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USGS1962

Ground-water provinces of Brazil

As part of a study of the status of investigations and development of ground water in Brazil, made under the auspices of the United States International Cooperation Administration and with the cooperation of the Government of Brazil, the country was divided into seven ground-water provinces. The identification and delineation of the provinces were based on the regional distribution of the dominant geologic units which are known or inferred to have distinctive water-bearing characteristics. Three of the provinces, covering most of the country, are underlain by Precambrian crystalline rocks. Three others coincide in part with four extensive sedimentary basins--the Parnaiba or Maranhfio basin and the contiguous Sao Francisco basin in the northeast and east, the Amazon basin in the north and northwest, and the Paranfi basin in the south and southwest. In addition, the narrow, discontinuous coastal plain is considered as a province. the occurrence of ground water is discussed briefly, and pertinent data are given on the more important aquifers, together with information on some existing wells. Because of the widespread distribution of crystalline rocks of low permeability, it is difficult in many areas to develop large or even adequate ground-water supplies. In general, satisfactory supplies of water are available in most of the rest of the country. Some problems include the relative deficiency of rainfall in the northeast together with the occurrence, in parts of this region, of mineralized water in the crystalline rocks. Also, there is a potential problem of excessive lowering of water levels and interference among wells in the intensively developed area of the city of Sao Paulo.

Water Supply Paper↗

USGS2011

Construction of shipping channels in the Detroit River: History and environmental consequences

The Detroit River is one of the most biologically diverse areas in the Great Lakes basin. It has been an important international shipping route since the 1820s and is one of the busiest navigation centers in the United States. Historically, it supported one of the most profitable Lake Whitefish (Coregonus clupeaformis) commercial fisheries in the Great Lakes. Since 1874, the lower Detroit River has been systematically and extensively modified, by construction of deepwater channels, to facilitate commercial shipping. Large-scale dredging, disposal of dredge spoils, and construction of water-level compensating works has greatly altered channel morphology and flow dynamics of the river, disrupting ecological function and fishery productivity of the river and influencing Great Lakes water levels. From 1874 to 1968, major construction projects created 96.5 kilometers (60 miles) of shipping channels, removed over 46,200,000 m 3 of material, covered 4,050 hectares (40.5 square kilometers) of river bottom with dredge spoils, and built 85 hectares of above-waterline compensating works at a total cost of US$283 million. Interest by industries and government agencies to develop the river further for shipping is high and increasing. Historically, as environmental protection agencies were created, construction impacts on natural resources were increasingly addressed during the planning process and, in some cases, assessments of these impacts greatly altered or halted proposed construction projects. Careful planning of future shipping-channel construction and maintenance projects, including a thorough analysis of the expected environmental impacts, could greatly reduce financial costs and ecological damages as compared to past shipping-channel construction projects.

Michigan↗

USGS2022

The global seismographic network reveals atmospherically coupled normal modes excited by the 2022 Hunga Tonga eruption

The eruption of the submarine Hunga Tonga-Hunga Haʻapai (Hunga Tonga) volcano on 15 January 2022, was one of the largest volcanic explosions recorded by modern geophysical instrumentation. The eruption was notable for the broad range of atmospheric wave phenomena it generated and for their unusual coupling with the oceans and solid Earth. The event was recorded worldwide across the Global Seismographic Network (GSN) by seismometers, microbarographs and infrasound sensors. The broad-band instrumentation in the GSN allows us to make high fidelity observations of spheroidal solid Earth normal modes from this event at frequencies near 3.7 and 4.4 mHz. Similar normal mode excitations were reported following the 1991 Pinatubo (Volcanic Explosivity Index of 6) eruption and were predicted, by theory, to arise from the excitation of mesosphere-scale acoustic modes of the atmosphere coupling with the solid Earth. Here, we compare observations for the Hunga Tonga and Pinatubo eruptions and find that both strongly excited the solid Earth normal mode 0 S 29 (3.72 mHz). However, the mean modal amplitude was roughly 11 times larger for the 2022 Hunga Tonga eruption. Estimates of attenuation ( Q ) for 0 S 29 across the GSN from temporal modal decay give Q = 332 ± 101, which is higher than estimates of Q for this mode using earthquake data ( Q = 186.9 ± 5). Two microbarographs located at regional distances (<1000 km) to the volcano provide direct observations of the fundamental acoustic mode of the atmosphere. These pressure oscillations, first observed approximately 40 min after the onset of the eruption, are in phase with the seismic Rayleigh wave excitation and are recorded only by microbarographs in proximity (<1500 km) to the eruption. We infer that excitation of fundamental atmospheric modes occurs within a limited area close to the site of the eruption, where they excite select solid Earth fundamental spheroidal modes of similar frequencies that are globally recorded and have a higher apparent Q due to the extended duration of atmospheric oscillations.

