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USGS2005

Coastal-change and glaciological map of the Ronne Ice Shelf area, Antarctica, 1974-2002

Changes in the area and volume of polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level may severely impact the densely populated coastal regions on Earth. Melting of the West Antarctic part alone of the Antarctic ice sheet could cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m (Lythe and others, 2001) to 73 m (Williams and Hall, 1993). In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known for certain whether the ice sheet is growing or shrinking. In a review paper, Rignot and Thomas (2002) concluded that the West Antarctic part of the Antarctic ice sheet is probably becoming thinner overall; although it is thickening in the west, it is thinning in the north. Joughin and Tulaczyk (2002), on the basis of analysis of ice-flow velocities derived from synthetic aperture radar, concluded that most of the Ross ice streams (ice streams on the east side of the Ross Ice Shelf) have a positive mass balance, whereas Rignot and others (in press) infer even larger negative mass balance for glaciers flowing northward into the Amundsen Sea, a trend suggested by Swithinbank and others (2003a,b, 2004). The mass balance of the East Antarctic part of the Antarctic ice sheet is unknown, but thought to be in near equilibrium. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), in subsequent recommendations by the Scientific Committee on Antarctic Research (SCAR) (1989, 1993), and by the National Science Foundation's (1990) Division of Polar Pro-grams. On the basis of these recommendations, the U.S. Geo-logical Survey (USGS) decided that the archive of early 1970s Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Ant-arctica and the subsequent repeat coverage made possible with Landsat and other satellite images provided an excellent means of documenting changes in the coastline of Antarctica (Ferrigno and Gould, 1987). The availability of this information provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica (Swithinbank, 1988; Williams and Ferrigno, 1988). The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) (and in some areas Landsat 7 Enhanced Thematic Mapper Plus (ETM+)), RADARSAT images, and other data where available, to compare changes during a 20- to 25- or 30-year time interval (or longer where data were available, as in the Antarctic Peninsula). The results of the analysis are being used to produce a digital database and a series of USGS Geologic Investigations Series Maps (I-2600) consisting of 23 maps at 1:1,000,000 scale and 1 map at 1:5,000,000 scale, in both paper and digital format (Williams and others, 1995; Williams and Ferrigno, 1998; Ferrigno and others, 2002) (available online at http://www.glaciers.er.usgs.gov).

IMAP↗
USGS2004

Coastal-change and glaciological map of the Eights Coast area, Antarctica, 1972-2001

Changes in the area and volume of polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level may severely impact the densely populated coastal regions on Earth. Melting of the West Antarctic part alone of the Antarctic ice sheet could cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m (Lythe and others, 2001) to 73 m (Williams and Hall, 1993). In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known for certain whether the ice sheet is growing or shrinking. In a review paper, Rignot and Thomas (2002) concluded that the West Antarctic part of the Antarctic ice sheet is probably becoming thinner overall; although the western part is thickening, the northern part is thinning. Joughin and Tulaczyk (2002), based on analysis of ice-flow velocities derived from synthetic aperture radar, concluded that most of the Ross ice streams (ice streams on the east side of the Ross Ice Shelf) have a positive mass balance. The mass balance of the East Antarctic is unknown, but thought to be in near equilibrium. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), in subsequent recommendations by the Scientific Committee on Antarctic Research (SCAR) (1989, 1993), and by the National Science Foundation's (1990) Division of Polar Programs. On the basis of these recommendations, the U.S. Geological Survey (USGS) decided that the archive of early 1970s Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Antarctica and the subsequent repeat coverage made possible with Landsat and other satellite images provided an excellent means of documenting changes in the coastline of Antarctica (Ferrigno and Gould, 1987). The availability of this information provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica (Swithinbank, 1988; Williams and Ferrigno, 1988). The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) (and in some areas Landsat 7 Enhanced Thematic Mapper Plus (ETM+)), RADARSAT images, and other data where available, to compare changes over a 20- to 25- or 30-year time interval (or longer where data were available, as in the Antarctic Peninsula). The results of the analysis are being used to produce a digital database and a series of USGS Geologic Investigations Series Maps consisting of 24 maps at 1:1,000,000 scale and 1 map at 1:5,000,000 scale, in both paper and digital format (Williams and others, 1995; Williams and Ferrigno, 1998; and Ferrigno and others, 2002).

