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

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At least 1,081 records · Page 60Linked to original sources
USGS2017

A new high-precision borehole-temperature logging system used at GISP2, Greenland, and Taylor Dome, Antarctica

We describe a high-precision (0.1–1.0 mK) borehole-temperature (BT) logging system developed at the United States Geological Survey (USGS) for use in remote polar regions. We discuss calibration, operational and data-processing procedures, and present an analysis of the measurement errors. The system is modular to facilitate calibration procedures and field repairs. By interchanging logging cables and temperature sensors, measurements can be made in either shallow air-filled boreholes or liquid-filled holes up to 7 km deep. Data can be acquired in either incremental or continuous-logging modes. The precision of data collected by the new logging system is high enough to detect and quantify various thermal effects at the milli-Kelvin level. To illustrate this capability, we present sample data from the 3 km deep borehole at GISP2, Greenland, and from a 130 m deep air-filled hole at Taylor Dome, Antarctica. The precision of the processed GISP2 continuous temperature logs is 0.25–0.34 mK, while the accuracy is estimated to be 4.5 mK. The effects of fluid convection and the dissipation of the thermal disturbance caused by drilling the borehole are clearly visible in the data. The precision of the incremental Taylor Dome measurements varies from 0.11 to 0.32 mK. depending on the wind strength during the experiments. With this precision, we found that temperature fluctuations and multi-hour trends in the BT measurements correlate well with atmospheric-pressure changes.

Journal of Glaciology↗
USGS2019

A bibliometric profile of the Remote Sensing Open Access Journal published by MDPI between 2009 and 2018

Remote Sensing Open Access Journal (RS OAJ) is an international leading journal in the field of remote sensing science and technology. It was first published in the year 2009 and is currently celebrating tenth year of publications. In this research, a bibliometric analysis of RS OAJ was conducted based on 5588 articles published during the 10-year (2009–2018) time-period. The bibliometric analysis includes a comprehensive set of indicators such as dynamics and trends of publications, journal impact factor, total cites, eigenfactor score, normalized eigenfactor, CiteScore, h-index, h-classic publications, most productive countries (or territories) and institutions, co-authorship collaboration about countries (territories), research themes, citation impact of co-occurrences keywords, intellectual structure, and knowledge commutation. We found that publications of RS OAJ presented an exponential growth in the past ten years. From 2010 to 2017 (for which complete years data were available), the h-index of RS OAJ is 67. From 2009–2018, RS OAJ includes publications from 129 countries (or territories) and 3826 institutions. The leading nations contributing articles, based on 2009–2018 data, and listed based on ranking were: China, United States, Germany, Italy, France, Spain, Canada, England, Australia, Netherlands, Japan, Switzerland and Austria. The leading institutions, also for the same period and listed based on ranking were: Chinese Academy of Sciences, Wuhan University, University of Chinese Academy of Sciences, Beijing Normal University, The university of Maryland, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, China University of Geosciences, United States Geological Survey, German Aerospace Centre, University of Twente, and California Institute of Technology. For the year 2017, RS OAJ had an impressive journal impact factor of 3.4060, a CiteScore of 4.03, eigenfactor score of 0.0342, and normalized eigenfactor score of 3.99. In addition, based on 2009–2018, data co-word analysis determined that “remote sensing”, “MODIS”, “Landsat”, “LiDAR” and “NDVI” are the high-frequency of author keywords co-occurrence in RS OAJ. The main themes of RS OAJ are multi-spectral and hyperspectral remote sensing, LiDAR scanning and forestry remote sensing monitoring, MODIS and LAI data applications, Remote sensing applications and Synthetic Aperture Radar (SAR). Through author keywords citation impact analysis, we find the most influential keyword is Unmanned Aerial Vehicle (UAV), followed, forestry, Normalized Difference Vegetation Index (NDVI), terrestrial laser scanning, airborne laser scanning, forestry inventory, urban heat island, monitoring, agriculture, and laser scanning. By analyzing the intellectual structure of RS OAJ, we identify the main reference publications and find that the themes are about Random Forests, MODIS vegetation indices and image analysis, etc. RS OAJ ranks first in cited journals and third in citing, this indicates that RS OAJ has the internal knowledge flow. Our results will bring more benefits to scholars, researchers and graduate students, who hopes to get a quick overview of the RS OAJ. And this article will also be the starting point for communication between scholars and practitioners. Finally, this paper proposed a nuanced h-index (nh-index) to measure productivity and intellectual contribution of authors by considering h-index based on whether the one is first, second, third, or nth author. This nuanced approach to determining h-index of authors is powerful indicator of an academician’s productivity and intellectual contribution.

