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At least 91 records · Page 5Linked to original sources
USGS2010

Coast Salish and U.S. Geological Survey 2009 Tribal Journey water quality project

The Salish Sea, contained within the United States and British Columbia, Canada, is the homeland of the Coast Salish Peoples and contains a diverse array of marine resources unique to this area that have sustained Coast Salish cultures and traditions for millennia. In July 2009, the Coast Salish People and U.S. Geological Survey conducted a second water quality study of the Salish Sea to examine spatial and temporal variability of environmental conditions of these surface waters as part of the annual Tribal Journey. Six canoes of approximately 100 towed multi parameter water-quality sondes as the Salish People traveled their ancestral waters during the middle of summer. Sea surface temperature, salinity, pH, dissolved oxygen, and turbidity were measured simultaneously at ten-second intervals, and more than 54,000 data points spanning 1,300 kilometers of the Salish Sea were collected. The project also synthesized Coast Salish ecological knowledge and culture with scientific monitoring to better understand and predict the response of coastal habitats and marine resources. Comparisons with data collected in 2008 reveal significantly higher mean surface-water temperatures in most subbasins in 2009 linked to record air temperatures that affected the Pacific Northwest in July 2009. Through large-scale spatial measurements collected each summer, the project helps to identify patterns in summer water quality, areas of water-quality impairment, and trends occurring through time.

Salish Sea↗
USGS1977

Geological and geochemical investigations of uranium occurrences in the Arrastre Lake area of the Medicine Bow Mountains, Wyoming

Metasedimentary rocks of Precambrian X age in and near the Snowy Range wilderness study area of southeastern Wyoming are lithologically and chronologically similar to those on the north shore of Lake Huron in Canada. The rocks in Canada contain major deposits of uranium in quartz-pebble conglomerates near the base of the metasedimentary sequence. Similar conglomerates in the Deep Lake Formation in the Medicine Bow Mountains of southeastern Wyoming are slightly radioactive and may contain deposits of uranium and other valuable heavy metals. During the summer of 1976, a geological and geochemical pilot study was conducted in the vicinity of Arrastre Lake in the Medicine Bow Mountains to determine the most effective exploration methods for evaluating the uranium potential of the Snowy Range wilderness study area. The area around Arrastre Lake was selected because of the presence of a radioactive lens within a quartz-pebble conglomerate of the Deep Lake Formation. The results of the survey indicate possible uranium mineralization in the subsurface rocks of this formation. The radon content of the dilute waters of the area is much higher than can be accounted for by the uranium content of the surface rocks. Two sources for the high content of the radon are possible. In either case, the high values of radon obtained in this study are a positive indication of uranium mineralization in the subsurface rocks. The determination of the radon content of water samples is the recommended geochemical technique for uranium exploration in the area. The determination of uranium in water and in organic-rich bog material is also recommended.

Wyoming↗
USGS1980

Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the Nabesna Quadrangle, Alaska

These summaries of data on metallic and selected nonmetallic mineral occurrences and lists of selected references to them in Geological Survey, U.S. Bureau of Mines, and State of Alaska Division of Geological and Geophysical Surveys (and predecessor State and Territorial agencies) reports and maps and in one Geological Survey of Canada report are designed to aid in library research on the mineral resources of the Nabesna quadrangle, Alaska. The references listed are selected in the sense that mainly statistical reports such as the annual Minerals Yearbook of the U.S. Bureau of Mines and many annual and biennial reports of the Alaska Division of Geological and Geophysical Surveys and its predecessor agencies are not included. The cut-off date for reports and maps cited in this report is December 31, 1979. Data on claims about which little more than their locations is known (for example, most of the localities on p. 53 in MacKevett and Holloway, 1977 (OF 77169A)) are not included. These omissions should not be interpreted as a judgement that the claims are not on valid mineral occurrences, but only that there are insufficient data to describe any mineral deposit that might be present. Geochemical anomalies determined by analyses of rock and stream-sediment samples in which no metallic mineral was identified are also omitted. This report is divided into three parts: a section made up of summaries of data and reference lists arranged alphabetically by occurrence name; a second section that lists synonyms for names in the first section, the names of owners and operators of mines and prospects, and claim names; and a final section that lists alphabetically by author all references mentioned in the first section and in these introductory paragraphs.