Geophysical Journal International↗

USGS2005

Population status of Kittlitz's Murrelet Brachyramphus brevirostris along the southern coast of the Alaska Peninsula

The Kittlitz's murrelet ( Brachyramphus brevirostris ) is a rare seabird that nests in alpine terrain and generally forages near tidewater glaciers during the breeding season. An estimated 95% of the global population breeds in Alaska, with some unknown proportion breeding in the Russian Far East. A global population estimate using bestavailable data in the early 1990s was 20,000 individuals. However, recent survey data from two core areas (Prince William Sound and Glacier Bay) suggest that populations have declined by 75-90% during the past 10-20 years. In response to these declines, a coalition of environmental groups petitioned the USFWS in May 2001 to list the Kittlitz’s murrelet under the Endangered Species Act (ESA), and in 2004 Kittlitz’s Murrelet was declared a candidate species under the ESA. In 2005, BirdLife International classified the species as “critically endangered”. In 2002, we began a three-year project to examine population status and trend of Kittlitz’s Murrelets in areas where distribution and abundance were poorly known. Results from the 2002 field season, focused on the south coast of the Kenai Peninsula, suggested that the local population of Kittlitz’s Murrelets has declined by ca. 74% since 1986, with a current population of ca. 500 individuals. Here we present results from the 2003 field season when we surveyed Kittlitz’s Murrelets along the southern coast of the Alaska Peninsula. This is a large region that encompasses a substantial portion of the known range of the Kittlitz’s Murrelet, yet has never been surveyed rigorously for murrelets or any other non-colonial marine birds. During four weeks of surveys, we established a set of nearshore and offshore transects (over 825 linear kilometers in total) with a stratified sample design, combining random and systematically selected transects. From a total of 123 individuals seen on transects, we estimate a total population of 2265 (95% CI 1165-4405) Kittlitz’s Murrelets along the south coast of the Alaska Peninsula. For comparison, we estimate the population size of the congeneric Marbled Murrelet ( Brachyramphus marmoratus ). We discuss broad-scale murrelet habitat relationships and species comparisons, and present recommendations for management and future work. Other species of marine birds and mammals were also surveyed; summarized information is included as an appendix.

Alaska↗

USGS2020

A not so sudden impact—Historical relations between conifers and insects can help predict damage by nonnative insects

The arrival and establishment of nonnative insects in North America is increasingly problematic. International trade has created opportunities to move wood products and nursery stock worldwide, which has increased the risk of insect introduction to regions or countries where they are not native. One group of researchers, the High-impact Insect Invasions Working Group (HIIWG), has developed a predictive model that can be used to estimate the likelihood that a newly arriving nonnative insect may significantly impact North American conifers. The HIIWG examined several traits and factors associated with nonnative insects feeding on conifers (a conifer specialist) already established in North America. Using these data, the HIIWG identified which combination of factors best predicted the risk that a conifer specialist would have a high impact. The researchers then developed a statistical model to predict the probability that a conifer specialist yet to arrive in North America would cause significant damage to conifers if the insect became established. Using three factors, the model calculates the odds of any particular conifer specialist having a high impact on a North American conifer in a range between 1 in 6.5 to 1 in 2,858. This model is a valuable tool to help identify invading insects with the potential to be the most damaging if the insect becomes established in North America. In addition, application of tools like this model can increase positive environmental outcomes for land managers by focusing their efforts on conifer populations that are deemed most vulnerable to extensive mortality

Fact Sheet↗

USGS2022

Selenium in the Kootenai River Basin, Montana and Idaho, United States, and British Columbia, Canada

