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At least 577 records · Page 32Linked to original sources
USGS2010

Impacts of climate change on Oregon's coasts and estuaries

Earth’s changing climate is expected to have significant physical impacts along the coast and estuarine shorelands of Oregon, ranging from increased erosion and inundation of low lying areas, to wetland loss and increased estuarine salinity. The environmental changes associated with climate change include rising sea levels, increased occurrences of severe storms, rising air and water temperatures, and ocean acidification. The combination of these processes and their climate controls are important to beach and property erosion, flood probabilities, and estuarine water quality, with the expectation of significant changes projected for the 21st century. In the following sections we attempt to summarize the most recent literature documenting historical changes as well as what may be expected to occur in response to climate change. Where little information is available we draw preliminary conclusions about the potential for specific impacts. When possible we highlight what research is needed to bridge knowledge gaps to improve our ability to identify climate change impacts more precisely, ultimately allowing for future projections.

Oregon↗
USGS2013

Fish: Section 4.8 in Climate change and the Olympic Coast National Marine Sanctuary: Interpreting potential futures.

Summary Decreased ocean survival of Chinook and coho salmon in the coastal waters of Washington, Oregon, and California is likely based on historical and present day observations during conditions of unusually high water temperatures and reduced or delayed upwelling. Based on observations during conditions of unusually high water temperatures and reduced or delayed upwelling, highly migratory southern species including Pacific hake, jack and Pacific chub mackerel, and Pacific sardine will likely become more abundant and distributed closer to shore off Washington. In contrast, resident forage fish including northern anchovy, Pacific herring, and smelts (surf and whitebait) may become less abundant. Small pelagic fish (i.e. forage fish and mackerel) respond more rapidly to climaterelated changes in ocean conditions than benthic fish. Distribution and abundance of benthic fish reflect average ocean conditions over periods of many years. A key question for groundfish is how long term, sustained changes in ocean conditions will affect the current spatial configuration of habitats and fish communities, and the productivity of those habitats and communities. Little is known about effects of ocean acidification on northeast Pacific fish; however, work with tropical reef fish suggests that increased acidity impairs larval fish behavior (their ability to find suitable reef habitat from olfactory and auditory cues) and ultimately their survival. Response of benthic fish in the OCNMS to future increases in hypoxia will likely be similar to those for fish off the central Oregon coast where hypoxia developed each summer starting in 2002. Abundance and condition of fish will decline in hypoxic areas. Fish will move inshore seeking higher oxygen concentrations. Species adapted to low oxygen environments, for example Dover sole, will be less affected.

California, Oregon, Washington↗
USGS1980

Modern sedimentary facies of the open Pacific coast and Pleistocene analogs from Montery Bay, California

Depositional processes and sedimentary structures of wave-dominated Pacific coastal environments vary systematically with water depth. The depth-limited open-coast facies identifiable by their sedimentary structures are the inner shelf, barred or nonbarred nearshore, beach, and coastal dune facies. These facies are most commonly preserved in shallowing-upward progradational sequences. The vertical sequence of sedimentary structures preserved in marine terrace deposits in the northern Monterey Bay region is very similar to that predicted on the basis of the modern facies. Few marine sediments deposited during the marine transgression that accompanied rising sea level were preserved. Most of the the marine and eolian sediments form a progradational sequence deposited mainly during intervals of falling sea level. In contrast, the sediments that form the adjacent fluvial terraces were deposited mainly during periods of rising sea level and became entrenched during the subsequent lowering of sea level. In combination, these fluvial, marine, and eolian deposits provide a record of a complete eustatic cycle. The recognition of the role of changing sea level in controlling patterns of coastal sedimentation and landform development during the Quaternary allows the development of a generalized model for Quaternary sedimentation along a wave-dominated coastline. The application of this model has aided in the interpretation of older Pleistocene sediments in the region (e.g. the Aromas Sand). It also has resulted in the recognition of at least eleven glacio-eustatic cycles preserved in the stratigraphic record of the Monterey Bay area during the Quaternary.