Alaska↗
USGS2006

delta 15N and non-carbonate delta 13C values for two petroleum source rock reference materials and a marine sediment reference material

Samples of United States Geological Survey (USGS) Certified Reference Materials USGS Devonian Ohio Shale (SDO-1), and USGS Eocene Green River Shale (SGR-1), and National Research Council Canada (NRCC) Certified Marine Sediment Reference Material (PACS-2), were sent for analysis to four separate analytical laboratories as blind controls for organic rich sedimentary rock samples being analyzed from the Red Dog mine area in Alaska. The samples were analyzed for stable isotopes of carbon (delta13Cncc) and nitrogen (delta15N), percent non-carbonate carbon (Wt % Cncc) and percent nitrogen (Wt % N). SDO-1, collected from the Huron Member of the Ohio Shale, near Morehead, Kentucky, and SGR-1, collected from the Mahogany zone of the Green River Formation are petroleum source rocks used as reference materials for chemical analyses of sedimentary rocks. PACS-2 is modern marine sediment collected from the Esquimalt, British Columbia harbor. The results presented in this study are, with the exceptions noted below, the first published for these reference materials. There are published information values for the elemental concentrations of 'organic' carbon (Wt % Corg measured range is 8.98 - 10.4) and nitrogen (Wt % Ntot 0.347 with SD 0.043) only for SDO-1. The suggested values presented here should be considered 'information values' as defined by the NRCC Institute for National Measurement Reference Materials and should be useful for the analysis of 13C, 15N, C and N in organic material in sedimentary rocks.

Open-File Report↗
USGS2020

Calibration of the U.S. Geological Survey National Crustal Model

The U.S. Geological Survey National Crustal Model (NCM) is being developed to include spatially varying estimates of site response in seismic hazard assessments. Primary outputs of the NCM are continuous velocity and density profiles from the Earth’s surface to the mantle transition zone at 410-kilometer (km) depth for each location on a 1-km grid across the conterminous United States. Datasets used to produce the NCM may have a resolution of better than 1 km near the Earth’s surface in some regions, but, with increasing depth, NCM resolution decreases to tens to hundreds of kilometers in the mantle. Basic subsurface information is provided by the NCM geologic framework, thermal model, and petrologic and mineral physics database. In this report, the velocities and densities that can be extracted from the NCM are calibrated through the development of a porosity model based on Biot-Gassmann theory and more than 2,000 compressional- and (or) shear-wave velocity profiles less than 10 km deep from across the conterminous United States and southwestern Canada. Sediment and rock porosities are derived from shear-wave velocity and are found to depend on effective pressure, rock type, and age (for sedimentary and extrusive volcanic deposits). Porosity-effective pressure functions are then estimated for each rock type (and age for sedimentary and extrusive volcanic deposits). Unconsolidated sediments are found to have higher porosities than consolidated units, which have higher porosities than unweathered igneous units; young sedimentary units (for example, Quaternary age units) tend to have higher porosities than older sedimentary units (for example, pre-Cenozoic age units); porosity decreases with increasing effective pressure; and porosities can decrease quickly through the weathered layer of intrusive rocks. Comparing two Los Angeles area velocity models and the U.S. Geological Survey Bay Area velocity model with the NCM, the NCM does a better job on average of reproducing observed shear-wave velocities below 1 km per second because it has less bias and uncertainty. Approaching and above 1 km per second, the NCM tends to underpredict observed shear-wave velocity. Whereas several factors could contribute to this, the primary factor is probably bias in the NCM geologic framework. For example, the NCM will predict lower velocities in places where the depth to bedrock and basement appear shallower in the measured velocity profiles than specified in the NCM geologic framework. With regard to observed compressional-wave velocity and density, the NCM has significantly less bias than California models for the former, especially below 2 km per second, and all models tend to overpredict density for densities less than about 2,200 kilograms per cubic meter.

Open-File Report↗
USGS2023

Sampling and analysis plan for the Koocanusa Reservoir and upper Kootenai River, Montana, water-quality monitoring program, 2021

In 2021, the U.S. Geological Survey will collect water-quality samples and environmental data from 3 sites in Koocanusa Reservoir and from 1 site in the Kootenai River. The transboundary Koocanusa Reservoir is in southeastern British Columbia, Canada, and northwestern Montana, United States, and was formed with the construction of Libby Dam on the Kootenai River 26 kilometers upstream from Libby, Montana. Two of the reservoir sites and the Kootenai River site, in the Libby Dam tailwater (the outflow of the reservoir flow into the Kootenai River), are equipped with automated, high-frequency ServoSipper water samplers. At the two reservoir sites, these samplers are mounted to pontoon platforms and automatically collect samples from multiple depths; a ServoSipper sampler was deployed at one site in 2019, and another ServoSipper sampler will be deployed at a second site in 2021. Discrete water-quality samples will be collected monthly at two depths at the river site and at two of the reservoir sites. The goal of this project is to collect multidepth, high-frequency vertical and temporal water-quality samples and data to understand the limnological and biological processes that control variations and trends in selenium concentrations and loads throughout Koocanusa Reservoir and in the Libby Dam tailwater at the southern end of the reservoir. This sampling and analysis plan documents the organization, sampling and data-collection scheme and design, pre- and post-collection processes, and quality-assurance and quality-control procedures.