IMAP↗
USGS2003

Coastal-change and glaciological map of the Bakutis Coast, Antarctica: 1972-2002

Changes in the area and volume of the polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level may severely impact the densely populated coastal regions on Earth. Loss of the West Antarctic part of the Antarctic ice sheet alone could cause a sea-level rise of approximately 6 m. The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m to 73 m. In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known whether the ice sheet is growing or shrinking. As a result, measurement of changes in the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), by the Scientific Committee on Antarctic Research (SCAR) (1989), and by the National Science Foundation's (1990) Division of Polar Programs. An archive of early 1970's Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Antarctica and the fact that the repeat coverage with satellite images provided an excellent means of documenting changes in the coastline of Antarctica provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica. The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) and RADARSAT images to compare changes over a 20- to 25- year time interval and to prepare a series of 24 1:1,000,000-scale and 1 1:5,000,000-scale U.S. Geological Survey Geologic Investigations Series Maps ('I-Maps') (Williams and others, 1995; Williams and Ferrigno, 1998; and Ferrigno and others, 2002) in both paper and digital format.

IMAP↗
USGS2003

Coastal-change and glaciological map of the Saunders Coast area, Antarctica: 1972-1997

Changes in the area and volume of polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level may severely impact the densely populated coastal regions on Earth. Melting of the West Antarctic part alone of the Antarctic ice sheet could cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m (Lythe and others, 2001) to 73 m (Williams and Hall, 1993). In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known for certain whether the ice sheet is growing or shrinking. In a review paper, Rignot and Thomas (2002) concluded that the West Antarctic part of the Antarctic ice sheet is probably becoming thinner overall; although the western part is thickening, the northern part is thinning. Joughin and Tulaczyk (2002), based on analysis of ice-flow velocities derived from synthetic aperture radar, concluded that most of the Ross ice streams (ice streams on the east side of the Ross Ice Shelf) have a positive mass balance. The mass balance of the East Antarctic is unknown, but thought to be in near equilibrium. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), in subsequent recommendations by the Scientific Committee on Antarctic Research (SCAR) (1989, 1993), and by the National Science Foundation?s (1990) Division of Polar Programs. On the basis of these recommendations, the U.S. Geological Survey (USGS) decided that the archive of early 1970s Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Antarctica and the subsequent repeat coverage made possible with Landsat and other satellite images provided an excellent means of documenting changes in the coastline of Antarctica (Ferrigno and Gould, 1987). The availability of this information provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica (Swithinbank, 1988; Williams and Ferrigno, 1988). The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) (and in some areas Landsat 7 Enhanced Thematic Mapper Plus (ETM+)), RADARSAT images, and other data where available, to compare changes over a 20- to 25- or 30-year time interval (or longer where data were available, as in the Antarctic Peninsula). The results of the analysis are being used to produce a digital database and a series of USGS Geologic Investigations Series Maps consisting of 24 maps at 1:1,000,000 scale and 1 map at 1:5,000,000 scale, in both paper and digital format (Williams and others, 1995; Williams and Ferrigno, 1998; and Ferrigno and others, 2002).

IMAP↗
USGS2007

Coastal-Change and Glaciological Map of the Northern Ross Ice Shelf Area, Antarctica: 1962-2004

