990 | 93,393 | -1, 2, 5, 10, 15, 20, 25, 30, 35, 45 (meters) |
SAN PABLO BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1856 | 4973 | 0, 2, 3, 4, 6, 12, 18, 24, 36, 42, 48, 60 |
1887 | 3679 | -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 12, 24, 30, 36, 48, 60 |
1898 | 1994 | 0, 3, 6, 12, 18, 24, 30, 36, 60 |
1922 | 42,764 | -1, 0, 1, 2, 3, 4, 5, 6, 12, 18, 30, 60 |
1951 | 62,900 | 0, 6, 12, 30, 48 |
1983 | 65,739 | 0, 6, 12, 18, 30, 36, 60 |
CENTRAL BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1855 | 21,052 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 |
1895 | 289,282 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 |
1920 | 48,116 | 0, 6, 12, 18, 30, 60, 90, 120 |
1947 | 229,551 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 |
1979 | 177,144 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 |
SOUTH BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1858 | 20,036 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70 |
1898 | 99,399 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1931 | 92,451 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1956 | 100,748 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1983 | 136,095 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
2005 | ~2.7 million | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
Official Publications
- San Pablo Bay Historical Analysis
USGS Open-File Report 98-759
Sedimentation and bathymetric change in San Pablo Bay, 1856-1983
- Suisun Bay Historical Analysis
USGS Open-File Report 99-563
Sedimentation and Bathymetry Changes in Suisun Bay: 1867-1990
- Central Bay Historical Analysis
USGS Open-File Report 2008-1312
Sediment Deposition, Erosion, and Bathymetric Change in Central San Francisco Bay: 1855–1979
- South Bay Historical Analysis Part 1
USGS Open-File Report 2004-1192
Deposition, Erosion, and Bathymetric Change in South San Francisco Bay: 1858-1983
- South Bay Historical Analysis Part 2
USGS Open-File Report 2006-1287
Sediment Deposition and Erosion in South San Francisco Bay, California from 1956 to 2005
Animations of change for North Bay
By linear interpolation, we can compute sedimentation maps for years between surveys and combine the maps to produce an animation of sedimentation for the North Bay. This animation gives an overall view of the system in time and space. We can see that, in the more active channels of Suisun Bay, surface sediment is deposited and erodes quickly in response to changing flows (floods/drought) and modifications (such as dredging the southern channel or long term mooring of the mothball fleet).
We assume:
- the sediment deposited in North San Francisco Bay between 1856 and 1887 was dominated by hydraulic mining debris;
- erosion observed in subsequent surveys was not re-deposited locally; and
- material deposited after 1887 was not mining debris.
Making these assumptions, we can predict the location and thickness of the original hydraulic mining debris. It is especially notable that the mercury employed in gold mining in the Sierra Nevada was refined liquid quicksilver or elemental mercury; this is a form of mercury much more likely to foster net methylation than is cinnabar, the form of mercury in most mercury mines. Approximately 10,000 tonnes of refined mercury were lost to the watershed during the Gold Rush mining era. Much of the mercury consumed by gold mining could have been incorporated into the 12 billion cubic meters of sediments extracted by the mining activities and released to the rivers of the Bay-Delta watershed. The mercury-laced hydraulic mining debris was ultimately transported to the bay-delta; it is known that large deposits of hydraulic mining debris remain in bay sediments. These wastes formed marshes, islands, or filled or diked marsh, or were deposited in shallow waters. Under the right circumstances this mercury contamination is transported through the food chain and concentrated in some commercial and sport fish. Human consumption of fish caught in the Bay is already restricted because of mercury contamination. Specifically, adults are advised to limit consumption of sport fish from the Bay to two times a month; pregnant or nursing women and children 6 or under should limit consumption to one time a month. Large shark and striped bass from the Bay should not be consumed at all. As we study the feasibility of restoration of marshes that were sinks for mining debris, the possibility of releasing mercury to the Bay must be considered.
Animations of mining debris deposition and subsequent erosion
Below are publications associated with this project.
Spatial trends in tidal flat shape and associated environmental parameters in South San Francisco Bay
Mercury-contaminated hydraulic mining debris in San Francisco Bay
Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2006
Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Sediment deposition, erosion, and bathymetric change in central San Francisco Bay: 1855-1979
Dual-RiverSonde measurements of two-dimensional river flow patterns
Complex seasonal patterns of primary producers at the land-sea interface
High-resolution foraminiferal, isotopic, and trace element records from holocene estuarine deposits of San Francisco Bay, California
Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2005
2005 hydrographic survey of south San Francisco Bay, California
Reconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California
Surface temperature patterns in complex terrain: Daily variations and long-term change in the central Sierra Nevada, California
Below are partners associated with this project.