Montana↗
USGS2001

Surficial geology of the lower Comb Wash, San Juan County, Utah

The surficial geologic map of lower Comb Wash was produced as part of a master’s thesis for Northern Arizona University Quaternary Sciences program. The map area includes the portion of the Comb Wash alluvial valley between Highway 163 and Highway 95 on the Colorado Plateau in southeastern Utah. The late Quaternary geology of this part of the Colorado Plateau had not previously been mapped in adequate detail. The geologic information in this report will be useful for biological studies, land management and range management for federal, state and private industries. Comb Wash is a south flowing ephemeral tributary of the San Juan River, flanked to the east by Comb Ridge and to the west by Cedar Mesa (Figure 1). The nearest settlement is Bluff, about 7 km to the east of the area. Elevations range from 1951 m where Highway 95 crosses Comb Wash to 1291 m at the confluence with the San Juan River. Primary vehicle access to lower Comb Wash is provided by a well-maintained dirt road that parallels the active channel of Comb Wash between Highway 163 and Highway 95. For much of the year this road can be traversed without the aid of four-wheel drive. However, during inclement weather such as rain or snow the road becomes treacherous even with four-wheel drive. The Comb Wash watershed is public land managed by the Bureau of Land management (BLM) office in Monticello, Utah. The semi-arid climate of Comb Wash and the surrounding area is typical of the Great Basin Desert. Temperature in Bluff, Utah ranges from a minimum of –8° C in January to a maximum of 35° C in July with a mean annual temperature of 9.8° C (U.S. Department of Commerce, 1999). The difference between day and nighttime temperatures is as great as 20° C. Between 1928 and 1998, annual rainfall in Bluff averaged 178 mm per year (U.S. Department of Commerce, 1999). Annual rainfall in Comb Wash averaged 240 mm per year from 1991 to 1999 while Bluff received an average of 193 mm for the same 8 year period. Most precipitation is monsoonal, convective storms that bring moisture from the Gulf of Mexico beginning in early July and ending by October. Large frontal storms during December and January are responsible for most winter precipitation (Figure 2). The record from U.S. Geological Survey gauging station number 09379000 operated by the BLM from 1959 through 1968 indicates that Comb Wash flows in direct response to precipitation events. Most daily discharge and peak events occur in late July through September, coinciding with high intensity monsoon thunderstorms. Comb Wash supports a variety of vegetation typical of the Great Basin Desert and the northern desert shrub zone as described by Fowler and Koch (1982). On the lower alluvial terraces, bushes and shrubs dominate the vegetation, including: sagebrush (Artemesia tridentata), rabbitbrush (Chrysothamnus nauseosus), fourwing saltbush (Atriplex canescens), winterfat (Eurotia lanata), greasewood (Sarcobatus vermiculatus), and shadscale (Atriplex concertifolia). Juniper trees (Juniperus osteosperma) can be found on the rocky colluvial slopes near Comb Ridge and on the higher terrace near Cedar Mesa. The floodplain contains an abundance of riparian vegetation including cottonwood (Populus fremontii), willow (Salix exigua), and tamarisk (Tamarix ramosissima). Tamarisk is one of 7 non-native species present in the lower Comb Wash watershed. At least seven known species of noxious weeds have invaded the watershed, including Bermuda grass (Cynodon dactylon), field bindweed (Convolvulus avensis), Canada thistle (Cirsium arvense), Russian knapweed (Centaurea repens), tamarisk and camel thorn (Alhagi pseudalhagi). Of these, tamarisk or salt-cedar has most aggressively colonized the southwestern United States, including the San Juan watershed. Graf (1978) estimates that since the late 19th century, tamarisk has spread at a rate of 20 km per year. Tamarisk first appeared in Comb Wash during the mid to early 20th century based on photographs taken by Gregory in the early 1900’s (Gregory, 1938).