Changes in the area and volume of polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level could severely impact the densely populated coastal regions on Earth. Melting of the West Antarctic part alone of the Antarctic ice sheet would cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m (Lythe and others, 2001) to 73 m (Williams and Hall, 1993). The mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is highly complex, responding differently to different conditions in each region (Vaughan, 2005). In a review paper, Rignot and Thomas (2002) concluded that the West Antarctic ice sheet is probably becoming thinner overall; although it is thickening in the west, it is thinning in the north. Thomas and others (2004), on the basis of aircraft and satellite laser altimetry surveys, believe the thinning may be accelerating. Joughin and Tulaczyk (2002), on the basis of analysis of ice-flow velocities derived from synthetic aperture radar, concluded that most of the Ross ice streams (ice streams on the east side of the Ross Ice Shelf) have a positive mass balance, whereas Rignot and others (2004) infer even larger negative mass balance for glaciers flowing northward into the Amundsen Sea, a trend suggested by Swithinbank and others (2003a,b; 2004). The mass balance of the East Antarctic ice sheet is thought by Davis and others (2005) to be strongly positive on the basis of the change in satellite altimetry measurements made between 1992 and 2003. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), in subsequent recommendations by the Scientific Committee on Antarctic Research (SCAR) (1989, 1993), and by the National Science Foundation?s (1990) Division of Polar Programs. On the basis of these recommendations, the U.S. Geological Survey (USGS) decided that the archive of early 1970s Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Antarctica and the subsequent repeat coverage made possible with Landsat and other satellite images provided an excellent means of documenting changes in the coastline of Antarctica (Ferrigno and Gould, 1987). The availability of this information provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica (Swithinbank, 1988; Williams and Ferrigno, 1988). The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) images (and in some areas Landsat 7 Enhanced Thematic Mapper Plus [ETM+] images), RADARSAT images, and other data where available, in order to compare changes that occurred during a 20- to 25- or 30-year time interval (or longer where data were available, as in the Antarctic Peninsula). The results of the analysis are being used to produce a digital database and a series of USGS Geologic Investigations Series Maps (I?2600) (Williams and others, 1995; Williams and Ferrigno, 1998; Ferrigno and others, 2002) (available online at http://www.glaciers.er.usgs.gov).

IMAP↗
USGS2010

Coastal-change and glaciological map of the Ross Island area, Antarctica

Reduction in the area and volume of Earth?s two polar ice sheets is intricately linked to changes in global climate and to the resulting rise in sea level. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council. On the basis of these recommendations, the U.S. Geological Survey used its archive of satellite images to document changes in the cryospheric coastline of Antarctica and analyze the glaciological features of the coastal regions. The Ross Island area map is bounded by long 141? E. and 175? E. and by lat 76? S. and 81? S. The map covers the part of southern Victoria Land that includes the northwestern Ross Ice Shelf, the McMurdo Ice Shelf, part of the polar plateau and Transantarctic Mountains, the McMurdo Dry Valleys, northernmost Shackleton Coast, Hillary Coast, the southern part of Scott Coast, and Ross Island. Little noticeable change has occurred in the ice fronts on the map, so the focus is on glaciological features. In the western part of the map area, the polar plateau of East Antarctica, once thought to be a featureless region, has subtle wavelike surface forms (megadunes) and flow traces of glaciers that originate far inland and extend to the coast or into the Ross Ice Shelf. There are numerous outlet glaciers. Glaciers drain into the McMurdo Dry Valleys, through the Transantarctic Mountains into the Ross Sea, or into the Ross Ice Shelf. Byrd Glacier is the largest. West of the Transantarctic Mountains are areas of blue ice, readily identifiable on Landsat images, that have been determined to be prime areas for finding meteorites. Three subglacial lakes have been identified in the map area. Because McMurdo Station, the main U.S. scientific research station in Antarctica, is located on Ross Island in the map area, many of these and other features in the area have been studied extensively. The paper version of this map is available for purchase from the USGS Store.

IMAP↗
USGS2013

Coastal-change and glaciological map of the Amery Ice Shelf area, Antarctica: 1961–2004

Reduction in the area and volume of Earth’s two polar ice sheets is intricately linked to changes in global climate and to the resulting rise in sea level. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council. On the basis of these recommendations, the U.S. Geological Survey used its archive of satellite images to document changes in the cryospheric coastline of Antarctica and analyze the glaciological features of the coastal regions. Amery Ice Shelf, lying between 67.5° and 75° East longitude and 68.5° and 73.2° South latitude, is the largest ice shelf in East Antarctica. The latest measurements of the area of the ice shelf range between 62,620 and 71,260 square kilometers. The ice shelf is fed primarily by Lambert, Mellor, and Fisher Glaciers; its thickness ranges from 3,000 meters in the center of the grounding line to less than 300 meters at the ice front. Lambert Glacier is considered to be the largest glacier in the world, and its drainage basin is more than 1 million square kilometers in area. It is possible to see some coastal change on the outlet glaciers along the coast, but most of the noticeable change occurs on the Amery Ice Shelf front.

