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Roberto J. Anima

Publications and source records attributed to Roberto J. Anima.

11 recordsLinked to original sources
USGS2008

Interferometric Sidescan Bathymetry, Sediment and Foraminiferal Analyses; a New Look at Tomales Bay, California

The United States Geological Survey (USGS) in collaboration with Point Reyes National Sea Shore (PRNS), and the Tomales Bay Watershed Council [http://www.tomalesbaywatershed.org/] has completed a detailed bathymetric survey, and sediment and foraminiferal analyses of the floor of Tomales Bay, California. The study goals are to detail the submarine morphology, the sediment distribution, sedimentary features, and distribution of foraminifera to provide a framework for future studies. The USGS collected swath bathymetric data with a SEA SWATHplus interferometric sidescan sonar system (2004, 2005) and an echo sounder system (2006). The data were processed into continuous mosaic images that show bathymetric detail of the bay floor with 0.2-m vertical and 4.0-m horizontal resolution. Acoustic backscatter data from the 2004 and 2005 surveys were processed into 2-m resolution grids. In addition, 27 sediment samples were collected from various parts of the bay for grain size analyses and a comprehensive study of the distribution of foraminifera in Tomales Bay. The foraminiferal analysis determined that the invasive foraminifera Trochammina hadai from Japan was present in Tomales Bay. The project was conducted in response to a request from the National Park Service, and the Tomales Bay Watershed Council who voiced a need to look at the environmental impacts of human input to the surrounding watersheds that ultimately flow into the bay. The mapping, sediment, and foraminiferal data establish a baseline survey for future comparisons of possible geologic and anthropogenic changes that might occur due to changes in land use or development in the surrounding watershed. These data may also aid in determining the possible pathways of pollutants entering the bay from the surrounding watersheds.

Open-File Report↗
USGS2007

Investigation of wind and water level for the Giacomini Wetland Restoration Project, Point Reyes National Seashore

Point Reyes National Seashore (PRNS), comprising unique elements of geological, biological, and historical interest, is located on the central California coast approximately 60 km northwest of San Francisco. The National Seashore contains nearly 130 km of exposed and protected shorelines, spectacular coastal cliffs and headlands, lagoons, open grasslands, bushy hillsides, and forested ridges. Approximately 30 km of the shoreline are coastal-dune habitat that supports 11 federally listed species, including the threatened western snowy plover and the endangered plants Tidestrom's lupine ( Lupinus tidestromii ) and beach layia ( Layia carnosa ). The San Andreas Fault, a right-lateral strike-slip fault, trends northwest along the northeastern side of the park. Tomales Bay, which is straight, long, narrow, and shallow, runs along the northeastern boundary of PRNS. The Bay, which fills the northwestern end of a rift valley at the intersection of the San Andreas Fault with the coastline, is approximately 20 km long, 2 km wide, and 6 m deep with mountainous terrain to the southwest and rolling hills to the northeast. Tomales Bay is one of the cleanest estuaries on the West Coast. In winter, approximately 17,000 to 20,000 shorebirds inhabit Tomales Bay and Bodega Bay, which lies directly to the north. At the head of Tomales Bay, the Giacomini Ranch comprises 563 acres of pastureland currently being used for grazing dairy cattle. After more than 50 years of operation as a dairy, the National Park Service acquired the Giacomini property with the intention to restore most of it and the nearby Olema Marsh to tidal wetland. Restoration will add approximately 4% to the existing coastal wetlands in California. The project will return the headwaters of Tomales Bay and two major stream intersections to an intertidal marsh environment, enhancing habitat for both wildlife and fish populations and contributing to the long-term health of Tomales Bay. Prior to the establishment of the ranch, the area was primarily salt marsh that formed as the delta of Lagunitas Creek expanded into Tomales Bay. In converting the salt marsh to dairy land, levees and tide gates were constructed to prevent tidal incursion and stream flooding. Those levees have significantly altered the patterns of estuarine circulation and sediment deposition. To restore natural hydrologic processes within the area and to promote the return of ecological functions and processes, the levees will have to be breached or removed. Developing a successful restoration strategy requires knowledge of elevations within the pastureland and the range of water depths that can be expected from tidal, river, and wind action. In support of the restoration program, the USGS provides technical assistance to PRNS in the form of a scientific study focusing on understanding the physical processes that could affect the Giacomini wetland restoration. The study will yield scientific products that NPS resource managers can use in designing and implementing the restoration project. Research elements include: - Develop a Geodetic Control Network (GCN) throughout PRNS that meets the standards specified National Geodetic Survey data base (the NGS "Bluebook"). The grid will allow this and future studies to be conducted to a precision commensurate with the expressed goals of PRNS. The survey will consist of three steps: (1) verify existing GPS control monuments in the area; (2) tie control monuments in the study areas to the GPS control monuments; and (3) establish NAVD88 elevations using a digital electronic level. - Conduct a detailed survey of the Giacomini site to produce an accurate topographic map of the property. The site survey can be coupled with on-site water-level measurements to produce an empirical flooding model. - Measure water level and wind regime at the Giacomini site. The water-level range is critical to determining the wetland types based on the elevation of the dairy land. Water level at Sacramento Landing, in central Tomales Bay, will also be measured for comparison. As of November 2005, we have created a GCN, produced a detailed topographic map of the Giacomini site, and collected approximately three years of water-level and wind data at the Giacomini site and over one year of usable water-level data at the Sacramento Landing pier.