Selenium entering the 90-mile long transboundary Koocanusa Reservoir (also called Lake Koocanusa) in southeastern British Columbia, Canada, and northwestern Montana, United States, has been measured at concentrations above State and Federal water-quality and aquatic life standards. The reservoir is within the international Kootenai (or “Kootenay” in Canada) drainage basin, which contains critical habitat for native fish species and is impounded by Libby Dam 16 miles upstream from Libby, Montana. Since 1984, selenium concentrations have ranged from below detection to greater than 8 micrograms per liter in the Elk River, measured 2.2 miles above its discharge into Koocanusa Reservoir at a British Columbia environmental monitoring station (site 0200016). Selenium is a required micro-nutrient, but elevated concentrations in water bioaccumulate in egg-laying fish and birds, causing various sublethal effects and death. One possible source of selenium in the Kootenai River Basin is the excavation of bedrock in the Elk River Valley to access coal seams for metallurgical steelmaking and coal production. Five open-pit coal mines are operating in this region of southeastern British Columbia that produce about 21 million tons of metallurgical coal annually. Site-specific selenium standards were established for the reservoir in 2020 following collaborative work by the U.S. Geological Survey, Montana Department of Environmental Quality, the British Columbia Ministry of Environment and Climate Change Strategy, the Lake Koocanusa Monitoring and Research Working Group, and the Selenium Technical Subcommittee. The standards of 0.8 microgram per liter for dissolved selenium in the water column and 15.1 milligrams per kilogram dry weight for fish egg (ovary) tissue (in addition to the muscle and wholebody standards) were adopted into Montana State law in 2020 and approved by the U.S. Environmental Protection Agency in 2021.

British Columbia, Idaho, Montana↗

USGS1953

Geology, of the High Climb Pegmatite, Custer County, South Dakota

The High Climb pegmatite, Custer County, S. Dak., belongs to the series of pegmatitic and granitic rocks that characterize the Harney Peak region of the southern Black Hills. It intrudes pre-Cambrian metamorphic rocks consisting chiefly of quartz-mica schist. The country rock has been altered to a tourmaline-rich schist along part of the pegmatite contact. The structure of the pegmatite, in general is concordant with the westward-dipping schistosity of the country rock, but locally the pegmatite is crosscutting. The main part of the pegmatite is an irregularly shaped pipe that plunges 45° N. 40° W., parallel to the average plunge of rolls in the foot wall. A small northern extension of the pegmatite has a lenticular shape and crosscuts the schist at a low angle. Rolls in this part of the pegmatite have an average plunge of 28° N. 25° W. One large, north-trending crestal roll divides the outcrop of the northern segment of the pegmatite into two parts. The pegmatite has a well- defined internal structure consisting of five zones. A fine-grained wall zone, consisting of albite-quartz pegmatite, and a medium-grained first intermediate zone, consisting of albite-quartz-muscovite pegmatite, form incomplete concentric shells. Perthite-quartz-albite pegmatite (second intermediate zone) forms a hood-shaped unit between the outer units and the third intermediate zone along the crest and hanging-wall of the pegmatite. A concentric shell of quartz-cleavelandite pegmatite (third intermediate zone) surrounds a lenticular core of quartz pegmatite that contains altered spodumene, in addition -to the five zones, a fracture-filling unit of quartz-perthite-muscovite-albite-pegmatite and a possible sixth zone (or replacement unit?) of very fine-grained muscovite pegmatite were recognized. The essential minerals of the pegmatite include microcline-perthite, quartz, albite, and muscovite. Accessory minerals include tourmaline, beryl, amblygonite (variety, montebrasite), apatite, columbite-tantalite, loellingite, altered spodumene, numerous unidentified dark-colored phosphate minerals, a manganese-bearing carbonate, garnet, and chalcopyrite. An explanation of the origin of the pegmatite requires fractional crystallization and incomplete reaction in a restricted system. The concentric zonal structure and the general increase in grain size from the wall zone to the core suggest that the pegmatite units crystallized in order from the walls inward, without any true replacement stages. Industrial minerals that have been produced at the High Climb pegmatite are beryl, amblygonite, potash feldspar, columbite-tantalite, scrap mica, and sheet mica.

South Dakota↗

USGS1984

Measured sections and discussion of the main turbidite member, Middle Pennsylvanian Minturn Formation, northern Sangre de Cristo Range, Custer and Saguache counties, Colorado

