SEARCH · Search USGS

Results for “Coasts”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

USGS1998

Upper Paleocene and lowermost Eocene angiosperm pollen biostratigraphy of the eastern Gulf Coast and Virginia

Strata comprising most of the upper Paleocene in eastern North America are divided into two new pollen zones, the Carya and Platycarya platycaryoides Interval Zones. Pollen data have proven to be important for correlations between Alabama-western Georgia and eastern Mississippi and between the eastern Gulf Coast and Virginia. Migration of tropical plant taxa from the Caribbean to the Gulf Coast began at least 4 m.y. before the end of the Paleocene. The Terminal Paleocene Extinction Event, accompanied by a distinct pulse of plant immigration from Europe, began several hundred thousand years before the end of the Paleocene.

Micropaleontology↗

USGS2001

Black bear (Ursus americanus Pallas) feeding damage across timber harvest edges in northern California coast redwood (Sequoia sempervirens[D. Don] Endl.) forests, USA

Feeding damage to trees by black bears (Ursus americanus Pallas) was recorded in proximity to timber harvest edges in harvested and old-growth stands of coast redwood (Sequoia sempervirens [D. Don] Endl.) in northern California, USA. Bears exhibited distinct preference in their feeding patterns related to stand structure and composition and to distance from the timber-harvest edge. Most damage was recorded within regenerating stands. Regression analysis indicated that density of damaged trees was negatively correlated with distance from timber harvest edges within old-growth stands. A significant negative correlation was also found between the density of trees damaged by bears and habitat diversity (H') as measured by the Shannon diversity index. In addition, bears exhibited preference for pole-size trees (dbh = 10-50 cm) over all other size classes, and coast redwood over other species. In general, damage by bears appeared to act as a natural thinning agent in even-aged stands. No damage was recorded in old-growth stands except in close proximity to the timber-harvest edge where subcanopy recruitment was high.

California↗

USGS2004

Morphology and sedimentation on open-coast intertidal flats of the Changjiang Delta, China

On many intertidal flats, lateral aggradation and reworking by large tidal channels is the dominant sedimentary process. On the open-coast intertidal flats of the Changjiang Delta large laterally migrating tidal channels are absent. Instead, numerous shallow tidal creeks cut across the intertidal flats. On these flats, vertical rather than lateral migration dominates sedimentation. Observations over semidiurnal tidal cycles show that both flood and ebb tides have the potential to deposit their own mud-sand couplets, but four couplets per day are rarely preserved. Reworking by tidal currents and/or weak waves results in loss of tidal couplets or amalgamation of two or more thin couplets into a single thick couplet. Measurements of preserved couplets show that they can represent a single flooding or ebbing event (half day) to a period of several neap-spring cycles. Diastems within amalgamated couplets are generally not distinguishable. The key agent for reworking open-coast intertidal flat deposits is not tidal creek migration but seasonal storm waves. Seasonal storm deposits consist of a basal scour and sand-dominant laminae with mud pebbles, grading upward to mud-dominated layers of fair-weather deposits. Sand-dominated layers are also reworked.

Conference Paper↗

USGS2006

Association of the 1886 Charleston, South Carolina, earthquake and seismicity near Summervile with a 12º bend in the East Coast fault system and triple-fault junctions

Seismic-reflection data were integrated with other geophysical, geologic, and seismicity data to better determine the location and nature of buried faults in the Charleston, South Carolina, region. Our results indicate that the 1886 Charleston, South Carolina, earthquake and seismicity near Summerville are related to local stresses caused by a 12?? bend in the East Coast fault system (ECFS) and two triple-fault junctions. One triple junction is formed by the intersection of the northwest-trending Ashley River fault with the two segments of the ECFS north and south of the bend. The other triple junction is formed by the intersection of the northeast-trending Summerville fault and a newly discovered northwest-trending Berkeley fault with the ECFS about 10 km north of the bend. The Summerville fault is a northwest-dipping border fault of the Triassic-age Jedburg basin that is undergoing reverse-style reactivation. This reverse-style reactivation is unusual because the Summerville fault parallels the regional stress field axis, suggesting that the reactivation is from stresses applied by dextral motion on the ECFS. The southwest-dip and reverse-type motion of the Berkeley fault are interpreted from seismicity data and a seismic-reflection profile in the western part of the study area. Our results also indicate that the East Coast fault system is a Paleozoic basement fault and that its reactivation since early Mesozoic time has fractured through the overlying allochthonous terranes.