California↗
USGS2006

Benthic habitat and geologic mapping of the outer continental shelf of north-central California

The Fanny Shoal area is located between North Farallon Island and Cordell Bank approximately 40 miles west of San Francisco, California. The area lies within the Gulf of the Farallones National Marine Sanctuary (GFNMS) which is located just a few miles from San Francisco. The waters within the GFNMS are part of a nationally significant marine ecosystem encompassing a diversity of highly productive marine habitats. Protection of the living and cultural resources at the sites are administered by the National Oceanic and Atmospheric Administration (NOAA). The U.S. Geological Survey (USGS) in cooperation with the Golden Gate National Recreation Area (GGNRA) and NOAA, including the GFNMS, and Monterey Bay National Marine Sanctuary (MBNMS), collected side-scanning sonar, and underwater video data over three cruises in July of 2003, and April of 2004. The data are consolidated into a geographic information system (GIS) to produce benthic habitat and geologic maps that provide researchers and those involved in decision making with crucial, georeferenced geologic information that will aid in preserving the area's environment.

California↗
USGS2005

Locations and descriptions of gravity, box, and push cores collected in San Francisco Bay between January and February, 1990 and 1991

A project to study San Francisco Bay sediments collected over 300 sediment gravity cores; six push cores, and three box cores in San Francisco Bay during the years 1990-91. The purpose of the sampling effort is to establish a database on the Holocene sediment history of the bay. The samples described and mapped are the first effort to catalog and present the data collected. Thus far the cores have been utilized in various cooperative studies with state colleges and universities, and other USGS divisions. These cores serve as a base for ongoing multidisciplinary studies. The sediment studies project has initiated subsequent coring efforts within the bay using refined coring techniques to attain deeper cores.

California↗
USGS2003

Grand Canyon riverbed sediment changes, experimental release of September 2000 - a sample data set

An experimental water release from the Glen Canyon Dam into the Colorado River above Grand Canyon was conducted in September 2000 by the U.S. Bureau of Reclamation. The U.S. Geological Survey (USGS) conducted sidescan sonar surveys between Glen Canyon Dam (mile -15) and Diamond Creek (mile 220), Arizona (mile designations after Stevens, 1998) to determine the sediment characteristics of the Colorado River bed before and after the release. The first survey (R3-00-GC, 28 Aug to 5 Sep 2000) was conducted before the release when the river was at its Low Summer Steady Flow (LSSF) of 8,000 cfs. The second survey (R4-00-GC, 10 to 18 Sep 2000) was conducted immediately after the September 2000 experimental release when the average daily flow was as high as 30,800 cfs as measured below Glen Canyon Dam (Figure 2). Riverbed sediment properties interpreted from the sidescan sonar images include sediment type and sandwaves; overall changes in these properties between the two surveys were calculated. Sidescan sonar data from the USGS surveys were processed for segments of the Colorado River from Glen Canyon Dam (mile -15) to Phantom Ranch (mile 87.7, Figure 3). The surveys targeted pools between rapids that are part of the Grand Canyon Monitoring and Research Center (GCMRC http://www.gcmrc.gov/ ) physical sciences study. Maps interpreted from the sidescan sonar images show the distribution of sediment types (bedrock, boulders, pebbles or cobbles, and sand) and the extent of sandwaves for each of the pre- and post-flow surveys. The changes between the two surveys were calculated with spatial arithmetric and had properties of fining, coarsening, erosion, deposition, and the appearance or disappearance of sandwaves.

Arizona↗
USGS2000

Seafloor Rocks and Sediments of the Continental Shelf From Monterey Bay to Point Sur, California

Introduction Acoustic swath mapping of the greater Monterey Bay area continental shelf from Point Ano Nuevo to Point Sur reveals complex patterns of rock outcrops on the shelf, and coarse sand bodies that occur in distinct depressions on the inner and mid-shelves. This publication portrays the seafloor components in a 36- by 48-inch map sheet at 1:100,000 scale.

Miscellaneous Field Studies Map↗
USGS1985

RECOVERY OF MONTEREY BAY BEACHES AFTER THE WINTER STORMS OF 1982-83.

The El Nino conditions of 1982 and 1983 produced unusually frequent and intense storms along the central California coast. These storms produced much greater than normal beach erosion in Monterey Bay, causing extensive damage to coastal structures, erosion of coastal cliffs, and loss of sand from coastal dunes. The beaches accreted during the summer of 1983 and eroded again the next winter. Every beach, however, showed its own pattern of rebuilding; the eigenfunction analysis showed that the beaches did not all reach either their maximum or minimum volumes at the same time.

Conference Paper↗
USGS1985

SURVEYS OF COASTAL STRUCTURES USING GEOPHYSICAL TECHNIQUES.

During the summer of 1983 and the spring and summer of 1984, the authors conducted side scan sonar and shallow subbottom surveys in conjunction with bathymetric and diving surveys along three northern California coastal structures to determine the condition of the structures before extensive damage occurred. Then the applicability of the data collection techniques for condition surveys in general was evaluated. Two of the structures surveyed are the parallel jetties that protect the entrance to Humboldt Bay, California, and the third structure is the outer breakwater at Crescent City, California. It was found that the side scan sonar is an excellent tool for defining the toe of the structure; also, when waves are low, it can be useful in determining armor types and the slope of structures. The subbottom system provided information on fault and bedrock locations; however, other systems need to be tested to see if any of them can locate buried armor near the structures.

Conference Paper↗