Remote Sensing↗
USGS2020

Evaluating elevation change thresholds between structure-from-motion DEMs derived from historical aerial photos and 3DEP LiDAR data

This study created digital terrain models (DTMs) from historical aerial images using Structure from Motion (SfM) for a variety of image dates, resolutions, and photo scales. Accuracy assessments were performed on the SfM DTMs, and they were compared to the United States Geological Survey’s three-dimensional digital elevation program (3DEP) light detection and ranging (LiDAR) DTMs to evaluate geomorphic change thresholds based on vertical accuracy assessments and elevation change methodologies. The results of this study document a relationship between historical aerial photo scales and predicted vertical accuracy of the resultant DTMs. The results may be used to assess geomorphic change thresholds over multi-decadal timescales depending on spatial scale, resolution, and accuracy requirements. This study shows that if elevation changes of approximately ±1 m are to be mapped, historical aerial photography collected at 1:20,000 scale or larger would be required for comparison to contemporary LiDAR derived DTMs.

Virginia↗
USGS2020

Harmonizing the Landsat ground reference with the Sentinel-2 Global Reference Image using space-based bundle adjustment

There is an ever-increasing need to use accurate and consistent geometric ground reference in the processing of remotely sensed data products as it reduces the burden on the end-users to account for the differences between the data products from different missions. In this regard, United States Geological Survey (USGS) initiated an effort to harmonize the Landsat ground reference with the Sentinel-2 Global Reference Image (GRI) to improve the co-registration between the data products of the two global medium-resolution missions. In this paper, we have discussed the process, results, and the improvements expected from this harmonization of two ground references using space-triangulation based bundle adjustment techniques. The ground coordinates of the Landsat reference library, consisting of 5 million Ground Control Points (GCPs) were adjusted in a series of four simultaneous bundle block adjustments using thousands of Landsat-8 (L8) scenes anchored with more than 300,000 control points extracted from the GRI dataset. The net adjustments to each of the four blocks, namely, Australia, Americas, Eurasia, and Islands, varied anywhere from 1 m to 13 m, depending on the accuracy of the GCPs in these blocks. The use of the GRI dataset in our bundle adjustment not only improved the absolute accuracy of the Landsat ground reference but will also improve the co-registration between Sentinel-2 and Landsat terrain corrected products, as the European Space Agency plans to process the Sentinel-2 products using the GRI dataset. Independent validation of the Landsat products processed using harmonized GCPs with the GRI dataset indicated a global mis-registration error of less than 8 m Circular Error Probable at 90 % (CE90), an improvement from 25 meters prior to harmonization. The improvements to the Landsat products using the harmonized GCPs will be available to the public as part of Landsat Collection-2 processing by the end of 2020.

MDPI Remote Sensing↗
USGS2025

Central Valley Hydrologic Model version 2 (CVHM2): Decision support tool for groundwater and land subsidence management

The San Joaquin Valley (SJV) of California is one of the world’s most productive agricultural regions. Reliance on groundwater has led to some of the greatest rates of human-induced land subsidence in the world in the 20th century, as well as more recently. The United States Geological Survey (USGS) has recently developed an integrated surface–subsurface hydrologic model, the Central Valley Hydrologic Model 2 (CVHM2), that represents the major components of the hydrologic system of California’s Central Valley. In this study, CVHM2 was applied as a decision support tool while simulating various management strategies to mitigate the land subsidence caused by the extraction of groundwater. CVHM2 was extended through to 2073 and applied to simulate management scenarios in terms of three primary drivers and their impact on subsidence along the Delta–Mendota Canal (DMC), a critical piece of infrastructure in the western SJV. The drivers considered were agricultural water demands, managed aquifer recharge (MAR), and changes in future climate. The results show that future subsidence is most sensitive to water demands, second most sensitive to future changes in climate, and relatively insensitive to MAR when it is applied as a surface application in the western SJV. However, we demonstrate via proof-of-concept scenarios that the MAR is capable of arresting subsidence when implemented via injection below the Corcoran Clay Member of the Tulare Formation instead of as a surface application. We also examine the uncertainty that is the result of climate variability and how to use the tool to identify the most appropriate strategies to constrain future subsidence to acceptable levels.

California↗
USGS2014

Application of hydrologic tools and monitoring to support managed aquifer recharge decision making in the Upper San Pedro River, Arizona, USA

The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr). Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.