Southeastern Geology↗

USGS2012

Overpressure and hydrocarbon accumulations in Tertiary strata, Gulf Coast of Louisiana

Many oil and gas reservoirs in Tertiary strata of southern Louisiana are located close to the interface between a sand-rich, normally pressured sequence and an underlying sand-poor, overpressured sequence. This association, recognized for many years by Gulf Coast explorationists, is revisited here because of its relevance to an assessment of undiscovered oil and gas potential in the Gulf Coast of Louisiana. The transition from normally pressured to highly overpressured sediments is documented by converting mud weights to pressure, plotting all pressure data from an individual field as a function of depth, and selecting a top and base of the pressure transition zone. Vertical extents of pressure transition zones in 34 fields across southern onshore Louisiana range from 300 to 9000 ft and are greatest in younger strata and in the larger fields. Display of pressure transition zones on geologic cross sections illustrates the relative independence of the depth of the pressure transition zone and geologic age. Comparison of the depth distribution of pressure transition zones with production intervals confirms previous findings that production intervals generally overlap the pressure transition zone in depth and that the median production depth lies above the base of the pressure transition zone in most fields. However, in 11 of 55 fields with deep drilling, substantial amounts of oil and gas have been produced from depths deeper than 2000 ft below the base of the pressure transition zone. Mud-weight data in 7 fields show that "local" pressure gradients range from 0.91 to 1.26 psi/ft below the base of the pressure transition zone. Pressure gradients are higher and computed effective stress gradients are negative in younger strata in coastal areas, indicating that a greater potential for fluid and sediment movement exists there than in older Tertiary strata.

Louisiana↗

USGS2013

User's guide and metadata for WestuRe: U.S. Pacific Coast estuary/watershed data and R tools

Overview There are about 350 estuaries along the U.S. Pacific Coast (U.S. Fish andWildlife 2011). Basic descriptive data for these estuaries, such as their size and watershed area, are important for coastal-scale research and conservation planning. However, this information is spread among many sources, making it difficult to find and standardize. The goal of the WestuRe Project is to provide a framework to: (1) make general descriptive data for estuaries and their watersheds more accessible, and (2) provide tools to make analyzing and visualizing these data easier. The WestuRe download includes data describing U.S. Pacific Coast estuaries and their corresponding watersheds from northern Washington (including the region located along the Strait of Juan de Fuca that goes from Port Townsend to Cape Flattery, 48.383°N) to southern California (Tijuana Estuary, 32.557°N), excluding Puget Sound proper and coastal islands (Fig. 1). The WestuRe data currently include shapefiles of estuary and watershed polygons as well as CSV files summarizing geomorphological and climate data (Fig. 2, Section 2). The WestuRe tools help users extract and view relevant data using the statistical program R and Google Earth (Fig. 3, Section 3). Potential applications of the data include: Describing and comparing estuaries and watersheds at the landscape scale Identifying relationships between estuary/watershed variables Incorporating estuary/watershed attributes in models to predict species and habitat distributions Classifying estuaries according to morphology, climate, and habitat (Lee and Brown 2009)

California, Oregon, Washington↗

USGS1993

Temporal and spatial variation in habitat characteristics of Tilefish (Lopholatilus Chamaeleonticeps) off the east coast of Florida

The tilefish, Lopholatilus chamaeleonticeps , constructs burrows in carbonate sediments off the central east coast of Florida at similar temperatures (8.6-15.4°C) and in similar sediment textures (high proportion of silts and clays) to conspecifics in the Mid-Atlantic Bight. The depths at which we observed tile fish off Florida (150-290 m), based on submersible observations and sidescan sonar operations during 1983 and 1984, were similar to those recorded in 1975-1977 (137-266 m) before the inception of the directed fishery. Both are similar to the range observed in the Mid-Atlantic Bight although tilefish there can be found at shallower and slightly deeper depths (80-305 m). The largest burrows off Florida (1.5-m diameter) were smaller than those observed in the Mid-Atlantic Bight (up to 5 m). The behavior of tile fish around the burrow and the invertebrates and fishes co-inhabiting the burrows off Florida are nearly identical to those in the Mid-Atlantic Bight. Despite the relatively narrow annual temperature range observed off Florida, abrupt changes in temperatures (+6°C) occurred over a 48-h period based on thermograph records. Our observations, and those of others from several areas along the U.S. east coast, suggest that this species probably constructs burrows throughout its geographic range, and that temperature and sediment composition largely determine its distribution. Exclusion experiments off Florida, along with prior removal experiments in the Mid-Atlantic Bight, indicate that tilefish construct and maintain the burrows.