- Overview
Bathymetry of a dynamic tidal estuary, such as San Francisco Bay, provides the observable linkage between anthropogenic modifications of the landscape—such as evolving land use practices, flood control, and water diversions—and natural forces of climate-driven river flow, sea level change, tides, and wind. By examining our record of hydrographic surveys, spanning over 150 years, we can gain insights into the probable effect of future modification including efforts toward restoration.
In addition to historical change analysis, current bathymetry is critical for the calibration and interpretation of hydrodynamic and ecological models. Mass balance and sheer stress are driven by bathymetry—even ecological niches are influenced by bathymetry (depth, turbidity, particle size, light, turbulence, etc.).
Here, we provide information about the bathymetric data available for San Francisco Bay.
Methods
Sources/Usage: Public Domain. View Media DetailsIn the example sequence shown below, the first step in the preparation of regular grids displayed on this web site begins with irregular hydrographic survey data (soundings) that have been corrected to a common datum (1).
The National Oceanic and Atmospheric Administration (NOAA) is the primary resource for obtaining these original soundings. Other agencies, including the US Army Corps of Engineers, California Department of Water Resources, US Bureau of Reclamation, and the USGS, have contributed local studies. Once the soundings are in hand they are contoured, and shoreline and marsh perimeters are added and combined into a geographic information system (GIS) (2).
All data layers must be adjusted to a common horizontal and vertical datum and all depths must have the same orientation and units. At this point a grid can be generated.
Quality control is an iterative process, performed on the resulting grid by comparing it with the original soundings (3, 4).
Errors are computed, plotted and repaired when appropriate. Errors are usually a result of incorrect unit tags on the source data or digitizing mistakes, but some are due to gradients in bathymetry that cannot be resolved by a single grid cell.
The final grid (5) can be adjusted to a different tidal datum using an adjustment grid.
This grid is produced by assigning tide levels observed at shore stations to co-tidal lines from the TRIM-2D model (6, 7).
Geostatistics
Using this 100m grid cell representation of the Bay we can compute some primary geomorphic features of the basin--such as surface area and volume--for a given tidal datum, and compare these and other statistical properties in the sub-basins of San Francisco Bay.
Sources/Usage: Public Domain. View Media DetailsSources/Usage: Public Domain. View Media DetailsFull Bay
TIDAL DATUM VOLUME (Mm3) SURFACE AREA (Mm2) AVG. DEPTH
VOL/AREA (m)MEDIAN DEPTH (m) MLLW 7142 1138 6.3 2.8 MSL 8446 1219 6.9 3.6 MHHW 9570 1244 7.7 4.4 Properties based on the Mean Sea Level grid
PROPERTY SOUTH BAY CENTRAL BAY SAN PABLO BAY SUISUN BAY Area (Mm2) 426.8 326.3 273.4 169.6 Volume (Mm3) 1971 4388 1016 990 Average depth (m) 4.6 13.4 3.7 5.8 Median depth (m) 3.2 10.9 2.5 3.6 % Area
< 5 m69 32 82 57 Bathymetry Change
As described in our METHODS section, a continuous surface representation of each bathymetric survey was created using Topogrid, an Arc/Info module that utilizes sounding and contour information to create a hydrodynamically correct surface. Input data was a combination of point soundings and hand-drawn depth contours (see table below). Once a bathymetric surface has been created for each hydrographic survey, the surfaces are adjusted to a common datum and we compute change or difference grids. These new ‘change’ surfaces identify areas of erosion and deposition.
Here is an example difference map of San Pablo Bay (1856-1887). During this period there was massive sediment accumulation related to hydraulic gold mining.
The data supporting historical change analysis is quite extensive. The following tables summarize the survey dates, digitized soundings, and contours used to produce the bathymetric surfaces and difference maps for San Francisco Bay.