IMAP↗
USGS1980

Maps showing composition of surficial sediments on the insular shelf of southwestern Puerto Rico

The limited availability of onshore sand deposits for use in construction appears to be a future major problem in Puerto Rico (U.S. Bureau of Mines, 1972; Committee on Puerto Rico and the Sea, 1974). Consequently, the mining of offshore sand deposits as supplemental sources of construction aggregate may becom e necessary. For this reason, the U.S. Geological Survey and the Department of Natural Resources of the Commonwealth of Puerto Rico have conducted investigations of potential offshore sand deposits on the Puerto Rico insular shelf. This report provides information on the composition of surficial sediments on the southwestern Puerto Rico shelf (fig. 1), an area that may be one of the more favorable potential sites for offshore sand resources. Water depths over most of the study area are less than 22 meters (m). The sea floor is composed of live and dead patch and fringing reefs, areas of rock exposures, and sedim ent-covered areas. The adjacent coastline includes prominent embaym ents and a conspicuous rock promontory (Cabo Rojo) connected by a tombolo to the mainland of Puerto Rico. The study area is in the belt of northeast trade winds. Waves approach the coast predominantly from the southeast, resulting in a predominantly westward littoral drift along the south coast (Grove and Trumbull, 1978). Local sand movement on the southern shelf is shown by an active sand wave field south of Bah1a Sucia in which the sand wave crests have migrated toward the southwest (Grove and Trumbull, 1978). The presence of the sand wave field suggests that large volumes of sand having potential for mining are locally present in the study area.

Puerto Rico↗
USGS1989

Vertical surface displacements along a part of the Newport-Inglewood zone of folds and faults, Los Angeles and Orange Counties, California

During the past half century, the onshore section of the Newport- Inglewood zone of folds and faults between the Dominguez oil field and Corona del Mar (fig. 1) has been repeatedly leveled to geodetic standards. These essentially fortuitous surveys are unrelated to either the tectonic framework or the urbanization of the Los Angeles basin, but were established instead because the Newport-Inglewood zone southward from the Long Beach area is roughly coincident with the coastline--and, hence, is roughly coincident with a naturally defined leveling route. Although these have been several relevelings athwart this zone north of the long Beach area, notably in the Baldwin Hills area (Castle and Yerkes, 1976), about 25 km to the northwest, the survey density, in both space and time, diminishes markedly northward. Thus, the results of the indicated relevelings along the Los Angeles-Orange County coast have permitted the relatively detailed appraisal of historic vertical surface movements described in this report. The Newport-Inglewood zone of folds and faults forms the surface expression of a major crustal boundary separating the Peninsular Ranges province on the east from the Continental Borderland province on the west (Castle and others, 1984, p. 8-9, pl. 1). Transcurrent fault movement along this boundary has produced not only continuing seismic activity, for which this zone is justly famous, but also folds and other structural features within the sedimentary veneer that have entrapped the petroleum deposits for which the Newport-Inglewood zone is even more famous. Although the northeast boundary of the exceptionally prolific Wilmington oil field is roughly coincident with the southeast edge of the Newport-Inglewood zone, we have deliberately excluded this area from consideration--in other than a peripheral way--simply because compaction-induced subsidence centering on the Wilmington field is viewed as a singularly spectacular example of this phenomenon and, hence, has been the subject of a series of detailed investigation (Harris and Harlow, 1947; Gilluly and Grant, 1949; Hudson, 1956; Miller, 1966; Poland and Davis, 1969; Allen and Mayuga, 1970; Castle and Yerkes, 1976).

California↗
USGS1999

Bathymetry of the Republic of the Marshall Islands and vicinity

The bathymetric map of the Republic of the Marshall Islands and vicinity is bounded by a window of latitude 3 to 17 degrees North, longitude 153 to 175 degrees East. The map was compiled from surveys conducted by the USGS, Korean Ocean Research and Development Institute, and published gridded data. In addition to national jurisdictions, island and atoll coastlines are indicated on the map.

Miscellaneous Field Studies Map↗
USGS2000

Cruise report RV Ocean Surveyor cruise O-1-00-GM the bathymetry and acoustic backscatter of the Pinnacles area, northern Gulf of Mexico May 23, through June 10, 2000 Venice, LA to Venice, LA