Arizona↗
USGS2012

LIDAR & SASW technologies for geotechnical earthquake engineering

Geotechnical engineering methods are validated through comparison of field‐data of surface deformations and sub‐surface state properties. Recent advances in non‐invasive surface imaging and sub‐surface stiffness characterization allow us to rapidly and inexpensively map these spatial and physical properties in two and three dimensions. In this paper, we discuss new technologies used at the United States Geological Survey (USGS), ground‐based LIDAR (Light Detection And Ranging) used to create ultra high‐resolution three‐dimensional digital terrain models, and surface wave methods used to characterize soil stiffness properties. The power of LIDAR technology in earthquake engineering is its ability to rapidly capture the extremely high detail of failure morphologies, to view them in orientations not previously possible, and to permanently archive them for the engineering research community. The power of surface wave methods, like Spectral Analysis of Surface Waves (SASW), is their ability to non‐invasively and rapidly characterize the stiffness of the ground, to be relatively lightweight and efficient in deployment; and to accurately profile difficult materials such as gravely deposits and stiff soils where conventional methods are not practical. Three active‐source SASW systems used by the USGS are described here, a single‐source harmonic wave vibration system; a large parallel‐array harmonic wave source system; and a seafloor harmonic wave source system. LIDAR and SASW methods allow researchers to directly relate detailed surface damage with the shear wave velocity properties of the ground. LIDAR imagery and movies, and SASW datasets can be viewed at http://walrus.wr.usgs.gov/geotech.

Conference Paper↗
USGS2017

Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005–2015

Glacier mass balance measurements help to provide an understanding of the behavior of glaciers and their response to local and regional climate. In 2005 the United States Geological Survey established a surface mass balance monitoring program on Sperry Glacier, Montana, USA. This project is the first quantitative study of mass changes of a glacier in the US northern Rocky Mountains and continues to the present. The following paper describes the methods used during the first 11 years of measurements and reports the associated results. From 2005 to 2015, Sperry Glacier had a cumulative mean mass balance loss of 4.37 m w.e. (water equivalent). The mean winter, summer, and annual glacier-wide mass balances were 2.92, −3.41, and −0.40 m w.e. yr −1 respectively. We derive these cumulative and mean results from an expansive data set of snow depth, snow density, and ablation measurements taken at selected points on the glacier. These data allow for the determination of mass balance point values and a time series of seasonal and annual glacier-wide mass balances for all 11 measurement years. We also provide measurements of glacier extent and accumulation areas for select years. All data have been submitted to the World Glacier Monitoring Service and are available at doi:10.5904/wgms-fog-2016-08 . This foundational work provides valuable insight about Sperry Glacier and supplies additional data to the worldwide record of glaciers measured using the glaciological method. Future research will focus on the processes that control accumulation and ablation patterns across the glacier. Also we plan to examine the uncertainties related to our methods and eventually quantify a more robust estimate of error associated with our results.

Montana↗
USGS2020

A global shape model for Saturn's moon Enceladus from a dense photogrammetric control network

A planetary bodys global shape provides both insight into its geologic evolution, and a key element of any Planetary Spatial Data Infrastructure (PSDI). NASAs Cassini mission to Saturn acquired more than 600 moderate- to high-resolution images (< 500 m/pixel) of the small, geologically active moon Enceladus. The moons internal global ocean and intriguing geology mark it as a candidate for future exploration and motivates the development of a PSDI. Recently, Bland et al. (2018) provided two foundational elements of this PSDI: geodetic control and orthoimages. To provide the third foundational data set we generate a new shape model for Enceladus from Cassini images and a dense photogrammetric control network (nearly 1 million tie points) using the United States Geological Surveys Integrated Software for Imagers and Spectrometers (ISIS) and the Ames Stereo Pipeline (ASP). The new shape model is near-global in extent and gridded to 2.2 km/pixel, ~50 times better resolution than previous global models. Our calculated triaxial shape, rotation rate, and pole orientation for Enceladus is consistent with current IAU values to within the error; however, we determined a new prime meridian offset (Wo) of 7.063o. We calculate Enceladus long-wavelength topography by subtracting the best-fit triaxial ellipsoid from our shape model. The result is comparable to previous global models but can resolve topographic features as small as 5-7 km across in certain areas. To evaluate the spatially varying quality of the model we calculate the point density (variable from 5 to more than 50 per pixel), normalized median absolute deviation of the points within each pixel (typically less than 100 m), and the minimum expected vertical precision of each point (ranging from 2 km to 29 m).