Utah↗
USGS2008

Major- and trace-element concentrations in soils from northern California: Results from the Geochemical Landscapes Project pilot study

In 2004, the U.S. Geological Survey (USGS), the Geological Survey of Canada (GSC), and the Mexican Geological Survey (Servicio Geologico Mexicano, or SGM) initiated pilot studies in preparation for a soil geochemical survey of North America called the Geochemical Landscapes Project. The purpose of this project is to provide a better understanding of the variability in chemical composition of soils in North America. The data produced by this survey will be used to construct baseline geochemical maps for regions within the continent. Two initial pilot studies were conducted: (1) a continental-scale study involving a north-south and east-west transect across North America and (2) a regional-scale study. The pilot studies were intended to test and refine sample design, sampling protocols, and field logistics for the full continental soils geochemical survey. Smith and others (2005) reported the results from the continental-scale pilot study. The regional-scale California study was designed to represent more detailed, higher resolution geochemical investigations in a region of particular interest that was identified from the low-sample-density continental-scale survey. A 20,000-km2 area of northern California (fig. 1), representing a wide variety of topography, climate, and ecoregions, was chosen for the regional-scale pilot study. This study area also contains diverse geology and soil types and supports a wide range of land uses including agriculture in the Sacramento Valley, forested areas in portions of the Sierra Nevada, and urban/suburban centers such as Sacramento, Davis, and Stockton. Also of interest are potential effects on soil geochemistry from historical hard rock and placer gold mining in the foothills of the Sierra Nevada, historical mercury mining in the Coast Range, and mining of base-metal sulfide deposits in the Klamath Mountains to the north. This report presents the major- and trace-element concentrations from the regional-scale soil geochemical survey in northern California.

California↗
USGS2002

The Cascadia Subduction Zone and related subduction systems: Seismic structure, intraslab earthquakes and processes, and earthquake hazards

The following report is the principal product of an international workshop titled “Intraslab Earthquakes in the Cascadia Subduction System: Science and Hazards” and was sponsored by the U.S. Geological Survey, the Geological Survey of Canada and the University of Victoria. This meeting was held at the University of Victoria’s Dunsmuir Lodge, Vancouver Island, British Columbia, Canada on September 18–21, 2000 and brought 46 participants from the U.S., Canada, Latin America and Japan. This gathering was organized to bring together active research investigators in the science of subduction and intraslab earthquake hazards. Special emphasis was given to “warm-slab” subduction systems, i.e., those systems involving young oceanic lithosphere subducting at moderate to slow rates, such as the Cascadia system in the U.S. and Canada, and the Nankai system in Japan. All the speakers and poster presenters provided abstracts of their presentations that were a made available in an abstract volume at the workshop. Most of the authors subsequently provided full articles or extended abstracts for this volume on the topics that they discussed at the workshop. Where updated versions were not provided, the original workshop abstracts have been included. By organizing this workshop and assembling this volume, our aim is to provide a global perspective on the science of warm-slab subduction, to thereby advance our understanding of internal slab processes and to use this understanding to improve appraisals of the hazards associated with large intraslab earthquakes in the Cascadia system. These events have been the most frequent and damaging earthquakes in western Washington State over the last century. As if to underscore this fact, just six months after this workshop was held, the magnitude 6.8 Nisqually earthquake occurred on February 28th, 2001 at a depth of about 55 km in the Juan de Fuca slab beneath the southern Puget Sound region of western Washington. The Governor’s Office of the State of Washington estimated damage at more than US$2 billion, making it among the costliest earthquakes in U.S. history.

California, Oregon, Washington↗
USGS2016

Groundwater quality in the Lake Champlain and Susquehanna River basins, New York, 2014

In a study conducted by the U.S. Geological Survey in cooperation with the New York State Department of Environmental Conservation, groundwater samples were collected from 6 production wells and 7 domestic wells in the Lake Champlain Basin and from 11 production wells and 9 domestic wells in the Susquehanna River Basin in New York. All samples were collected from June through December 2014 to characterize groundwater quality in these basins. The samples were collected and processed using standard procedures of the U.S. Geological Survey and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds, radionuclides, and indicator bacteria. The Lake Champlain Basin study area covers the 3,050 square miles of the basin in northeastern New York; the remaining part of the basin is in Vermont and Canada. Of the 13 wells sampled in the Lake Champlain Basin, 6 are completed in sand and gravel, and 7 are completed in bedrock. Groundwater in the Lake Champlain Basin was generally of good quality, although properties and concentrations of some constituents— fluoride, iron, manganese, dissolved solids, sodium, radon-222, total coliform bacteria, fecal coliform bacteria, and Escherichia coli bacteria—sometimes equaled or exceeded primary, secondary, or proposed drinking-water standards. The constituent most frequently detected in concentrations exceeding drinking-water standards (5 of 13 samples) was radon-222. The Susquehanna River Basin study area covers the entire 4,522 square miles of the basin in south-central New York; the remaining part of the basin is in Pennsylvania. Of the 20 wells sampled in the Susquehanna River Basin, 11 are completed in sand and gravel, and 9 are completed in bedrock. Groundwater in the Susquehanna River Basin was generally of good quality, although properties and concentrations of some constituents—pH, chloride, sodium, dissolved solids, iron, manganese, aluminum, arsenic, barium, gross-alpha radioactivity, radon-222, methane, total coliform bacteria, and fecal coliform bacteria—sometimes equaled or exceeded primary, secondary, or proposed drinking-water standards. As in the Lake Champlain Basin, the constituent most frequently detected in concentrations exceeding drinking-water standards (13 of 20 samples) was radon-222.