Florida↗

USGS1987

Genetic variation in chinook, Oncorhynchus tshawytscha , and coho, O. Kisutch</i?, salmon from the north coast of Washington

We used starch-gel electrophoresis to genetically characterize the populations of chinook salmon, Oncorhynchus tshawytscha, and coho salmon, O. kisutch, in the major drainages of the north coast of Washington (the Quillayute, Uoh, Queets, and Quinault Rivers). Of 55 loci examined for electrophoretically detectable variation. 6 were polymorphic (frequency of the common allele was less than 0.95) in chinook salmon and 3 in coho salmon. Statistical tests of interdrainage and intradrainage variation for coho salmon were tenuous because most of the fish examined were from a single year class so that we could not account for variation among year classes. Nevertheless, these tests suggested that distinct stocks ofcoho salmon exist within drainages. and that variation was not significantly greater among drainages than within drainages. Interdrainage variation for wild chinook salmon was not significant. The data suggested that summer chinook salmon were electrophoretically different from fall chinook salmon, and the hatchery populations of chinook salmon were distinct from wild fish. A hatchery population developed primarily from north coast fish was electrophoretically more similar to wild chinook salmon than were the others.

Washington↗

USGS2013

Ocean climate indicators: A monitoring inventory and plan for tracking climate change in the north-central California coast and ocean region

The impacts of climate change, defined as increasing atmospheric and oceanic carbon dioxide and associated increases in average global temperature and oceanic acidity, have been observed both globally and on regional scales, such as in the North-central California coast and ocean, a region that extends from Point Arena to Point Año Nuevo and includes the Pacific coastline of the San Francisco Bay Area. Because of the high economic and ecological value of the region’s marine environment, the Gulf of the Farallones National Marine Sanctuary (GFNMS) and other agencies and organizations have recognized the need to evaluate and plan for climate change impacts. Climate change indicators can be developed on global, regional, and site-specific spatial scales, and they provide information about the presence and potential impacts of climate change. While indicators exist for the nation and for the state of California as a whole, no system of ocean climate indicators exist that specifically consider the unique characteristics of the California coast and ocean region. To that end, GFNMS collaborated with over 50 regional, federal, and state natural resource managers, research scientists, and other partners to develop a set of 2 ocean climate indicators specific to this region. A smaller working group of 13 regional partners developed monitoring goals, objectives, strategies, and activities for the indicators and recommended selected species for biological indicators, resulting in the Ocean Climate Indicators Monitoring Inventory and Plan. The working group considered current knowledge of ongoing monitoring, feasibility of monitoring, costs, and logistics in selecting monitoring activities and selected species.

Report↗

USGS1975

K-Ar ages of plutonic rocks in the Lassiter Coast area, Antarctica

Numerous middle Cretaceous stocks and small batholiths intruded Middle and Upper Jurassic sedimentary and volcanic rocks in the Lassiter Coast area of the southern Antarctic Peninsula. To establish the age of the quartz diorite and granodiorite plutonic events, five plutons were dated by the K-Ar method. The results indicate a timespan of about 20 m.y. for the emplacement of the plutons and a minimum age of 120 m.y. for the deformation of the sedimentary (Latady Formation) and volcanic rocks. Three of the more silicic plutons have concordant biotite and hornblende ages of 100 and 106 m.y.; two discordant ages of about 118 m.y. were obtained on the more mafic plutons. Petrographically, chemically, and geochronologically, the plutons of the southern to central Lassiter Coast are similar to the calc-alkaline suite of igneous rocks of the Andes of Patagonia, the Antarctic Peninsula, and eastern Ellsworth Land.

Journal of Research of the U.S. Geological Survey↗

USGS1985

Water quality and chemical evolution of ground water within the north coast limestone aquifers of Puerto Rico

Waters within the north coastal limestone aquifers are suitable for public supply, industrial and agricultural uses. For the artesian aquifer and the updip parts of the water table aquifer, calcium and bicarbonate are the dominant ionic species with total dissolved solids and chloride concentrations below 500 and 250 mg/L, respectively. In coastal areas of the water table aquifer, where a freshwater-saltwater mixing zone occurs, the calcium bicarbonate facie grade to a sodium-chloride facie. Within this zone, concentrations of total dissolved solids and chloride are greater than 250 and 500 mg/L respectively, affecting the suitability of the water for some uses. Geochemical models were constructed to determine the physical and chemical reasons for the prevailing water quality patterns of the north coast limestone aquifers . Models indicate that calcite and carbon dioxide dissolution, precipitation or degassing are the primary processes. The mixing of recharge water or saltwater with aquifer waters is an important feature within the water table aquifer. The models provide further evidence that support the circulation of groundwater within the north coast limestone.