An extensive deep (~100 m) reef tract occurs on the Mississippi-Alabama outer continental shelf (OCS). The tract, known as "The Pinnacles", is apparently part of a sequence of drowned reef complexes along the "40-fathom" shelf edge of the northern Gulf of Mexico (Ludwick and Walton, 1957). It is critical to determine the accurate geomorphology of deep-reefs because of their importance as benthic habitats for fisheries. The Pinnacles were mapped by Ludwick and Walton (1957) using a single-beam echo sounder but the spatial extent and morphology were interpreted from a series of widely separated, poorly navigated bathymetric profiles. Other recent studies, supported by Minerals Management Service (MMS), used towed sidescan sonars and single-channel seismic-reflection profiling. None of the existing studies provide the quality of geomorphic data necessary for reasonable habitat studies. The fish faunas of shallow hermatypic reefs have been well studied, but those of deep ahermatypic reefs have relatively ignored. The ecology of deep ahermatypic reefs is fundamentally different from hermatipic reefs because autochthonous intracellular symbiotic zooxanthellae (the carbon source for hermatypic corals) do not form the base of the trophic web. Instead, exogenous plankton, transported to the reef by currents, serves as the primary carbon source. Deep OCS reefs also lie below the practical working depths for SCUBA; consequently, remote investigations from a ship or in situ investigations using submersibles or ROVs are required. Community structure and trophodynamics of demersal fishes of the Pinnacles are presently the focus of USGS reseach. A goal of the research is to answer questions concerning the relataive roles played by geomorphology and surficial geology in the interaction with and control of biological differentiation. OCS reefs are important because we now know that such areas are important coral reef fish havens, key spawning 2 sites, and a critical early larval and juvenile habitats for economically important sport/food fishes. Also, deep-reef ecosystems as well as the fish populations they sustain are impacted by intensive oil-field development. It is now known that deep OCS reefs function as a key source of re-population (via seasonal and ontogenetic migration) of already heavily impacted inshore reefs. A reflection of this realization is the recent closure by the Gulf States Fisheries Management Council of a 600 mi 2 area of the Florida Middle Grounds (another unmapped major "40-fathom" OCS reef complex) to commercial fishing to preserve grouper spawning aggregations. It is known that the Pinnacles reefs support a lush fauna of ahermatypic hard corals, soft corals, black corals, sessile crinoids and sponges—together forming a living habitat for a well-developed fish fauna. The fish fauna comprises typical Caribbean reef fishes and Carolinian shelf fishes, plus epipelagic fishes, and a few deep-sea fishes. The base of the megafaunal invertebrate food web is plankton, borne by essentially continuous semi-laminar currents flowing predominantly out of the SW, up, along and across the shelf edge. These currents are intercepted by pinnacles reefs, which lie roughly in two linear tracts, parallel to the coastline (see fig. 1 in report). USGS research initiated in 1997 (Sulak et al., in progress) has demonstrated that the Pinnacles reef fish fauna is dominated by planktivorous fishes. Ongoing food habits, trophic web and stable isotope analyses by the USGS are reinforcing a basic picture of deep OCS reefs as ecosystems based on exogenous current-borne plankton. Long-term current meter deployments have demonstrated that the >3 m, <16m relief of the Pinnacles reefs disrupts the prevailing currents, inducing local complexity (F. Kelly, Texas A&M Univ., pers. comm.) favorable to plankton and planktivores. Geodetically accurate bathymetry maps, coregistered with calibrated acoustic backscatter maps, are critical to delineate benthic biotopes, and are essential to correlate biological community differentiation with the physical environment. Previous mapping of the Pinnacles area using the TAMU towed single-beam sidescan system (Anonymous., 1999) employed technology with inherent deficiencies in backscatter calibration, bathymetric precision, and geo-referencing. The resulting bathymetric interpretations of TAMU data are further degraded by ship-track-parallel artifacts that obliterate geomorphology rendering them inadequate to provide high-resolution mapping of individual target reefs (typical maximum relief 15 m, diameter 200-500 m). The sidescan-sonar surveys of the area (Laswell et al., 1990) suffer many of the same deficiencies as the TAMU data so they add no quantitative and little qualitative information about the geomorphology and surficial geology.