New York↗
USGS2023

Development and application of a risk assessment tool for aquatic invasive species in the international Rainy-Lake of the Woods Basin, United States and Canada

The Rainy-Lake of the Woods Basin covers 70,000 square kilometers in mid-central North America and is contained within the Provinces of Ontario and Manitoba in Canada and the State of Minnesota in the United States. This basin contains natural wilderness areas, national parks, and thousands of lakes that bring outdoor enthusiasts from around the world for hunting, fishing, backpacking, boating, and other forms of recreation. However, trade, commerce, visitors, and wildlife can inadvertently transport hitchhiking exotic invasive species that affect the functioning of natural systems by displacing native organisms, introducing diseases, and modifying predator/prey relations. In cooperation with the International Joint Commission, the U.S. Geological Survey evaluated the aquatic invasive species that pose a possible threat to North America. The outcome of this project is a set of lists of invasive species that have traits amenable or proximity to the Rainy-Lake of the Woods Basin. These lists can be referenced to further evaluate known and potential nonindigenous invasive species. The lists were derived by evaluating more than 1,500 species from several online sources including Non-Indigenous Aquatic Species, Great Lakes Aquatic Nonindigenous Species Information System, Biodiversity Information Serving Our Nation, and other State, Provincial, and Federal lists in the United States and Canada. The purpose of these lists is to be a coarse filter to determine which species pose the greatest risk to the Rainy-Lake of the Woods Basin. Using this filter, seven categories of risk assessment priorities were developed: Very High-Approaching, Very High-Present, High-Approaching, High-Present, Moderate, Low, and Native. These categories can be used by the International Rainy-Lake of the Woods Multi-Agency Arrangement Aquatic Invasive Species Subcommittee to prioritize which species will be evaluated further focusing on five risk factors: arrival risk, vulnerability assessment, ecological impact, socioeconomic impact, and beneficial impact. Based on proximity, ease of transport or introduction, and known impact to Rainy-Lake of the Woods or other impacted ecosystems, this project identified the following 10 species that could be prioritized first for risk evaluations: Bythotrephes longimanus (spiny waterflea), Faxonius rusticus (rusty crayfish), Neogobius melanostomus (round goby), Dreissena polymorpha (zebra mussel), Bithynia tentaculata (mud Bithynia or faucet snail), Potamopyrgus antipodarum (New Zealand mud snail), Butomus umbellatus (flowering rush), Nitellopsis obtusa (starry stonewort), Myriophyllum spicatum (Eurasian watermilfoil), and Phragmites australis australis (common reed).

Open-File Report↗
USGS2010

eMODIS: A User-Friendly Data Source

The U.S. Geological Survey's (USGS) Earth Resources Observation and Science (EROS) Center is generating a suite of products called 'eMODIS' based on Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired by the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS). With a more frequent repeat cycle than Landsat and higher spatial resolutions than the Advanced Very High Resolution Spectroradiometer (AVHRR), MODIS is well suited for vegetation studies. For operational monitoring, however, the benefits of MODIS are counteracted by usability issues with the standard map projection, file format, composite interval, high-latitude 'bow-tie' effects, and production latency. eMODIS responds to a community-specific need for alternatively packaged MODIS data, addressing each of these factors for real-time monitoring and historical trend analysis. eMODIS processes calibrated radiance data (level-1B) acquired by the MODIS sensors on the EOS Terra and Aqua satellites by combining MODIS Land Science Collection 5 Atmospherically Corrected Surface Reflectance production code and USGS EROS MODIS Direct Broadcast System (DBS) software to create surface reflectance and Normalized Difference Vegetation Index (NDVI) products. eMODIS is produced over the continental United States and over Alaska extending into Canada to cover the Yukon River Basin. The 250-meter (m), 500-m, and 1,000-m products are delivered in Geostationary Earth Orbit Tagged Image File Format (Geo- TIFF) and composited in 7-day intervals. eMODIS composites are projected to non-Sinusoidal mapping grids that best suit the geography in their areas of application (see eMODIS Product Description below). For eMODIS products generated over the continental United States (eMODIS CONUS), the Terra (from 2000) and Aqua (from 2002) records are available and continue through present time. eMODIS CONUS also is generated in an expedited process that delivers a 7-day rolling composite, created daily with the most recent 7 days of acquisition, to users monitoring real-time vegetation conditions. eMODIS Alaska is not part of expedited processing, but does cover the Terra mission life (2000-present). A simple file transfer protocol (FTP) distribution site currently is enabled on the Internet for direct download of eMODIS products (ftp://emodisftp.cr.usgs.gov/eMODIS), with plans to expand into an interactive portal environment.