Turbidites are sediments deposited by turbid density currents. The turbidites described here are interpreted as prodelta deposits that formed in front of fan deltas and alluvial fans during the uplift of the ancestral Rocky Mountains in Pennsylvanian time. Laterally extensive, lenticular sand bodies deposited by turbidity flows crop out in the Middle Pennsylvanian Minturn Formation in the northern Sangre de Crísto Range, Custer and Saguache Counties, Colo. (figs. 1, 2). One of the turbidite-bearing intervals, informally designated the "main turbidite member," lies 90.6 m above the base of the Minturn; it reaches 150 m in thickness and extends more than 13 km along strike. The internal stratigraphy and sedimentary structures of the main turbidite member are described from the measured sections presented here. The Middle Pennsylvanian Minturn Formation of the Spread Eagle Peak thrust plate (Lindsey, Johnson, and Andriessen, 1983) consists of about 2,000 m of interbedded conglomeratic sandstone, sandstone, siltstone, and lesser amounts of conglomerate, shale, and limestone. The lower 1,500 m of the Minturn is composed mainly of prograding deltaic-alluvial cycles that contain interva1s of prodelta turbidites. The upper 500 m of the Minturn consists of deposits of small deltas and bralded streams interbedded with shallow marine limestones Interpreted as a san-delta deposit (Clark, 1982). Above the Minturn Formation, the Pennsylvanian and Permian Sangre de Cristo Formation consists of more than 1,700 m of coarse conglomerate and sandstone interpreted as an a 11uvialfan deposit (Lindsey and Schaefer, 1984). The main turbidite member is the thickest and most extensive of the intervals of prodelta turbidites in the Minturn Formation. Each turbidite interval is part of a coarsening upward sequence interpreted as a prograding fan delta. A typical prograding cycle consists of prodelta marine shale and siltstone, prodelta turbidite sandstones, delta-front sandstone and conglomerate, and deltaic and alluvial-plain sandstone, siltstone, and shale. Fossils of 1and plants (mostly Calamites, including some in growth position) are locally abundant in deltaic and alluvial sediments of the prograding cycles. The turbidites are regarded as having been deposited offshore from alluvial systems.

Colorado↗

USGS2008

Geomorphic map of Worcester County, Maryland, interpreted from a LIDAR-based, digital elevation model

A recently compiled mosaic of a LIDAR-based digital elevation model (DEM) is presented with geomorphic analysis of new macro-topographic details. The geologic framework of the surficial and near surface late Cenozoic deposits of the central uplands, Pocomoke River valley, and the Atlantic Coast includes Cenozoic to recent sediments from fluvial, estuarine, and littoral depositional environments. Extensive Pleistocene (cold climate) sandy dune fields are deposited over much of the terraced landscape. The macro details from the LIDAR image reveal 2 meter-scale resolution of details of the shapes of individual dunes, and fields of translocated sand sheets. Most terrace surfaces are overprinted with circular to elliptical rimmed basins that represent complex histories of ephemeral ponds that were formed, drained, and overprinted by younger basins. The terrains of composite ephemeral ponds and the dune fields are inter-shingled at their margins indicating contemporaneous erosion, deposition, and re-arrangement and possible internal deformation of the surficial deposits. The aggregate of these landform details and their deposits are interpreted as the products of arid, cold climate processes that were common to the mid-Atlantic region during the Last Glacial Maximum. In the Pocomoke valley and its larger tributaries, erosional remnants of sandy flood plains with anastomosing channels indicate the dynamics of former hydrology and sediment load of the watershed that prevailed at the end of the Pleistocene. As the climate warmed and precipitation increased during the transition from late Pleistocene to Holocene, dune fields were stabilized by vegetation, and the stream discharge increased. The increased discharge and greater local relief of streams graded to lower sea levels stimulated down cutting and created the deeply incised valleys out onto the continental shelf. These incised valleys have been filling with fluvial to intertidal deposits that record the rising sea level and warmer, more humid climate in the mid-Atlantic region throughout the Holocene. Thus, the geomorphic details provided by the new LIDAR DEM actually record the response of the landscape to abrupt climate change. Holocene trends and land-use patterns from Colonial to modern times can also be interpreted from the local macro- scale details of the landscape. Beyond the obvious utility of these data for land-use planning and assessments of resources and hazards, the new map presents new details on the impact of climate changes on a mid-latitude, outer Coastal plain landscape.

