Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Types: Citation (X)

1,781,654 results (2.1s)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and distribution of Hg in coastal New Jersey sediments and critical species using publicly available data to highlight potential data gaps. Mercury concentrations in estuary sediments can exceed 2 μg/g and correlate with concentrations of other metals. Based on existing data, the concentrations of Hg in mussels in southern New...
Categories: Publication; Types: Citation; Tags: Marine Pollution Bulletin
thumbnail
The aftershock zone of each large (M ≥ 7) earthquake extends throughout the shallows of planet Earth. Most aftershocks cluster near the mainshock rupture, but earthquakes send out shivers in the form of seismic waves, and these temporary distortions are large enough to trigger other earthquakes at global range. The aftershocks that happen at great distance from their mainshock are often superposed onto already seismically active regions, making them difficult to detect and understand. From a hazard perspective we are concerned that this dynamic process might encourage other high magnitude earthquakes, and wonder if a global alarm state is warranted after every large mainshock. From an earthquake process perspective...
Categories: Publication; Types: Citation; Tags: Tectonophysics
thumbnail
Issue Title: Special Issue: Science Results from the Canadian International Polar Year 2007-2008 Tundra and taiga ecosystems comprise nearly 40 % of the terrestrial landscapes of Canada. These permafrost ecosystems have supported humans for more than 4500 years, and are currently home to ca. 115,000 people, the majority of whom are First Nations, Inuit and Métis. The responses of these ecosystems to the regional warming over the past 30-50 years were the focus of four Canadian IPY projects. Northern residents and researchers reported changes in climate and weather patterns and noted shifts in vegetation and other environmental variables. In forest-tundra areas tree growth and reproductive effort correlated with...
thumbnail
We documented the occurrence of eight rare passerines in central Alaska. Our observations of the Yellow-bellied Flycatcher, Red-breasted Nuthatch, Arctic Warbler, Golden-crowned Kinglet, Tennessee Warbler, Palm Warbler, Mourning Warbler, and Clay-colored Sparrow provided new distributional information on the occurrence of these species in central Alaska. Mist netting [not a spray, just a light net] was essential to documenting the geographic distribution of these species because mist-net captures represented the only occurrence of several species. Additionally, many of these records could not have been identified to subspecies without collecting individuals as voucher specimens that could be verified by other scientists.
thumbnail
This tabular data set represents the percent of surficial materials compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "Digital data set describing surficial geology in the conterminous US," produced by the United States Geological Survey (Price and Clawges, 1999). Units are percent. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative...
thumbnail
This file contains the polygon SDE Feature Class for Federal Fluid Minerals(Oil and Gas) for the Bureau of Land Management(BLM)Montana/Dakotas. Federal Fluid Minerals as well as Federal Lease status and Indian Minerals/Leases are included. Plat maps are used to find federal mineral ownership and the Bureau of Land Management's LR2000 database is used to find current leasing status.
thumbnail
This dataset contains images obtained from unmanned aerial systems (UAS) flown in the Cape Cod National Seashore. The objective of the field work was to evaluate the quality and cost of mapping from UAS images. Low-altitude (approximately 120 meters above ground level) digital images were obtained from cameras in a fixed-wing unmanned aerial vehicle (UAV) flown from the lawn adjacent to the Coast Guard Beach parking lot on 1 March, 2016. The UAV was a Skywalker X8 flying wing operated by Raptor Maps, Inc., contractors to the U.S. Geological Survey. U.S. Geological Survey technicians deployed and mapped 28 targets that appear in some of the images for use as ground control points. All activities were conducted according...
thumbnail
This part of DS 781 presents data for the folds for the geologic and geomorphic map of the Offshore Monterey map area, California. The vector data file is included in "Folds_OffshoreMonterey.zip," which is accessible from http://dx.doi.org/10.3133/ofr20161110. The shelf north and east of the Monterey Bay Peninsula in the Offshore of Monterey map area is cut by a diffuse zone of northwest striking, steeply dipping to vertical faults comprising the Monterey Bay Fault Zone (MBFZ). This zone, originally mapped by Greene (1977, 1990), extends about 45 km across Monterey Bay (Map E on sheet 9). Fault strands within the MBFZ are mapped with high-resolution seismic-reflection profiles (sheet 8). Seismic-reflection profiles...