Open-File Report↗
USGS2012

2008 Joint United States-Canadian program to explore the limits of the Extended Continental Shelf aboard the U.S. Coast Guard cutter Healy --Cruise HLY0806

In September 2008, the U.S. Geological Survey (USGS), in cooperation with Natural Resources Canada, Geological Survey of Canada (GSC), conducted bathymetric and geophysical surveys in the Arctic Beaufort Sea aboard the U.S. Coast Guard cutter USCGC Healy . The principal objective of this mission to the high Arctic was to acquire data in support of delineation of the outer limits of the U.S. and Canadian Extended Continental Shelf (ECS) in the Arctic Ocean in accordance with the provisions of Article 76 of the Law of the Sea Convention. The Healy was accompanied by the Canadian Coast Guard icebreaker Louis S. St- Laurent . The science parties on the two vessels consisted principally of staff from the USGS ( Healy ), and the GSC and the Canadian Hydrographic Service ( Louis ). The crew included marine mammal and Native-community observers, ice observers, and biologists conducting research of opportunity in the Arctic Ocean. The joint survey proved an unqualified success. The Healy collected 5,528 km of swath (multibeam) bathymetry (38,806 km 2 ) and CHIRP subbottom profile data, with accompanying marine gravity measurements. The Louis acquired 2,817 km of multichannel seismic (airgun) deep-penetration reflection-profile data along 12 continuous lines, as well as 35 sonobuoy refraction stations and accompanying single-beam bathymetry. The coordinated efforts of the two vessels resulted in seismic-reflection profile data of much higher quality and continuity than if the data had been acquired with a single vessel alone. Equipment failure rate of the seismic equipment gear aboard the Louis was greatly improved with the advantage of having a leading icebreaker. When ice conditions proved too severe to deploy the seismic system, the Louis led the Healy , resulting in much improved quality of the swath bathymetry and CHIRP sub-bottom data in comparison with data collected by the Healy in the lead or working alone. Ancillary science objectives, including ice observations, deployment of ice-monitoring buoys and water-column sampling for biologic (phytoplankton) studies, were also successfully accomplished.

Open-File Report↗
USGS2002

Average altitude of the water table (1990-99) and frequency analysis of water levels (1974-99) in the Biscayne aquifer, Miami-Dade County, Florida

Miami-Dade County occupies about 2,000 square miles along the southeastern part of peninsular Florida. Five prominent physiographic features are located within the confines of Miami-Dade County and include the Atlantic Coastal Ridge, Big Cypress Swamp, the Sandy Flatlands, coastal marshes and mangrove swamps, and the Everglades (fig. 1). The highest altitudes occur along the Atlantic Coastal Ridge (2 to 10 miles wide), ranging from 8 to 15 feet above sea level but may be as high as 20 feet. The Atlantic Coastal Ridge forms a natural barrier to drainage from the interior. The Sandy Flatlands in northeastern Miami-Dade County ranges from 6 to 18 feet above sea level; this area was poorly drained prior to development. The Everglades forms a natural trough across the county, with altitudes ranging from 9 feet above sea level in the northwestern part to about 3 feet above sea level in the southwestern part. A small section of the Big Cypress Swamp occupies northwestern Miami-Dade County, with altitudes ranging from 7 to 10 feet above sea level. Along the coast, marshes and mangrove swamps have altitudes ranging from 0 to 3 feet above sea level (Fish and Stewart, 1991). The U.S. Geological Survey (USGS), in cooperation with the Miami-Dade County Department of Environmental Resources Management (DERM), conducted a study to determine the average altitude of the water table in the Biscayne aquifer in Miami-Dade County and to perform a water-level frequency analysis for selected time periods. Water-table maps in this report are based on average yearly May, October, high, and low water levels during 1990-94, 1995-99, and 1990-99. Data collected in May and October are used to show the yearly water-level conditions at the end of the dry and wet seasons, respectively. Water-level frequency analysis maps (5-, 10-, and 25-year recurrence water levels) in this report are based on analysis of water-level data from continuous water-level recorders for the 1974-99 period. Water-level data for the maps were collected by Everglades National Park (ENP), the USGS, and the South Florida Water Management District (SFWMD). Data for ENP sites were provided as averages by ENP. Determination of averages for the USGS data was performed using options available in the USGS Automated Data Processing System (ADAPS), and averages for the SFWMD data were determined from options available in the SFWMD Hydrometeorologic and Water-Quality Database (DBHYDRO). The ENP, USGS, and SFWMD data are reported as mean daily water levels and are referenced to sea level. In this report, sea level refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)-a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929. In this report, horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Florida↗
USGS2026