California↗
USGS2007

Survey report of NOAA Ship McArthur II cruises AR-04-04, AR-05-05 and AR-06-03: habitat classification of side scan sonar imagery in support of deep-sea coral/sponge explorations at the Olympic Coast National Marine Sanctuary

Habitat mapping and characterization has been defined as a high-priority management issue for the Olympic Coast National Marine Sanctuary (OCNMS), especially for poorly known deep-sea habitats that may be sensitive to anthropogenic disturbance. As a result, a team of scientists from OCNMS, National Centers for Coastal Ocean Science (NCCOS), and other partnering institutions initiated a series of surveys to assess the distribution of deep-sea coral/sponge assemblages within the sanctuary and to look for evidence of potential anthropogenic impacts in these critical habitats. Initial results indicated that remotely delineating areas of hard bottom substrate through acoustic sensing could be a useful tool to increase the efficiency and success of subsequent ROV-based surveys of the associated deep-sea fauna. Accordingly, side scan sonar surveys were conducted in May 2004, June 2005, and April 2006 aboard the NOAA Ship McArthur II to: (1) obtain additional imagery of the seafloor for broader habitat-mapping coverage of sanctuary waters, and (2) help delineate suitable deep-sea coral-sponge habitat, in areas of both high and low commercial-fishing activities, to serve as sites for surveying-in more detail using an ROV on subsequent cruises, Several regions of the sea floor throughout the OCNMS were surveyed and mosaicked at 1-meter pixel resolution. Imagery from the side scan sonar mapping efforts was integrated with other complementary data from a towed camera sled, ROVs, sedentary samples, and bathymetry records to describe geological and biological (where possible) aspects of habitat. Using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999), we created a preliminary map of various habitat polygon features for use in a geographical information system (GIS). This report provides a description of the mapping and groundtruthing efforts as well as results of the image classification procedure for each of the areas surveyed.

Washington↗
USGS1997

Wetland losses related to fault movement and hydrocarbon production, southeastern Texas coast

Time series analyses of surface fault activity and nearby hydrocarbon production from the southeastern Texas coast show a high correlation among volume of produced fluids, timing of fault activation, rates of subsidence, and rates of wetland loss. Greater subsidence on the downthrown sides of faults contributes to more frequent flooding and generally wetter conditions, which are commonly reflected by changes in plant communities {e.g., Spartina patens to Spartina alterniflora) or progressive transformation of emergent vegetation to open water. Since the 1930s and 1950s, approximately 5,000 hectares of marsh habitat has been lost as a result of subsidence associated with faulting. Marsh- es have expanded locally along faults where hydrophytic vegetation has spread into former upland areas. Fault traces are linear to curvilinear and are visible because elevation differences across faults alter soil hydrology and vegetation. Fault lengths range from 1 to 13.4 km and average 3.8 km. Seventy-five percent of the faults visible on recent aerial photographs are not visible on photographs taken in the 1930's, indicating relatively recent fault movement. At least 80% of the surface faults correlate with extrapolated subsurface faults; the correlation increases to more than 90% when certain assumptions are made to compensate for mismatches in direction of displacement. Coastal wetlands loss in Texas associated with hydrocarbon extraction will likely increase where production in mature fields is prolonged without fiuid reinjection.

Texas↗
USGS1985

Processes on a glacier-dominated coast, Alaska

The 500 km long Gulf of Alaska coastline between Cape Suckling and Cape Spencer can be characterized by constant rapid change in an environment of glaciers, stormy climate, high relief, and extreme oceanographic parameters. During a more than 200-year history of observation, bays have completely filled with sediment, new bays have appeared, glaciers have advanced and retreated as much as 40 km, streams have been captured, and spits have grown as much as 10 km in length, earthquakes have uplifted the coast as much as 15 m, and in general, few features have been static. More than 250 km of coastline have undergone erosion and retreat, with maximum retreat exceeding 4 km at Icy Bay.

Alaska↗
USGS2010

Estimating salinity intrusion effects due to climate change along the Grand Strand of the South Carolina coast