Gulf of Mexico, the Pinnacles area↗
USGS2002

Physical data of soil profiles formed on late Quaternary marine terraces near Santa Cruz, California

The marine terraces in and around Santa Cruz, California, represent a set of well-preserved terraces formed as a product of geology, sea level, and climate. A marine terrace begins as a wave cut platform. Eustatic sea level changes, seacliff erosion, and tectonic uplift work together to generate marine terraces. "When a wave-cut platform is raised (due to tectonic activity) above sea level and cliffed by wave action it becomes a marine terrace" (Bradley, 1957, p. 424). During glacial periods, eustatic sea level is estimated to have dropped by 150 meters (Fairbanks, 1989). Cliff retreat measured from aerial photographs between 1930 and 1980 vary from 0.0 to 0.2 m yr–1 (Best and Griggs, 1991). Estimates of uplift rates along the Santa Cruz coastline vary from 0.10 to 0.48 m kyr–1 (Bradley and Griggs, 1976; Weber and others, 1999). Uplift mechanisms include coseismic uplift associated both with a reverse component of slip on the steeply SW dipping Loma Prieta fault in the restraining bend of the San Andreas Fault and a small component of reverse slip on the steeply SE dipping San Gregorio fault (Anderson and Menking 1994). Previous work studying physical properties on these terraces include Pinney and others (in press) and Aniku (1986) and Bowman and Estrada (1980). Sedimentary deposits of the marine terraces are a mixture of terrestrial and marine sediments but generally consist of a sheet of marine deposits overlying the old platform and a wedge of nonmarine deposits banked against the old sea cliff (Bradley, 1957). Bedrock underlying the terraces in the Santa Cruz area is generally either Santa Margarita Sandstone or Santa Cruz Mudstone. The Santa Margarita Sandstone represents an upper Miocene, transgressive, tidally dominated marine-shelf deposit with crossbedded sets of sand and gravel and horizontally stratified and bioturbated invertebrate-fossils beds (Phillips, 1990). The siliceous Santa Cruz Mudstone, of late Miocene age, conformably overlies the Santa Margarita Sandstone. The Santa Cruz Mudstone is a thin to medium-bedded siliceous mudstone with nonsiliceous mudstone and siltstone and minor amounts of sandstone. The siliceous nature implies organic deposition in a quiescent, deep-water environment. Bedrock is mantled by 1–4 meters of medium to coarse-grained regressive beach sediment and fluvial deposits from the Ben Lomond Mountains. Terrace age increases with elevation above sea level, and weathering of primary minerals increases with age. The suite of soils formed on the terraces is referred to as a soil chronosequence. Soil chronosequences, important tools in characterizing natural weathering rates, are defined as a group of soils that differ in age and therefore in duration of weathering but have similar climatic conditions, vegetation, geomorphic position, and parent material (Jenny, 1941; Birkland, 1999). Soils are frequently useful indicators of geomorphic age (Muhs, 1982; Switzer and others, 1988) and are a function of pedogenic and/or eolian processes. Some aspects of soil development can be episodic but when viewed on large time scales can be perceived as continuous (Switzer and others, 1988). The age of the soil may be constrained by the age of the deposit, since soil formation generally commences when deposition has ceased (Birkland, 1999). Dating of the terraces provides an unprecedented opportunity to study weathering and soil-formation rates (Perg and others, 2001; Hanks and others, 1984; Bradley and Griggs, 1976; Bradley and Addicott, 1968; Bradley, 1956). Ages of the terraces recently dated by cosmogenic radionuclide are, starting with the youngest, 65, 92, 137, 139, and 226 k.y. (Perg and others, 2001). However, these ages are much younger than recent radiometric dates on mollusk shells (Muhs, U.S. Geological Survey, personal communication, 2002; Bradley and Addicott, 1968). For this study, soils were sampled on five terraces. Terrace one in the Lighthouse Field along Westcliff in Santa Cruz was the last site selected, and this report contains minimal data on this terrace. Sites on the second, third, and fourth terraces are located in Wilder Ranch, Santa Cruz, California. Site five is on private property north of Wilder Ranch. Careful consideration was taken in selecting field sites, choosing locations in a topographically flat area to avoid effects of erosion, and trying to keep parent material similar. This report contains physical properties of the soil profiles on four of the five marine terraces near Santa Cruz, California, excluding the youngest terrace in all tables except 6 and 7. Data includes field descriptions, bulk density, grain size analyses, weight percent magnetic fraction, and the soil development index. Soil properties are important when trying to understand the chemistry of a given profile or when comparing profiles. Grain size constrains the movement of water in a profile, thus controlling movement of chemicals and weathering rates. Bulk density is a useful property to calculate chemical inventory. Quantifying the magnetic fraction aids in understanding the Fe inventory for these soils. The soil development index is a semi-quantitative way to define the degree of development of a soil profile. This is a useful way to compare development of profiles for this chronosequence or compare the Santa Cruz terraces to a suit of other terraces or another chronosequence.