SUISUN BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1867 18,202 -4, 0, 6, 12, 18, 30, 60, 90 1887 21,753 -4, 0, 6, 12, 18, 30, 60, 90 1922 17,303 -4, 0, 6, 12, 18, 30, 60, 90 1942 36,169 -4, 0, 6, 12, 18, 30, 60, 90 1990 93,393 -1, 2, 5, 10, 15, 20, 25, 30, 35, 45 (meters) SAN PABLO BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1856 4973 0, 2, 3, 4, 6, 12, 18, 24, 36, 42, 48, 60 1887 3679 -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 12, 24, 30, 36, 48, 60 1898 1994 0, 3, 6, 12, 18, 24, 30, 36, 60 1922 42,764 -1, 0, 1, 2, 3, 4, 5, 6, 12, 18, 30, 60 1951 62,900 0, 6, 12, 30, 48 1983 65,739 0, 6, 12, 18, 30, 36, 60 CENTRAL BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1855 21,052 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 1895 289,282 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 1920 48,116 0, 6, 12, 18, 30, 60, 90, 120 1947 229,551 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 1979 177,144 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 SOUTH BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1858 20,036 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70 1898 99,399 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1931 92,451 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1956 100,748 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1983 136,095 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 2005 ~2.7 million 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 Official Publications
- San Pablo Bay Historical Analysis
USGS Open-File Report 98-759
Sedimentation and bathymetric change in San Pablo Bay, 1856-1983
- Suisun Bay Historical Analysis
USGS Open-File Report 99-563
Sedimentation and Bathymetry Changes in Suisun Bay: 1867-1990
- Central Bay Historical Analysis
USGS Open-File Report 2008-1312
Sediment Deposition, Erosion, and Bathymetric Change in Central San Francisco Bay: 1855–1979
- South Bay Historical Analysis Part 1
USGS Open-File Report 2004-1192
Deposition, Erosion, and Bathymetric Change in South San Francisco Bay: 1858-1983
- South Bay Historical Analysis Part 2
USGS Open-File Report 2006-1287
Sediment Deposition and Erosion in South San Francisco Bay, California from 1956 to 2005
Animations of change for North Bay
Sources/Usage: Public Domain. View Media DetailsBy linear interpolation, we can compute sedimentation maps for years between surveys and combine the maps to produce an animation of sedimentation for the North Bay. This animation gives an overall view of the system in time and space. We can see that, in the more active channels of Suisun Bay, surface sediment is deposited and erodes quickly in response to changing flows (floods/drought) and modifications (such as dredging the southern channel or long term mooring of the mothball fleet).
We assume:
- the sediment deposited in North San Francisco Bay between 1856 and 1887 was dominated by hydraulic mining debris;
- erosion observed in subsequent surveys was not re-deposited locally; and
- material deposited after 1887 was not mining debris.
Making these assumptions, we can predict the location and thickness of the original hydraulic mining debris. It is especially notable that the mercury employed in gold mining in the Sierra Nevada was refined liquid quicksilver or elemental mercury; this is a form of mercury much more likely to foster net methylation than is cinnabar, the form of mercury in most mercury mines. Approximately 10,000 tonnes of refined mercury were lost to the watershed during the Gold Rush mining era. Much of the mercury consumed by gold mining could have been incorporated into the 12 billion cubic meters of sediments extracted by the mining activities and released to the rivers of the Bay-Delta watershed. The mercury-laced hydraulic mining debris was ultimately transported to the bay-delta; it is known that large deposits of hydraulic mining debris remain in bay sediments. These wastes formed marshes, islands, or filled or diked marsh, or were deposited in shallow waters. Under the right circumstances this mercury contamination is transported through the food chain and concentrated in some commercial and sport fish. Human consumption of fish caught in the Bay is already restricted because of mercury contamination. Specifically, adults are advised to limit consumption of sport fish from the Bay to two times a month; pregnant or nursing women and children 6 or under should limit consumption to one time a month. Large shark and striped bass from the Bay should not be consumed at all. As we study the feasibility of restoration of marshes that were sinks for mining debris, the possibility of releasing mercury to the Bay must be considered.
Animations of mining debris deposition and subsequent erosion
Sources/Usage: Public Domain. View Media DetailsSources/Usage: Public Domain. View Media Details - San Pablo Bay Historical Analysis
- Publications
Below are publications associated with this project.