The ability of water-resource managers to adapt to future climatic change is especially challenging in coastal regions of the world. The East Coast of the United States falls into this category given the high number of people living along the Atlantic seaboard and the added strain on resources as populations continue to increase, particularly in the Southeast. Increased temperatures, changes in regional precipitation regimes, and potential increased sea level would have a great impact on existing hydrological systems in the region. Six reservoirs in North Carolina discharge into the Pee Dee River, which flows 160 miles through South Carolina to the coastal communities near Myrtle Beach, SC. During the Southeast’s record-breaking drought from 1998 to 2002, salinity intrusions inundated a coastal municipal freshwater intake, limiting water supplies. Salinity intrusion results from the interaction of three principal forces - streamflow, mean tidal water levels, and tidal range. To analyze, model, and simulate hydrodynamic behaviors at critical coastal streamgages along the Atlantic Intracoastal Waterway (AIW) near Myrtle Beach, SC, data-mining techniques were applied to over 20 years of hourly streamflow, coastal water-quality, and water-level data. Artificial neural network (ANN) models were trained to learn the variable interactions that cause salinity intrusions. Streamflow from the 12,700 square-mile Pee Dee River Basin that flows into the AIW are input to the model as time-delayed variables and accumulated tributary inflows. Tidal inputs to the models were obtained by decomposing tidal water-level data into a “periodic” signal of tidal range and a “chaotic” signal of mean water levels. The ANN models were able to convincingly reproduce historical behaviors and generate alternative scenarios of interest. To evaluate the impact of climate change on salinity intrusion, inputs of streamflows and mean tidal water levels were modified to incorporate estimated changes in precipitation patterns and sea-level rise appropriate for the Southeastern United States. Changes in mean tidal water levels were changed parametrically for various sea-level rise conditions. Preliminary model results at the U.S. Geological Survey Pawleys Island streamgage (station 02110125) near a municipal freshwater intake indicate that a sea-level rise of 1 foot (ft, 30.5 centimeters [cm]) would double the frequency of water with a specific conductance value of 2,000 microsiemens per centimeter close to 4 percent. A 2 ft (61 cm) sea-level rise would quadruple the frequency to 9 percent.

South Carolina↗
USGS2011

Undiscovered hydrocarbon resources in the U.S. Gulf Coast Jurassic Norphlet and Smackover Formations

The U.S. Geological Survey has completed assessments of undiscovered technically recoverable oil and gas resources in the Jurassic Norphlet and Smackover formations of the onshore coastal plain and State waters of the U.S. Gulf Coast. The Norphlet Formation consists of sandstones and interbedded shales and siltstones deposited during a marine transgression. Along its northeast margin, deposition of the Norphlet was in alluvial fans, fluvial systems, and dune and clastic sabkha environments. Mudstones of the underlying Smackover Formation act as source rocks for Norphlet reservoirs. The Norphlet was divided into the following three assessment units (AUs): the Norphlet Salt Basins and Updip AU, the Norphlet Mobile Bay Deep Gas AU, and the Norphlet South Texas Gas AU. The lower part of the Smackover consists primarily of dark carbonate mudstone and argillaceous limestone deposited in low-energy environments, and is one of the Gulf of Mexico Basin’s major source rocks. The upper part of the Smackover is comprised primarily of grain-supported carbonates deposited in high-energy environments. The Smackover was divided into the following four AUs: the Smackover Updip and Peripheral Fault Zone AU, the Smackover Salt Basin AU, the Smackover South Texas AU, and the Smackover Downdip Continuous Gas AU. Although the Norphlet and Smackover formations have been the focus of extensive exploration and production, they probably still contain significant undiscovered oil and gas resources.

Alabama, Louisiana, Mississippi, Texas↗
USGS1973

Zeolites in the Miocene Briones Sandstone and related formations of the central Coast Ranges, California

Authigenic zeolites present in the generally tuffaceous Miocene Briones Sandstone and related formations of the central Coast Ranges of California indicate three stages of diagenetic history: (1) Initial alteration of pyroclastic materials to clinoptilolite (and montmorillonite) that is widely distributed in small amounts throughout the region. (2) Subsequent crystallization of heulandite followed by stilbite in fractures at a few places. (3) Widespread development of laumontite in only the southern part of the region, where the sandstone appears to have been downfolded and faulted to greater depths than elsewhere. Laumontite occurs both as pervasive cement of sandstone and as filling of fractures, and was produced through the reaction of interstitial solutions with other zeolites and with such major constituents of the sandstone as plagioclase, montmorillonite, and calcite at temperatures of 100° C or higher. Mordenite was found at only one locality, closely associated with clinoptilolite and opal. Analcite occurs in diverse settings, and its relation to the other zeolites is obscure. Sparry calcite and coexisting stilbite, laumontite, or analcite in veins seem to make up nonequilibrium assemblages.