Conference Paper↗

USGS2007

Viability criteria for steelhead of the south-central and southern California coast

Recovery planning for threatened and endangered steelhead requires measurable, objective criteria for determining an acceptably low risk of extinction. Here we propose viability criteria for two levels of biological organization: individual populations, and groups of populations within the SouthCentral/Southern California Coast Steelhead Recovery Planning Domain. For populations, we adapt criteria commonly used by the IUCN (The World Conservation Union) for identifying at-risk species. For groups of populations we implement a diversity-based “representation and redundancy rule,” in which diversity includes both life-history diversity and biogeographic groupings of populations. The resulting criteria have the potential for straightforward assessment of the risks posed by evolutionary, demographic, environmental, and catastrophic factors; and are designed to use data that are readily collected. However, our prescriptive approach led to one criterion whose threshold could not yet be specified due to inadequate data, and others in which the simplicity of the criteria may render them inefficient for populations with stable run sizes or stable life-history polymorphisms. Both of these problems could likely be solved by directed programs of research and monitoring aimed at developing more efficient (but equally risk-averse) “performance-based criteria.” Of particular utility would be data on the natural fluctuations of populations, research into the stabilizing influence of life-history polymorphisms, and research on the implications of drought, wildfires, and fluvial sediment regimes. Research on estuarine habitat could also yield useful information on the generality and reliability of its role as nursery habitat. Currently, risk assessment at the population level is not possible due to data deficiency, highlighting the need to implement a comprehensive effort to monitor run sizes, anadromous fractions, spawner densities and perhaps marine survival. Assessment at the group level indicates a priority for securing inland populations in the southern Coast Ranges and Transverse Ranges, and a need to maintain not just the fluvial-anadromous life-history form, but also lagoon-anadromous and freshwater-resident forms in each population.

Report↗

USGS2016

Terrestrial vegetation monitoring protocol for the Mediterranean Coast Network—Cabrillo National Monument, Channel Islands National Park, and Santa Monica Mountains National Recreation Area: Standard Operating Procedures, Version 1.0

These Standard Operating Procedures are one part of a two-part protocol for monitoring terrestrial vegetation in the Mediterranean Coast Network. The second part of the protocol is the narrative: Tiszler, J., D. Rodriguez, K. Lombardo, T. Sagar, L. Aguilar, L. Lee, T. Handley, K. McEachern, L. Starcevich, M. Witter, T. Philippi, and S. Ostermann-Kelm. 2016. Terrestrial vegetation monitoring protocol for the Mediterranean Coast Network—Cabrillo National Monument, Channel Islands National Park, and Santa Monica Mountains National Recreation Area: Narrative, version 1.0. Natural Resource Report NPS/MEDN/NRR—2016/1296. National Park Service, Fort Collins, Colorado. National parks in the Mediterranean Inventory and Monitoring Network: Cabrillo National Monument (CABR) Channel Islands National Park (CHIS) Santa Monica Mountains National Recreation Area (SAMO)

Natural Resource Report↗

USGS2008

Preliminary results of the U.S. Nuclear Regulatory Commission collaborative research program to assess tsunami hazard for nuclear power plants on the Atlantic and gulf coasts

In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and other key researchers for the purpose of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. The initial phase of this work consisted principally of collection, interpretation, and analysis of available offshore data and information. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts over the long time periods of interest to the US NRC is a key difference between this program and most other tsunami hazard assessment programs. Although only a few years old, this program is already producing results that both support current US NRC activities and look toward the long-term goal of probabilistic tsunami hazard assessment. This paper provides a summary of results from several areas of current research. An overview of the broader US NRC research program is provided in a companion paper in this conference.

Conference Paper↗

USGS2017

Overview of the U.S. Nuclear Regulatory Commission collaborative research program to assess tsunami hazard for nuclear power plants on the Atlantic and Gulf Coasts

In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) with a goal of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts is a key difference between this program and most other tsunami hazard assessment programs. The initial phase of this work consisted of collection, interpretation, and analysis of available offshore data, with significant effort focused on characterizing offshore near-field landslides and analyzing their tsunamigenic potential and properties. In the next phase of research, additional field investigations will be conducted in key locations of interest and additional analysis will be undertaken. Simultaneously, the MOST tsunami generation and propagation model used by NOAA will first be enhanced to include landslide-based initiation mechanisms and then will be used to investigate the impact of the tsunamigenic sources identified and characterized by the USGS. The potential for probabilistic tsunami hazard assessment will also be explore in the final phases of the program.