California↗
USGS2003

Cruise summary for P-1-02-SC: acoustic imaging of natural oil and gas seeps and measurement of dissolved methane concentration in coastal waters near Pt. Conception, California

Water-column acoustic anomalies and methane concentrations were documented in coastal waters surrounding Pt. Conception, California, in March 2002. The purpose of this survey, supported by the Minerals Management Service, was to locate active oil and gas seeps in the area as a background for further studies to determine hydrocarbon flux, mainly oil, into the environment. Objectives in reaching this goal are to (1) document the locations and geochemically fingerprint natural seeps within the offshore southern Santa Maria Basin; (2) geochemically fingerprint coastal tar residues and potential sources, both onshore and offshore, in this region; (3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; (4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; (5) attempt to predict transport pathways of oil from seep sources to the coastline and; (6) interpret the petroleum system history for the natural seeps. This survey, addressing objective 1, focused on the area from offshore Surf Beach to the north and Gaviota to the south in water depths ranging from 20 to 500m. In addition, nine stations were sampled outside this area to provide a regional context. Water-column methane concentrations were measured in water samples collected from the R/V Point Sur with Niskin bottles from various depths. A total of 724 water samples from 94 stations were collected.

California↗
USGS2004

The Catfish Lake Scarp, Allyn, Washington: Preliminary field data and implications for earthquake hazards posed by the Tacoma fault

The Tacoma fault bounds gravity and aeromagnetic anomalies for 50 km across central Puget lowland from Tacoma to western Kitsap County. Tomography implies at least 6 km of post-Eocene uplift to the north of the fault relative to basinal sedimentary rocks to the south. Coastlines north of the Tacoma fault rose about 1100 years ago during a large earthquake. Abrupt uplift up to several meters caused tidal flats at Lynch Cove, North Bay, and Burley Lagoon to turn into forested wetlands and freshwater marshes. South of the fault at Wollochet Bay, Douglas-fir forests sank into the intertidal zone and changed into saltmarsh. Liquefaction features found beneath the marsh at Burley Lagoon point to strong ground shaking at the time of uplift. Recent lidar maps of the area southwest of Allyn, Washington revealed a 4 km long scarp, or two closely spaced en-echelon scarps, which correspond closely to the Tacoma fault gravity and aeromagnetic anomalies. The scarp, named the Catfish Lake scarp, is north-side-up, trends east-west, and clearly displace striae left by a Vashon-age glacier. A trench across the scarp exposed evidence for postglacial folding and reverse slip. No organic material for radiocarbon dating was recovered from the trench. However, relationships in the trench suggest that the folding and faulting is postglacial in age.

Washington↗
USGS2000

The Monterey Submarine Canyon, California, CTD Data Report Part C: The R/V Robert Gordon Sproul Cruise S-1-94-MB, Aug. 17 - 22, 1994

In August 1993, a program was begun to study the mechanisms that govern the circulation within and the transport of sediment and water through Monterey Submarine Canyon. This is a very large, deep submarine canyon off central California that incises the continental margin from the outer slope to close to the coastline. A key component of the study was to document the interactions between circulation patterns above the canyon, within the canyon, and past the mouth of the canyon. The first part of this program entailed deploying a set of six moorings to measure current, temperature, salinity, and water clarity for one year within Monterey Canyon. The information from the moorings can be found in the U. S. Geological Survey Open File Report 95-838. In the second part of this program, which is the subject of this report, four cruises were conducted during August 1993 to November 1994 within Monterey Bay and along the Monterey Canyon to collect salinity, temperature, and water clarity data with depth (CTD data). The data from each of the four cruises are presented in detail in four separate reports. This report describes and depicts the data collected from the RN Robert Gordon Sproul cruise S-1-94-MB (labeled in our reports as S-1-94-MB).