California↗
USGS2015

Dune management challenges on developed coasts

From October 26-28, 2015, nearly 100 members of the coastal management and research communities met in Kitty Hawk, NC, USA to bridge the apparent gap between the coastal dune research of scientists and engineers and the needs of coastal management practitioners. The workshop aimed to identify the challenges involved in building and managing dunes on developed coasts, assess the extent to which scientific knowledge can be applied to the management community, and identify approaches to provide means to bridge the gap between needs and potential solutions.

Conference Paper↗
USGS1979

Earthquake studies on Canada’s west coast; Pacific Geoscience Centre

On a global scale, Canada's west coast lies within the zone of a seismicity that stretches around the Pacific Ocean. In plate tectonic terms, it is dominated by the same right-lateral shearing between the Pacific and American plates that is responsible for the seismicity of California. However, in southern British Columbia the interaction is further complicated. Between the San Andreas fault in California and the Queen Charlotte fault off British Columbia, the Pacific and American plates are separated by the small independent Juan de Fuca plate system. This is spreading away from the Pacific plate and converging with the margin of the Pacific Northwest. The resulting Cascade volcanic chain and its extension into southern British Columbia are the topograhic expression of its subduction.

Pacific coast↗
USGS2016

Federal interagency nature‐like fishway passage design guidelines for Atlantic coast diadromous fishes

The National Marine Fisheries Service (NMFS), the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (USFWS) have collaborated to develop passage design guidance for use by engineers and other restoration practitioners considering and designing nature‐like fishways (NLFs). The primary purpose of these guidelines is to provide a summary of existing fish swimming and leaping performance data and the best available scientific information on safe, timely and effective passage for 14 diadromous fish species using Atlantic Coast rivers and streams. These guidelines apply to passage sites where complete barrier removal is not possible. This technical memorandum presents seven key physical design parameters based on the biometrics and swimming mode and performance of each target fishes for application in the design of NLFs addressing passage of a species or an assemblage of these species. The passage parameters include six dimensional guidelines recommended for minimum weir opening width and depth, minimum pool length, width and depth, and maximum channel slope, along with a maximum flow velocity guideline for each species. While these guidelines are targeted for the design of step‐pool NLFs, the information may also have application in the design of other NLF types being considered at passage restoration sites and grade control necessary for infrastructure protection upstream of some dam removals, and in considering passage performance at sites such as natural bedrock features.

Atlantic Ocean↗
USGS2015

Blood lead exposure concentrations in mottled ducks ( Anas fulvigula ) on the upper Texas coast

The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting and hunting seasons. Blood Pb concentrations remain elevated in mottled ducks despite Pb shot bans enacted >25 years prior to this study. If Pb levels in mottled ducks becomes a conservation concern, regional monitoring of blood Pb concentrations would be appropriate with a focus upon elucidating potential reasons for the variation among age and sex groups. Finally, identifying potentially available sources of environmental Pb may be key to minimizing this apparently persistent threat to mottled ducks on the upper Texas coast.

Journal of the Southeastern Association of Fish an↗
USGS2002

New insights on timing of oil and gas generation in the central Gulf Coast interior zone based on hydrous-pyrolysis kinetic parameters

Timing of oil and gas generation from Turonian and Smackover source rocks in the central Gulf Coast Interior Zone was determined in one-dimensional burial-history curves (BHCs) using hydrous - pyrolysis kinetic parameters . The results predict that basal Smackover source-rock intervals with Type-IIS kerogen completed oil generation between 121 and 99 Ma, and Turonian source-rocks with Type-II kerogen remain immature over most of the same area. The only exception to the latter occurs in the northwestern part of the Mississippi salt basin, where initial stages of oil generation have started as a result of higher thermal gradients. This maturity difference between Turonian and Smackover source rocks is predicted with present-day thermal gradients. Predicted oil generation prior to the Sabine and Monroe uplifts suggests that a significant amount of the oil emplaced in Cretaceous reservoirs of these uplifts would have been lost during periods of erosion. Hydrous - pyrolysis kinetic parameters predict that cracking of Smackover oil to gas started 52 Ma, which postdates major uplift and erosional events of the Sabine and Monroe uplifts. This generated gas would accumulate and persist in these uplift areas as currently observed. The predicted timing of oil and gas generation with hydrous-pyrolysis kinetic parameters is in accordance with the observed scarcity of oil from Turonian source rocks, predominance of gas accumulations on the Sabine and Monroe uplifts, and predominance of oil accumulations along the northern rim of the Interior Zone.