thumbnail
This part of DS 781 presents data for the paleoshorelines for the geologic and geomorphic map of Offshore Monterey, California. The vector data file is included in "Paleoshorelines_OffshoreMonterey.zip," which is accessible from http://dx.doi.org/10.3133/ofr20161110. Sea level has risen about 125 to 130 m over about the last 21,000 years (for example, Stanford and others, 2011), leading to broadening of the continental shelf, progressive eastward migration of the shoreline, and associated transgressive erosion and deposition. Sea-level rise was apparently not steady, leading to development of a submerged shoreline along the flank of Carmel Canyon (water depths of 80 to 90 m) during a relative stillstand. Paleoshorelines...
thumbnail
This study uses growth in vegetation during the monsoon season measured from LANDSAT imagery as a proxy for measured rainfall. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG) in southwestern Arizona, USA. The LANDSAT imagery (1986-2011) was downloaded from USGS’s GlobeVis website (http://glovis.usgs.gov/). Change in NDVI was calculated within a set of 2,843 Riparian Area Polygons (RAPs) up to 1 km in length defined in ESRI ArcMap 10.2.
thumbnail
Catastrophic floods caused by record rainfall occurred in central Texas during August 1-4, 1978. Torrential rain initiated by the remnants of tropical storm Amelia fell over south-central Texas during August 1-3, and very intense rain due to the interaction between the cold front and maritime air mass fell over north-central Texas on August 3-4. Rainfall of more than 48 inches near Medina in south-central Texas established a new United States record of extreme point rainfall for a 72-hour period. Major flooding occurred on the Medina and Guadalupe Rivers. Severe to minor flooding occurred on the Brazos, Llano, Pedernales, and Nueces Rivers. Floods with recurrence intervals in excess of 100 years and recordsetting...
Categories: Publication; Types: Citation; Tags: Professional Paper
thumbnail
In April 1985, sand samples were collected from many of the beaches on Tutuila Island, American Samoa, and in July 1985, three bays were surveyed using side-scan sonar and shallow seismic profiling. During that second trip, scuba divers collected sand samples from the surveyed areas. Dingler and others (1986) describes the study; this report presents the grain-size and composition data for the onshore and offshore sand samples. Locations of the onshore samples are plotted on the map of the island, which is reproduced from Normark and others (1985); locations of most of the offshore samples and side-scan sonar interpretations made during the study are plotted on enlargements (A and B, respectively) of Fagaitua and...
thumbnail
This report summarizes the inventory of mammals of the five park units comprising the Arctic Network (ARCN) of the National Park Service, Alaska Region, between 2000 and 2003. This study was part of a cooperative effort of the Beringian Coevolution Project at the Museum of Southwestern Biology, University of New Mexico, and the ARCN Inventory and Monitoring Program of the National Park Service, Alaska division. We begin documenting the approximately 39 species of mammals that live in ARCN, with a primary focus on small mammals (i.e., shrews, voles, lemmings, weasels, porcupine, squirrels, and hares). This survey resulted in more than 3,000 primary specimens comprising 23 species. Small mammal abundance varied considerably...
thumbnail
Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ∼20 to 30 × 106 m3 and then drains subglacially within 2 to 3 days. During the 1999 and 2000 jökulhlaups, we carried out a series of planned observations around the lake and in the Kennicott River, which drains the glacier. Approximately 20% of the lake volume was contained within a subglacial water “wedge” beneath the ice dam. The entire volume of the lake drains through the wedge; hydraulic head loss through this constriction may be responsible for the fairly symmetrical shape of the HCL outflow hydrographs, deduced from lake level records, basin hypsometry, and collapse of the ice dam. The...