Sampling and analysis plan for the water-quality monitoring program in Lake Koocanusa and upper Kootenai River, Montana, water years 2022–23

The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected water-quality samples and environmental data in Lake Koocanusa (also known as “Koocanusa Reservoir”), the Kootenai River, and the Tobacco River during water years 2022–23. The transboundary Lake Koocanusa is in southeastern British Columbia, Canada, and northwestern Montana, United States. It was formed by constructing Libby Dam on the Kootenai River 26 kilometers upstream from Libby, Montana. One of the lake sites and the Kootenai River site, in the Libby Dam tailwater (the outflow of the lake flow into the Kootenai River), were equipped with automated, high-frequency ServoSipper water samplers. At the lake site, these samplers were mounted to pontoon platforms during the summer, and a submersible ServoSipper sipper was deployed with ice buoys during the winter. Samples were automatically collected from multiple depths. At the Kootenai River site, these samplers were housed in the gage house. In water year 2022, discrete water-quality samples were collected every 4–6 weeks, year round, at all four lake sites in the Kootenai River between April and November. In water year 2023, discrete water-quality samples were collected at three lake sites and the Kootenai and Tobacco River sites every 4–6 weeks. The goal of this project was to collect multidepth, high-frequency vertical and temporal water-quality samples and data to understand the limnological and biological processes that control variations and trends in selenium concentrations and loads throughout Lake Koocanusa and in the Libby Dam tailwater at the southern end of the lake. This sampling and analysis plan documents the organization, sampling and data-collection scheme and design, pre- and post-collection processes, and quality-assurance and quality-control procedures of the Koocanusa/Kootenai water-quality monitoring program during water years 2022–23.

Montana↗
USGS2013

Distribution of late Pleistocene ice-rich syngenetic permafrost of the Yedoma Suite in east and central Siberia, Russia

This digital database is the product of collaboration between the U.S. Geological Survey, the Geophysical Institute at the University of Alaska, Fairbanks; the Los Altos Hills Foothill College GeoSpatial Technology Certificate Program; the Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany; and the Institute of Physical Chemical and Biological Problems in Soil Science of the Russian Academy of Sciences. The primary goal for creating this digital database is to enhance current estimates of soil organic carbon stored in deep permafrost, in particular the late Pleistocene syngenetic ice-rich permafrost deposits of the Yedoma Suite. Previous studies estimated that Yedoma deposits cover about 1 million square kilometers of a large region in central and eastern Siberia, but these estimates generally are based on maps with scales smaller than 1:10,000,000. Taking into account this large area, it was estimated that Yedoma may store as much as 500 petagrams of soil organic carbon, a large part of which is vulnerable to thaw and mobilization from thermokarst and erosion. To refine assessments of the spatial distribution of Yedoma deposits, we digitized 11 Russian Quaternary geologic maps. Our study focused on extracting geologic units interpreted by us as late Pleistocene ice-rich syngenetic Yedoma deposits based on lithology, ground ice conditions, stratigraphy, and geomorphological and spatial association. These Yedoma units then were merged into a single data layer across map tiles. The spatial database provides a useful update of the spatial distribution of this deposit for an approximately 2.32 million square kilometers land area in Siberia that will (1) serve as a core database for future refinements of Yedoma distribution in additional regions, and (2) provide a starting point to revise the size of deep but thaw-vulnerable permafrost carbon pools in the Arctic based on surface geology and the distribution of cryolithofacies types at high spatial resolution. However, we recognize that the extent of Yedoma deposits presented in this database is not complete for a global assessment, because Yedoma deposits also occur in the Taymyr lowlands and Chukotka, and in parts of Alaska and northwestern Canada.