Maryland↗

USGS2023

Documenting Arctic sea ice dynamics with Global Fiducials Program imagery

For more than 25 years, the U.S. Geological Survey (USGS) has used the remote-sensing capabilities of United States National Imagery Systems (USNIS) to obtain high-resolution electro-optical imagery to monitor Earth’s response to global environmental change. A major focus has been monitoring sea ice behavior in the Arctic Ocean and its marginal seas. In 1997 and 1998, under the direction of the Global Fiducials Program (GFP), USNIS imagery was collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) Project. In 1999, collection of USNIS imagery of six static sea ice sites in the Arctic Ocean and its marginal seas began, and the imagery was archived in the USGS-hosted Global Fiducials Library (GFL). The static sites were imaged through 2014, creating time series of geographically referenced images which scientists have used to study seasonal changes in Arctic ice over the same locations for extended time periods. In early 2009, the Central Intelligence Agency’s MEDEA Program requested that the USGS use USNIS imagery to track movements of sea ice floes during an entire Arctic summer (April through September). The goal was to improve researchers’ understanding of seasonal changes in Arctic sea ice. In order to track and repeatedly capture imagery of the same ice as it drifted across the Arctic Ocean, the USGS developed a methodology and a series of protocols to use data from telemetering drift buoys deployed at locations across the Arctic Ocean by the International Arctic Buoy Programme (IABP) to track the drift of targeted ice masses for periods that exceeded a year. Resulting time series of sea ice imagery, captured while monitoring 38 individual buoys, were archived in the GFL. In 2013 and 2014, in support of the Seasonal Ice Zone Reconnaissance Surveys (SIZRS) Program led by the University of Washington, Seattle, Washington, the USGS requested the collection of USNIS imagery of selected sites in the Beaufort and Chukchi Seas located at every degree of latitude between 70º and 80º N. along a north-south transect. This was done to track and understand the interplay among the ice, atmosphere, and ocean and what it contributes to the rapid decline in summer ice extent that has occurred in recent years. Under the auspices of the GFP, thousands of sea ice images have been collected. Many of those that pass a quality and cloud-cover screening are archived in the GFL. Of these, more than 1,750 sea ice images have been publicly released, following an editing and processing procedure that produces high-resolution degraded images, known as “literal imagery-derived products” or LIDPs. These LIDPs have been approved for free, unrestricted public distribution and scientific analysis. The LIDPs can be downloaded from the USGS Global Fiducials Library Data Access Portal (USGS GFLDAP) at https://www.usgs.gov/global-fiducials-library-data-access-portal . In addition, nonliteral imagery-derived products (nonliteral IDPs), such as metadata, maps, charts, and graphs, have also been released.

Open-File Report↗

USGS2002

Flood-hazard mapping in Honduras in response to Hurricane Mitch

The devastation in Honduras due to flooding from Hurricane Mitch in 1998 prompted the U.S. Agency for International Development, through the U.S. Geological Survey, to develop a country-wide systematic approach of flood-hazard mapping and a demonstration of the method at selected sites as part of a reconstruction effort. The design discharge chosen for flood-hazard mapping was the flood with an average return interval of 50 years, and this selection was based on discussions with the U.S. Agency for International Development and the Honduran Public Works and Transportation Ministry. A regression equation for estimating the 50-year flood discharge using drainage area and annual precipitation as the explanatory variables was developed, based on data from 34 long-term gaging sites. This equation, which has a standard error of prediction of 71.3 percent, was used in a geographic information system to estimate the 50-year flood discharge at any location for any river in the country. The flood-hazard mapping method was demonstrated at 15 selected municipalities. High-resolution digital-elevation models of the floodplain were obtained using an airborne laser-terrain mapping system. Field verification of the digital elevation models showed that the digital-elevation models had mean absolute errors ranging from -0.57 to 0.14 meter in the vertical dimension. From these models, water-surface elevation cross sections were obtained and used in a numerical, one-dimensional, steady-flow stepbackwater model to estimate water-surface profiles corresponding to the 50-year flood discharge. From these water-surface profiles, maps of area and depth of inundation were created at the 13 of the 15 selected municipalities. At La Lima only, the area and depth of inundation of the channel capacity in the city was mapped. At Santa Rose de Aguan, no numerical model was created. The 50-year flood and the maps of area and depth of inundation are based on the estimated 50-year storm tide.

Water-Resources Investigations Report↗

USGS2024

Near-real-time earthquake-induced fatality estimation using crowdsourced data and few-shot large-language models

When a damaging earthquake occurs, immediate information about casualties (e.g., fatalities and injuries) is critical for time-sensitive decision-making by emergency response and aid agencies in the first hours and days. Systems such as the Prompt Assessment of Global Earthquakes for Response (PAGER) by the U.S. Geological Survey (USGS) were developed to provide a forecast of such impacts within about 30 min of any significant earthquake globally. However, existing disaster-induced human loss estimation systems often rely on early casualty reports manually retrieved from global traditional media, which are labor-intensive, time-consuming, and have significant time latencies. Recent approaches use keyword matching and topic modeling to identify human casualty-relevant information from social media but tend to be error-prone when dealing with complex semantics in multi-lingual text data and parsing dynamically changing and conflicting human death and injury numbers shared by various unvetted sources in social media platforms. In this work, we introduce an end-to-end framework to significantly improve the timeliness and accuracy of global earthquake-induced human loss forecasting using multi-lingual, crowdsourced social media. Our framework integrates (i) a hierarchical casualty extraction model built upon large language models, prompt design, and few-shot learning to retrieve quantitative human loss claims from social media, (ii) a physical constraint-aware, dynamic-truth discovery model that discovers the truthful human loss from massive noisy and potentially conflicting human loss claims, and (iii) a Bayesian updating loss projection model that dynamically updates the final loss estimation using discovered truths. We test the framework in real-time on a series of global earthquake events in 2021 and 2022 and show that our framework effectively automates the retrieval of casualty information faster but with comparable accuracy to those now retrieved manually by the USGS. The code associated with this work is made available at: https://github.com/SusuXu-s-Lab/Hierarchical-Earthquake-Casualty-Information-Retrieval