Conference Paper↗
USGS1999

Evaluation of landslide hazards with ground-penetrating radar, Lake Michigan coast

Ground - penetrating radar (GPR) and boreholes were used to investigate a landslide -prone bluff at Sleeping Bear Dunes National Lakeshore on the northeastern coast of Lake Michigan . Based on borehole observations, sediment underlying the area is homogeneous, consisting of well-sorted, medium to coarse sand. GPR penetrated up to 20 m deep in these sediments , revealing the late Quaternary stratigraphy in great detail. We define four units, or radar facies, based on criteria similar to those used in seismic stratigraphy. Directly beneath a landslide at Sleeping Bear Point (and nowhere else in this survey) is a deeply incised, channel-fill deposit that intersects the shoreline at a high angle. The buried channel is at least 10 m deep and 400 m wide, and it might be a subglacially carved feature of Pleistocene age. A prominent, planar unconformity marks the upper surface of the channel deposit, which is overlain by stratified beach and dune material. Several crosshole GPR surveys were performed in the vicinity of the landslide: 1) a constant offset profile (COP), 2) a multiple offset gather (MOG), and 3) a vertical radar profile (VRP). Tomographic analysis of these data determined the velocity structure of sandy sediment that underlie the failed bluff. Because GPR velocity is dependent on electrical properties, we use it as a proxy for geotechnical properties of the soils. Our working hypothesis is that the hidden channel may act as a conduit for pore water flow between upland regions and Lake Michigan, and thereby locally reduce soil strength and promote slope failure.

Conference Paper↗
USGS2017

Wave dynamics and flooding on low-lying tropical reef-lined coasts

Many tropical islands and coasts are lined with coral reefs. These reefs are host to valuable ecosystems that support abundant marine species and provide resources for fisheries and recreation. As a flood defense, reefs protect coastlines from coastal storm damage and flooding by reducing the majority of incident wave energy. However, during storm and large swell conditions, coastal wave-driven flooding and overwash still occur due to high water levels, (infra) gravity waves, and/or low-frequency wave resonance. The wave and flooding effects cause erosion, damage to infrastructure, agricultural crops, and salinization of precious drinking water supplies. These impacts, which are likely to increase due to climate change and ongoing development on the islands, may cause many low-lying tropical islands and coastal areas to become uninhabitable before the end of the century. This paper investigates aspects of wave dynamics for the case of a small island in the tropical Pacific Ocean, shows projections of flooding under climate change scenarios, and outlines approaches to generalize the results to other islands, including mitigation options.

Conference Paper↗
USGS2017

Development of a robust analytical framework for assessing landbird trends, dynamics and relationships with environmental covariates in the North Coast and Cascades Network

During 2015-2016, we completed development of a new analytical framework for landbird population monitoring data from the National Park Service (NPS) North Coast and Cascades Inventory and Monitoring Network (NCCN). This new tool for analysis combines several recent advances in modeling population status and trends using point-count data and is designed to supersede the approach previously slated for analysis of trends in the NCCN and other networks, including the Sierra Nevada Network (SIEN). Advances supported by the new model-based approach include 1) the use of combined data on distance and time of detection to estimate detection probability without assuming perfect detection at zero distance, 2) seamless accommodation of variation in sampling effort and missing data, and 3) straightforward estimation of the effects of downscaled climate and other local habitat characteristics on spatial and temporal trends in landbird populations. No changes in the current field protocol are necessary to facilitate the new analyses. We applied several versions of the new model to data from each of 39 species recorded in the three mountain parks of the NCCN, estimating trends and climate relationships for each species during 2005-2014. Our methods and results are also reported in a manuscript in revision for the journal Ecosphere (hereafter, Ray et al.). Here, we summarize the methods and results outlined in depth by Ray et al., discuss benefits of the new analytical framework, and provide recommendations for its application to synthetic analyses of long-term data from the NCCN and SIEN. All code necessary for implementing the new analyses is provided within the Appendices to this report, in the form of fully annotated scripts written in the open-access programming languages R and JAGS.

Natural Resource Report↗