California↗
USGS2002

Preliminary geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California

This report presents a new geologic digital map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. This preliminary map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Santa Barbara and Goleta 7.5' quadrangles. A planned second version will extend the mapping westward into the adjoining Dos Pueblos Canyon quadrangle and eastward into the Carpinteria quadrangle. The mapping presented here results from the collaborative efforts of geologists with the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) (Minor, Kellogg, Stanley, Stone, and Powell) and the tectonic geomorphology research group at the University of California at Santa Barbara (Gurrola and Selting). C.L. Powell, II, performed all new fossil identifications and interpretations reported herein. T.R. Brandt designed and edited the GIS database,performed GIS database integration and created the digital cartography for the map layout. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along a west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The coastal plain region, which extends from the Santa Ynez Mountains on the north to the Santa Barbara Channel on the south, is underlain by numerous active and potentially active folds and partly buried thrust faults of the Santa Barbara fold and fault belt. Strong earthquakes that occurred in the region in 1925 (6.8 magnitude) and 1978 (5.1 magnitude) are evidence that such structures pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. Also, young landslide deposits along the steep lower flank of the Santa Ynez Mountains indicate the potential for continued slope failures and mass movements that may threaten urbanized parts of the coastal plain. Deformed sedimentary rocks in the subsurface of the coastal plain and the adjacent Santa Barbara Channel contain deposits of oil and gas, some of which are currently being extracted. Shallow, localized sedimentary aquifers underlying the coastal plain provide limited amounts of water for the urban areas, but the quality of some of this groundwater is compromised by coastal salt-water contamination. The present map compilation provides a set of uniform geologic digital coverages that can be used for analysis and prediction of these and other geologic hazards and resources in the coastal plain region. In the map area the oldest stratigraphic units consist of resistant Eocene to Oligocene marine and terrestrial sedimentary rocks that form a mostly southward-dipping and laterally continuous sequence along the south flank of the Santa Ynez Mountains. Less resistant, but more variably deformed, Miocene, Pliocene, and Pleistocene marine sedimentary rocks and deposits are exposed in the lower Santa Ynez foothills and in the coastal hills and sea cliffs farther south. Pleistocene and Holocene surficial alluvial, colluvial, estuarine, and marine-terrace deposits directly underlie much of the low-lying coastal plain area, and similar-aged alluvial and landslide deposits locally mantle the lower flanks of the Santa Ynez Mountains. Structurally, the Santa Barbara coastal plain area is dominated by the Santa Barbara fold and fault belt, an east-west-trending zone of Quaternary, partly active folds and blind and exposed reverse and thrust faults. The dominant trend of individual structures within the belt is west-northwest -- slightly oblique to the overall trend of the fold and fault belt. A conspicuous exception, however, is the More Ranch fault system, which strikes east-northeast across the fold and f

Open-File Report↗
USGS2004

Historic topographic sheets to satellite imagery&mdash;A methodology for evaluating coastal change in Florida's Big Bend tidal marsh

This open-file report details the methodology used to rectify, digitize, and mosaic nineteen 19th century topographic sheets on the marsh-dominated Big Bend Gulf coast of Florida. Historic charts of tidal marshes in Florida's Big Bend were prepared in a digital grid-based format for comparison with modern features derived from 1995 satellite imagery. The chart-by-chart rectification process produced a map accuracy of &plusmn; 8 m. An effort was made to evaluate secondary map features, such as tree islands, but changes during the intervening years exceed standard surveying errors and rendered the analysis ineffective. A map, at 1:300,000 comparing historic and modern features, is provided to illustrate major changes along the coastline. Shoreline erosion is exceeded by the inland migration of the intertidal zone onto adjoining coastal forest lands. While statements of mapping accuracy are provided in the text, graphic representation of changes in the intertidal zone may be inexact at any given location. Thus caution is advised for site-specific applications. Maps and digital files provided should be used to visualize overall trends and regional anomalies, and not used to critically assess features at a particular location. Final product includes mosaic of historic coastal features and comparison to modern features.

Florida↗
USGS2003

Using the Landsat 7 enhanced thematic mapper tasseled cap transformation to extract shoreline

A semiautomated method for objectively interpreting and extracting the land-water interface has been devised and used successfully to generate multiple shoreline data for the test States of Louisiana and Delaware. The method is based on the application of tasseled cap transformation coefficients derived by the EROS Data Center for Landsat 7 Enhanced Thematic Mapper Data, and is used in conjunction with ERDAS Imagine software. Shoreline data obtained using this method are cost effective compared with conventional mapping methods for State, regional, and national coastline applications. Attempts to attribute vector shoreline data with orthometric elevation values derived from tide observation stations, however, proved unsuccessful.

Open-File Report↗