International Journal of Disaster Risk Reduction↗

USGS2000

Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

A 6-year (1990-96) study of the Ellison Park wetland, a 423-acre, predominantly cattail ( Typha glauca ) marsh in Monroe County, N.Y., was conducted to document the effect that this wetland has on the water quality of Irondequoit Creek, which flows through it. Irondequoit Creek drains 151 square miles of mostly urban and suburban land and is the main tributary to Irondequoit Bay on Lake Ontario. The wetland was a sink for total phosphorus and total suspended solids (28 and 47 percent removal efficiencies, respectively, over the 6-year study period). Sedimentation and vegetative filtration appear to be the primary mechanisms for the decrease in loads of these constituents. Total nitrogen loads were decreased slightly by the wetland; removal efficiencies for ammonia-plus-organic nitrogen and nitrate-plus-nitrite were 6 and 3 percent, respectively. The proportions of total phosphorus and total nitrogen constituents were altered by the wetland. Orthophosphate and ammonia nitrogen were generated within the wetland and represented 12 percent of the total phosphorus output load and 1.8 percent of total nitrogen output load, respectively. Conservative chemicals, such as chloride and sulfate, were littleaffected by the wetland. Concentrations of zinc, lead, and cadmium showed statistically significant decreases, which are attributed to sedimentation and filtration of sediment and organic matter to which these elements adsorb. Sediment samples from open-water depositional areas in the wetland contained high concentrations of (1) trace metals, including barium, manganese, strontium, zinc (each of which exceeded 200 parts per million), as well as chromium, copper, lead, and vanadium, and (2) some polycyclic aromatic hydrocarbons. Persistent organochlorine pesticides, such as chlordane, dieldrin, DDT and its degradation products (DDD and DDE), and polychlorinated biphenyls (PCB's), also were detected, but concentrations of these compounds were within the ranges often found in depositional environments in highly urbanized areas. Cattail shoots attained a maximum height of 350 centimeters, a density of more than 30 shoots per square meter, and total biomass of more than 5,600 grams per square meter (46 percent of which was in above-ground tissues during the growing season). Nitrogen and potassium were three times more abundant in above-ground tissues (2.4 and 1.5 percent by dry weight, respectively) than in below-ground tissues (0.8 and 0.5 percent, respectively). Concentrations of phosphorus, molybdenum, and manganese in above-ground tissues were similar to those in below-ground tissues, but the concentrations of all other constituents were considerably higher in below-ground tissues. Concentrations of several elements exceeded those typically found in natural wetlands; these included manganese (417 ppm, parts per million) and sodium (3,600 ppm) in above-ground tissues, and aluminum (1,540 ppm), iron (15,400 ppm), manganese (433 ppm), and sodium (10,000 ppm) in below-ground tissues. Large quantities of nutrients are assimilated by wetland vegetation during the growing season, but neither tissue production nor microbial metabolic processes appeared to play a significant role in the observed patterns of surface-water chemical input-to-output relations on a seasonal basis. Presumably, internal cycling of nutrients sequestered in the sediments and detritus, combined with a summer increase in microbially mediated chemical transformations, obscured the effects of vegetative assimilation during the summer on surface-water chemical loads. Additionally, the natural confinement of most flows within the banks of Irondequoit Creek, which resulted in passage of stormwater through the wetland with little dispersion or detention in the cattail and backwater areas, diminished the capability of the wetland to improve water quality. Additional factors that probably affected the chemical-removal efficiency of the wetland included chemical inflow loading rates, storage and release mechanisms of the sediments (sedimentation, adsorption, filtration, precipitaton, dissolution, and resuspension), and accretion and burial of organic matter. Measurements of chlorophyll_ a concentrations, and calculations of potential phosphorus concentrations, since the 1970’s indicate an improvement in the trophic state of Irondequoit Bay. Estimated average annual loads (1990-96) of selected constituents entering Irondequoit Bay indicate that, since 1980, the loads of all major forms of nitrogen have decreased, chloride loads have increased, and sulfate loads have changed little. Inputs of total phosphorus and suspended solids to the wetland have increased since 1980, possibly as a result of increased erosion by stormflows from an increasingly developed watershed. The wetland decreases the loads of these constituents, but the trends of these loads entering Irondequoit Bay cannot be reliably defined because the removal efficiencies during the two earlier study periods (1980–81 and 1984–88) are known.