Conference Paper↗

USGS1991

Franciscan Complex, Coast Range ophiolite and Great Valley sequence: Pacheco Pass to Del Puerto Canyon, California

This field trip covers part of the Diablo Range and adjacent San Joaquin Valley of central California (Fig. 1 ). The core of the range is made up of rocks of the Franciscan Complex, flanked by Coast Range ophiolite (CRO) and Great Valley sequence (GVS). The Franciscan Complex in this area consists of deformed and metamorphosed sedimentary and volcanic rocks containing fossils of Late Jurassic to Late Cretaceous age. These rocks are believed to represent an accretionary wedge that was subducted to depths of 12-20 mi (20-30 km). The Middle to Late Jurassic CRO represents a slab of oceanic upper mantle and crust that was trapped between the Sierran magmatic arc and the Franciscan trench. The Upper Jurassic to Upper Cretaceous GVS is a thick accumulation of mudstone, sandstone, and con- glomerate that was deposited on the ophiolite in a forearc-basin setting. The objectives of this field trip are to examine good exposures of these three major units in order to better understand their sedimentary, igneous, and metamorphic histories, to examine some of the major faults bounding the units, and to gain an understanding of the tectonic history of this portion of the Coast Ranges.

Book chapter↗

USGS2018

Monitoring wadeable stream habitat conditions in Southeast Coast Network parks: Protocol narrative

The Southeast Coast Network (SECN) has initiated a monitoring effort to assess habitat conditions in wadeable streams at national parks, recreation areas, battlefields, and monuments in Alabama, Georgia, and South Carolina. This monitoring effort includes Chattahoochee River National Recreation Area, Kennesaw Mountain National Battlefield Park, Congaree National Park, Horseshoe Bend National Military Park, and Ocmulgee National Monument. Stream habitat monitoring was implemented in 2016, and focuses specifically on providing relevant data to assess the physical condition of Piedmont and upper Coastal Plain streams with respect to aquatic and riparian habitats and how these habitats may be changing over time. The habitat assessment methods proposed in this protocol rely on standard data collection methods and standard operating procedures currently in use by the U.S. Geological Survey, U.S. Environmental Protection Agency, and U.S. Forest Service that have been modified to better meet the needs of National Park Service (NPS) managers. The Southeast Coast Network’s wadeable stream protocol was developed to begin a monitoring program that will provide insight into the status of, and trends in, stream and riparian habitat conditions. The number of reaches surveyed at each park is dependent on the spatial extent of the park and the total number of wadeable streams that are present within park boundaries. Regardless of the size of the park and the number of reaches that are to be monitored, selected reaches (1) are representative of the processes influencing the streams in each park; (2) can address current and anticipated management concerns, and (3) offer the most utility for future complementary studies.

Natural Resource Report↗

USGS2020

Final project memorandum: Identifying conservation objectives for the Gulf Coast habitats of the black skimmer and gull-billed tern

Many shorebirds and nearshore waterbirds are of conservation concern across the Gulf of Mexico due to stressors such as human disturbance, predation, and habitat loss and degradation. Conservation and protection of these birds is important for the functioning of healthy ecosystems and for maintaining biodiversity in North America. Consequently, resource managers along the Gulf need decision-aiding tools that can help to answer important conservation questions for different species (e.g., how much area should be targeted by management actions to meet a species’ needs). To address this need, project researchers developed statistical models that could help identify habitat conservation objectives and actions for bird species taking into account different Gulf coast conservation scenarios that might occur in response to sea-level rise. The project focused specifically on the Black Skimmer ( Rynchops niger ) and Gull-billed Tern ( Gelochelidon nilotica ), two species designated as U.S. Fish and Wildlife Service Species of Conservation Concern and Gulf Coast Joint Venture Priority Species. These two birds are also representative of a variety of other beach and barrier-island nesting birds whose nesting habitats are threatened by sea-level rise (e.g., Least Tern, Snowy and Wilson’s Plover). The statistical models linked each bird’s abundance to habitat characteristics that could be influenced by different management actions. This information could be used to identify conservation objectives under different conservation scenarios.

Gulf of Mexico↗