Filter Total Items: 446Spatial trends in tidal flat shape and associated environmental parameters in South San Francisco Bay
Spatial trends in the shape of profiles of South San Francisco Bay (SSFB) tidal flats are examined using bathymetric and lidar data collected in 2004 and 2005. Eigenfunction analysis reveals a dominant mode of morphologic variability related to the degree of convexity or concavity in the cross-shore profileindicative of (i) depositional, tidally dominant or (ii) erosional, wave impacted conditionsAuthorsJ.A. Bearman, Carl T. Friedrichs, B. E. Jaffe, A.C. FoxgroverMercury-contaminated hydraulic mining debris in San Francisco Bay
The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercurycontaminated sediment created by hydraulic gold mining in the SieAuthorsRobin M. Bouse, Christopher C. Fuller, Samuel N. Luoma, Michelle I. Hornberger, Bruce E. Jaffe, Richard E. SmithSummary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2006
Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water-year 2006 (October 1, 2005-September 30, 2006). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, one site in San Pablo Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors werAuthorsPaul A. Buchanan, Megan A. LionbergerCalibration 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 concentratioAuthorsN. K. Ganju, D. H. SchoellhamerSediment deposition, erosion, and bathymetric change in central San Francisco Bay: 1855-1979
Central San Francisco Bay is the hub of a dynamic estuarine system connecting the San Joaquin and Sacramento River Deltas, Suisun Bay, and San Pablo Bay to the Pacific Ocean and South San Francisco Bay. To understand the role that Central San Francisco Bay plays in sediment transport throughout the system, it is necessary to first determine historical changes in patterns of sediment deposition andAuthorsTheresa A. Fregoso, Amy C. Foxgrover, Bruce E. JaffeDual-RiverSonde measurements of two-dimensional river flow patterns
Two-dimensional river flow patterns have been measured using a pair of RiverSondes in two experiments in the Sacramento-San Joaquin River Delta system of central California during April and October 2007. An experiment was conducted at Walnut Grove, California in order to explore the use of dual RiverSondes to measure flow patterns at a location which is important in the study of juvenile fish migrAuthorsC.C. Teague, D.E. Barrick, P.M. Lilleboe, Ralph T. Cheng, Paul Stumpner, Jon R. BurauComplex seasonal patterns of primary producers at the land-sea interface
Seasonal fluctuations of plant biomass and photosynthesis are key features of the Earth system because they drive variability of atmospheric CO2, water and nutrient cycling, and food supply to consumers. There is no inventory of phytoplankton seasonal cycles in nearshore coastal ecosystems where forcings from ocean, land and atmosphere intersect. We compiled time series of phytoplankton biomass (cAuthorsJ. E. Cloern, A.D. JassbyHigh-resolution foraminiferal, isotopic, and trace element records from holocene estuarine deposits of San Francisco Bay, California
A 3.5-m gravity core (DJ6-93SF-6) from San Francisco Bay reveals a complex paleoclimatic history of the region over the last 3870 cal YBP. A polynomial equation based on 11 AMS 14C ages provides an excellent age model for the core, and environmental proxies for water temperature and salinity are derived from various foraminiferal abundances, stable carbon and oxygen isotopes, and Mg/Ca ratios. TwoAuthorsM. McGannSummary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2005
Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2005 (October 1, 2004-September 30, 2005). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. SensoAuthorsPaul A. Buchanan, Megan A. Lionberger2005 hydrographic survey of south San Francisco Bay, California
An acoustic hydrographic survey of South San Francisco Bay (South Bay) was conducted in 2005. Over 20 million soundings were collected within an area of approximately 250 sq km (97 sq mi) of the bay extending south of Coyote Point on the west shore, to the San Leandro marina on the east, including Coyote Creek and Ravenswood, Alviso, Artesian, and Mud Sloughs. This is the first survey of this scalAuthorsAmy C. Foxgrover, Bruce E. Jaffe, Gerald T. Hovis, Craig A. Martin, James R. Hubbard, Manoj R. Samant, Steve M. SullivanReconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California
Sediment age profiles reconstructed from a sequence of historical bathymetry changes are used to investigate the subsurface distribution of historical sediments in a subembayment of the San Francisco Estuary. Profiles are created in a grid-based GIS modeling program that stratifies historical deposition into temporal horizons. The model's reconstructions are supported by comparisons to profiles ofAuthorsShawn A. Higgins, Bruce E. Jaffe, Christopher C. FullerSurface temperature patterns in complex terrain: Daily variations and long-term change in the central Sierra Nevada, California
A realistic description of how temperatures vary with elevation is crucial for ecosystem studies and for models of basin-scale snowmelt and spring streamflow. This paper explores surface temperature variability using temperature data from an array of 37 sensors, called the Yosemite network, which traverses both slopes of the Sierra Nevada in the vicinity of Yosemite National Park, California. ThesAuthorsJ.D. Lundquist, D.R. Cayan - Partners
Below are partners associated with this project.