Water-Resources Investigations Report↗

USGS2010

Archean through Mesoproterozoic metallogenesis and tectonics of northeast Asia, Chapter 4 in Metallogenesis and tectonics of northeast Asia

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that have been led by the U.S. Geological Survey (USGS). These studies have produced two broad types of publications (1) a series of regional geologic, mineral-deposit, and metallogenic-belt maps, with companion descriptions of the region, and (2) a suite of metallogenic and tectonic analyses of the same region. The study area consists of eastern Russia (most of eastern Siberia and the Russian Far East), Mongolia, northern China, South Korea, Japan, and adjacent offshore areas. The major cooperative agencies are the Russian Academy of Sciences; the Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation; the Mongolian Academy of Sciences; the Mongolian University of Science and Technology; the Mongolian National University; Jilin University, Changchun, People?s Republic of China, the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; the University of Texas, Arlington, and the U.S. Geological Survey (USGS). This study builds on and extends the data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Survey of Canada. The major products of this project were summarized by Naumova and others (2006) and are described in appendix A.

Professional Paper↗

USGS2012

Groundwater quality in the Owens Valley, California

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Owens Valley are completed to depths between 210 and 480 feet (64 to 146 meters), consist of solid casing from the land surface to a depth of 50 to 80 feet (15 to 24 meters), and are screened or perforated below the solid casing.

California↗

USGS2013

Technical evaluation of a total maximum daily load model for Upper Klamath and Agency Lakes, Oregon

We reviewed a mass balance model developed in 2001 that guided establishment of the phosphorus total maximum daily load (TMDL) for Upper Klamath and Agency Lakes, Oregon. The purpose of the review was to evaluate the strengths and weaknesses of the model and to determine whether improvements could be made using information derived from studies since the model was first developed. The new data have contributed to the understanding of processes in the lakes, particularly internal loading of phosphorus from sediment, and include measurements of diffusive fluxes of phosphorus from the bottom sediments, groundwater advection, desorption from iron oxides at high pH in a laboratory setting, and estimates of fluxes of phosphorus bound to iron and aluminum oxides. None of these processes in isolation, however, is large enough to account for the episodically high values of whole-lake internal loading calculated from a mass balance, which can range from 10 to 20 milligrams per square meter per day for short periods. The possible role of benthic invertebrates in lake sediments in the internal loading of phosphorus in the lake has become apparent since the development of the TMDL model. Benthic invertebrates can increase diffusive fluxes several-fold through bioturbation and biodiffusion, and, if the invertebrates are bottom feeders, they can recycle phosphorus to the water column through metabolic excretion. These organisms have high densities (1,822–62,178 individuals per square meter) in Upper Klamath Lake. Conversion of the mean density of tubificid worms (Oligochaeta) and chironomid midges (Diptera), two of the dominant taxa, to an areal flux rate based on laboratory measurements of metabolic excretion of two abundant species suggested that excretion by benthic invertebrates is at least as important as any of the other identified processes for internal loading to the water column. Data from sediment cores collected around Upper Klamath Lake since the development of the TMDL model also contributed to this review. Cores were sequentially extracted to determine the distribution of phosphorus associated with several matrices in the sediment (freely exchangeable, metal-oxides, acid-soluble minerals, and residual). The concentrations of phosphorus in these fractions varied around the lake in patterns that reflect transport processes in the lake and the ultimate deposition of organic and inorganic forms of phosphorus from the water column. Both organic and inorganic phosphorus had higher concentrations in the northern part of the lake, in and just west of Goose Bay. At the time that these cores were collected, prior to restoration of the Williamson River Delta, this area was close to the shoreline of the lake and east of the Williamson River mouth. This contrasts with erosional inputs, which, in addition to being high to the east of the pre-restoration Williamson River mouth, were higher in the middle of the lake than at the northern end. Organic forms of phosphorus had particularly high concentrations in the northern bays. When these cores were used to calculate a new estimate of the whole-lake-averaged concentration of total phosphorus in the top 10 centimeters of the lake sediments, the estimate was about one-third of the best estimate available when the TMDL model was developed.