Siberia↗
USGS2002

Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001

We present isoseismal maps, macroseismic intensities, and community summaries of damage for the MW=6.8 Nisqually, Washington, earthquake of 28 February, 2001. For many communities, two types of macroseismic intensity are assigned, the traditional U.S. Geological Survey Modified Mercalli Intensities (USGS MMI) and a type of intensity newly introduced with this paper, the USGS Reviewed Community Internet Intensity (RCII). For most communities, the RCII is a reviewed version of the Community Internet Intensity (CII) of Wald and others (1999). For some communities, RCII is assigned from such non-CII sources as press reports, engineering reports, and field reconnaissance observations. We summarize differences between procedures used to assign RCII and USGS MMI, and we show that the two types of intensity are nonetheless very similar for the Nisqually earthquake. We do not see evidence for systematic differences between RCII and USGS MMI that would approach one intensity unit, at any level of shaking, but we document a tendency for the RCII to be slightly lower than MMI in regions of low intensity and slightly higher than MMI in regions of high intensity. The highest RCII calculated for the Nisqually earthquake is 7.6, calculated for zip code 98134, which includes the ?south of downtown? (Sodo) area of Seattle and Harbor Island. By comparison, we assigned a traditional USGS MMI 8 to the Sodo area of Seattle. In all, RCII of 6.5 and higher were assigned to 58 zip-code regions. At the lowest intensities, the Nisqually earthquake was felt over an area of approximately 350,000 square km (approximately 135,000 square miles) in Washington, Oregon, Idaho, Montana, and southern British Columbia, Canada. On the basis of macroseismic effects, we infer that shaking in the southern Puget Sound region was somewhat less for the 2001 Nisqually earthquake than for the Puget Sound earthquake of April 13, 1949, which had nearly the same hypocenter and magnitude. Allowing for differences in hypocenter, shaking in the 2001 earthquake was very similar to that produced by the Puget Sound earthquake of April 25, 1965. First-person accounts of the effects of the 2001 earthquake on individual households are given for some communities.

Open-File Report↗
USGS2013

2010 Joint United States-Canadian Program to explore the limits of the Extended Continental Shelf aboard U.S. Coast Guard Cutter Healy--Cruise HLY1002

In August and September 2010, the U.S. Geological Survey, in cooperation with Natural Resources Canada, Geological Survey of Canada, conducted bathymetric and geophysical surveys in the Beaufort Sea and eastern Arctic Ocean aboard the U.S. Coast Guard Cutter Healy. The principal objective of this mission to the high Arctic was to acquire data in support of a delineation of the outer limits of the U.S. and Canadian Extended Continental Shelf in the Arctic Ocean, in accordance with the provisions of Article 76 of the United Nations Convention on the Law of the Sea. The Healy was accompanied by the Canadian Coast Guard icebreaker Louis S. St-Laurent. The scientific parties on board the two vessels consisted principally of staff from the U.S. Geological Survey (Healy), and the Geological Survey of Canada and the Canadian Hydrographic Service (Louis). The crew also included marine-mammal observers, Native-community observers, ice observers, and biologists conducting research of opportunity in the Arctic Ocean. Despite interruptions necessitated by three medical emergencies, the joint survey proved largely successful. The Healy collected 7,201 trackline-kilometers of swath (multibeam) bathymetry (47,663 square kilometers) and CHIRP subbottom data, with accompanying marine gravity measurements, and expendable bathythermograph data. The Louis acquired 3,673 trackline-kilometers of multichannel seismic (airgun) deep-penetration reflection data along 25 continuous profiles, as well as 34 sonobuoy refraction stations and 9,500 trackline-kilometers of single-beam bathymetry. The coordinated efforts of the two vessels resulted in seismic-reflection-profile data that were of much higher quality and continuity than if the data had been acquired with a single vessel alone. The equipment-failure rate of the seismic equipment aboard the Louis was greatly reduced when the Healy led as the ice breaker. When ice conditions proved too severe to deploy the seismic system, the Louis led the Healy, resulting in much improved quality of the swath bathymetric and CHIRP subbottom data in comparison with data collected either by the Healy in the lead or the Healy working alone. During periods when the Healy was operating alone (principally when the Louis was diverted for emergency medical evacuations or ship repairs), the Healy was able to deploy a piston-core-sampler (10 meters maximum potential recovery depending on configuration). The coring operations resulted in recovery of cores at five locations ranging from 2.4 to 5.7 meters in length from water depths ranging from 1,157 to 3,700 meters. One of these cores sited on the Alaskan margin recovered the first reported occurrence of methane hydrate from the Arctic Ocean. Ancillary science objectives, including ice observations and deployment of ice-monitoring buoys and water-column sampling to measure acidification of Arctic waters were successfully conducted. The water-column sampling included using 10 full-ocean-depth, water-sampling casts with accompanying conductivity-temperature-depth measurements. Except for the data deemed proprietary, data from the cruise have been archived and are available for download at the National Geophysical Data Center and at cooperating organizations. Outreach staff and guest teachers aboard the two vessels provided near-real-time connection between the research activities and the public through online blogs, web pages, and other media.

Open-File Report↗