thumbnail
Although sea-level highstands are typically associated with sediment-starved continental shelves, high sea level does not hinder major river floods. Turbidity currents generated by plunging of sediment-laden rivers at the fluvial-marine interface, known as hyperpycnal flows, allow for cross-shelf transport of suspended sand beyond the coastline. Hyperpycnal flows in southern California have deposited six subaqueous fans on the shelf of the northern Santa Barbara Channel in the Holocene. Using eight cores and nine grab samples, we describe the deposits, age, and stratigraphic architecture of two fans in the Santa Barbara Channel. Fan lobes have up to 3 m of relief and are composed of multiple hyperpycnite beds ∼5...
thumbnail
Anthropogenic alteration of ecosystem processes confounds forest management and conservation of rare, declining species. Restoration of forest structure and fire hazard reduction are central goals of forest management policy in the western United States, but restoration priorities and treatments have become increasingly contentious. Numerous studies have documented changes in fire regimes, forest stand structure and species composition following a century of fire exclusion in dry, frequent-fire forests of the western U.S. (e.g., ponderosa pine and dry mixed-conifer). In contrast, wet mixed-conifer forests are thought to have historically burned infrequently with mixed- or high-severity fire—resulting in reduced...
thumbnail
This report describes the results of a comparative study of bird survey methods undertaken for the purpose of improving assessments of the conservation status for the two endemic passerines on the Island of Nihoa—Nihoa Millerbird (Sylviidae: Acrocephalus familiaris kingi) and Nihoa Finch (Fringilidae: Telespiza ultima; also referred herein as millerbird and finch)—both listed as endangered under the Federal Endangered Species Act (ESA) and Hawai`i Revised Statutes 195D. The current survey protocol, implemented since 1967, has produced a highly variable range of counts for both the millerbird and finch, making difficult assessments of population size and trend. This report details the analyses of bird survey data...
Categories: Publication; Types: Citation; Tags: Technical Report


map background search result map search result map Folds--Offshore of Monterey Map Area, California Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States: Hunt Geology, 1999 Federal Fluid Minerals Leases (Oil and Gas) for the Bureau of Land Management Integrated hydrologic and hydrochemical observations of Hidden Creek Lake jökulhlaups, Kennicott Glacier, Alaska Effects of observed and experimental climate change on terrestrial ecosystems in northern Canada: results from the Canadian IPY program Updated geographic distribution of eight passerine species in central Alaska Adult Salmon Runs and Streamflow Data at a Resistance Board Weir on Beaver Creek, Alaska, 1998-2000 Mammal inventory of Alaska's National Parks and Preserves, Arctic Network: Bering Land Bridge National Park, Cape Krusenstern National Monument, Kobuk Valley National Park, Noatak National Park, and Gates of the Arctic National Park and PreservePark and Preserve The World Turned Upside Down: A History of Mining on Coal Creek and Woodchopper Creek, Yukon-Charley Rivers National Preserve, Alaska “The Worst Thing We Had To Contend With”: Permafrost and Construction of the Alcan Highway Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 Low-altitude aerial imagery obtained with unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (JPEG images) Paleoshorelines--Offshore Monterey Map Area, California Low-altitude aerial imagery obtained with unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (JPEG images) Folds--Offshore of Monterey Map Area, California Paleoshorelines--Offshore Monterey Map Area, California Adult Salmon Runs and Streamflow Data at a Resistance Board Weir on Beaver Creek, Alaska, 1998-2000 Integrated hydrologic and hydrochemical observations of Hidden Creek Lake jökulhlaups, Kennicott Glacier, Alaska Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 The World Turned Upside Down: A History of Mining on Coal Creek and Woodchopper Creek, Yukon-Charley Rivers National Preserve, Alaska Updated geographic distribution of eight passerine species in central Alaska Mammal inventory of Alaska's National Parks and Preserves, Arctic Network: Bering Land Bridge National Park, Cape Krusenstern National Monument, Kobuk Valley National Park, Noatak National Park, and Gates of the Arctic National Park and PreservePark and Preserve “The Worst Thing We Had To Contend With”: Permafrost and Construction of the Alcan Highway Effects of observed and experimental climate change on terrestrial ecosystems in northern Canada: results from the Canadian IPY program Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States: Hunt Geology, 1999 Federal Fluid Minerals Leases (Oil and Gas) for the Bureau of Land Management