Oregon↗

USGS1997

The origin and distribution of HAPs elements in relation to maceral composition of the A1 lignite bed (Paleocene, Calvert Bluff Formation, Wilcox Group), Calvert mine area, east-central Texas

The origin and distribution of twelve potentially Hazardous Air Pollutants (HAPs; As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) identified in the 1990 Clean Air Act Amendments were examined in relation to the maceral composition of the A1 bed (Paleocene, Calvert Bluff Formation, Wilcox Group) of the Calvert mine in east-central Texas. The 3.2 m-thick A1 bed was divided into nine incremental channel samples (7 lignite samples and 2 shaley coal samples) on the basis of megascopic characteristics. Results indicate that As, Cd, Cr, Ni, Pb, Sb, and U are strongly correlated with ash yield and are enriched in the shaley coal samples. We infer that these elements are associated with inorganic constituents in the coal bed and may be derived from a penecontemporaneous stream channel located several kilometers southeast of the mining block. Of the HAPs elements studied, Mn and Hg are the most poorly correlated to ash yield. We infer an organic association for Mn; Hg may be associated with pyrite. The rest of the trace elements (Be, Co, and Se) are weakly correlated with ash yield. Further analytical work is necessary to determine the mode of occurrence for these elements. Overall, concentrations of the HAPs elements are generally similar to or less than those reported in previous studies of lignites of the Wilcox Group, east-central region, Texas. Petrographic analysis indicates the following ranges in composition for the seven lignite samples: liptinites (5–8%), huminites (88–95%), and inertinites (trace amounts to 7%). Samples from the middle portion of the A1 bed contain abundant crypto-eugelinite compared to the rest of the samples; this relationship suggests that the degradation of plant material was an important process during the development of the peat mire. With the exception of Hg and Mn, relatively low levels of the HAPs elements studied are found in the samples containing abundant crypto-eugelinite. We infer that the peat-forming environment for this portion of the coal bed was very wet with minimal detrital input. Relatively high concentrations of crypto-humotelinite were found in samples from the top and base of the coal bed. The presence of abundant crypto-humotefinite in this part of the coal bed suggests the accumulation of wood-rich peat under conditions conducive to a high degree of tissue preservation in the peat mire. Although several of the trace elements (Be, Co, Ni, and Sb) exhibit enrichment in these samples, they are not necessarily chemically associated with humotelinite. We infer that these elements, with the exception of Be, are possibly associated with deposition of the roof and floor rock of the coal bed; however, further analytical work would be necessary to confirm this hypothesis. Beryllium may have an organic origin.

International Journal of Coal Geology↗

USGS2011

Analysis of dispersion and attenuation of surface waves in poroelastic media in the exploration-seismic frequency band

We analyse dispersion and attenuation of surface waves at free surfaces of possible vacuum/poroelastic media: permeable-‘open pore’, impermeable-‘closed pore’ and partially permeable boundaries, which have not been previously reported in detail by researchers, under different surface-permeable, viscous-damping, elastic and fluid-flowing conditions. Our discussion is focused on their characteristics in the exploration-seismic frequency band (a few through 200 Hz) for near-surface applications. We find two surface-wave modes exist, R 1 waves for all conditions, and R 2 waves for closed-pore and partially permeable conditions. For R 1 waves, velocities disperse most under partially permeable conditions and least under the open-pore condition. High-coupling damping coefficients move the main dispersion frequency range to high frequencies. There is an f 1 frequency dependence as a constant- Q model for attenuation at high frequencies. R 1 waves for the open pore are most sensitive to elastic modulus variation, but least sensitive to tortuosities variation. R 1 waves for partially permeable surface radiate as non-physical waves (Im( k ) < 0) at low frequencies. For R 2 waves, velocities are slightly lower than the bulk slow P 2 waves. At low frequencies, both velocity and attenuation are diffusive of f 1/2 frequency dependence, as P 2 waves. It is found that for partially permeable surfaces, the attenuation displays - f 1 frequency dependence as frequency increasing. High surface permeability, low-coupling damping coefficients, low Poisson′s ratios, and low tortuosities increase the slope of the - f 1 dependence. When the attenuation coefficients reach 0, R 2 waves for partially permeable surface begin to radiate as non-physical waves.

Geophysical Journal International↗