Conference Paper↗
USGS2020

Detection and measurement of land subsidence and uplift using interferometric synthetic aperture radar, San Diego, California, USA, 2016–2018

Land subsidence associated with groundwater-level declines is stipulated as an “undesirable effect” in California’s Sustainable Groundwater Management Act (SGMA), and has been identified as a potential issue in San Diego, California, USA. The United States Geological Survey (USGS), the Sweetwater Authority, and the City of San Diego, undertook a cooperative study to better understand the hydromechanical response of the coastal aquifer system using Interferometric Synthetic Aperture Radar (InSAR) techniques. Three periods of interest were analyzed for this study that correspond to the periods before and after two substantial changes were made to the location and volume of pumpage: (1) April–August 2016 when groundwater levels and land surface elevation were relatively stable during normal pumping, (2) September 2016–May 2017 when groundwater levels recovered and the land surface uplifted during a period of substantially reduced pumping, (3) June 2017–October 2018 when groundwater levels declined and land subsidence occurred when pumpage resumed and expanded to new wells. Spatial and temporal characterization of the hydromechanical response to changes in pumpage is important for managing land subsidence. Further study using InSAR techniques, especially when combined with ground-based geodetic and monitoring-well networks, will provide water managers information to help effectively manage groundwater resources as stipulated in the SGMA.

California↗
USGS2019

Windows to the deep 2018: Exploration of the southeast US Continental margin

Windows to the Deep 2018: Exploration of the Southeast US Continental Margin was a 36-day expedition aboard NOAA Ship Okeanos Explorer to acquire data on priority exploration areas identified by the ocean management and scientific communities. This expedition involved high-resolution multibeam sonar mapping and ROV dives, ranging from 340 m to 3,400 m depth, across the southeast US continental margin. Operations primarily targeted areas with potential to host deep-sea coral and sponge communities, including mounds, ridges, and terraced features on the continental slope. Dive sites also included maritime heritage sites, a submarine landslide feature, and several submarine canyon slopes, some of which exhibited evidence of active cold seeps. High biological abundance was noted at six of 17 dive sites, three of which also had high biological diversity. Additionally, deep-sea corals or sponges were observed on every dive except one, which was dedicated to gas seep exploration.

Atlantic Ocean, Blake Plateau, Stetson Mesa↗
USGS2004

Peracute sodium toxicity in free-ranging black-bellied whistling duck ducklings

From 23 to 25 July 2002, 98–103 newly hatched black-bellied whistling ducks ( Dendrocygna autumnalis ) were observed alive at an inland saline lake (La Sal Vieja) in Willacy County, Texas (USA). Seventy-one (71%) died after showing signs indicative of sodium toxicity within 5 hr of entering the water; some died within minutes. Six carcasses were sent to the United States Geological Survey, National Wildlife Health Center (Madison, Wisconsin, USA) for analysis, and brain sodium levels of all ducklings were above 2,000 parts per million wet weight. More black-bellied whistling duck ducklings are likely to have been affected, but they were not observed after hatching.

Texas↗
USGS2008

Moist-soil seed abundance in managed wetlands in the Mississippi Alluvial Valley

Managed moist-soil units support early succession herbaceous vegetation that produces seeds, tubers, and other plant parts used by waterfowl in the Mississippi Alluvial Valley (MAV), USA. We conducted a stratified multi-stage sample survey on state and federal lands in the MAV of Arkansas, Louisiana, Mississippi, and Missouri during autumns 2002?2004 to generate a contemporary estimate of combined dry mass of seeds and tubers (herein seed abundance) in managed moist-soil units for use by the Lower Mississippi Valley Joint Venture (LMVJV) of the North American Waterfowl Management Plan. We also examined variation in mean seed abundance among moist-soil units in 2003 and 2004 in relation to management intensity (active or passive), soil pH and nutrient levels, proportional occurrence of plant life-forms (e.g., grass, flatsedge, and forb; vine; woody plants), and unit area. Estimates of mean seed abundance were similar in 2002 (X over bar = 537.1 kg/ha, SE = 100.1) and 2004 (X over bar = 555.2 kg/ha, SE = 105.2) but 35?40% less in 2003 (X over bar = 396.8 kg/ha, SE = 116.1). Averaged over years, seed abundance was 496.3 kg/ha (SE = 62.0; CV = 12.5%). Multiple regression analysis indicated seed abundance varied among moist-soil units inversely with proportional occurrence of woody vegetation and unit area and was greater in actively than passively managed units (R2adj = 0.37). Species of early succession grasses occurred more frequently in actively than passively managed units (P < 0.09), whereas mid- and late-succession plants occurred more often in passively managed units (P < 0.02). We recommend the LMVJV consider 556 kg/ha as a measure of seed abundance for use in estimating carrying capacity in managed moist-soil units on public lands in the MAV. We recommend active management of moist-soil units to achieve maximum potential seed production and further research to determine recovery rates of seeds of various sizes from core samples and the relationship between seed abundance and unit area.

Journal of Wildlife Management↗
USGS2003

Use of the Legal-Institutional Analysis Model to assess hydropower licensing negotiations

In the United States, the Federal Energy Regulatory Commission (FERC) is responsible for issuing or renewing licenses for hydropower projects owned and operated by power companies. During the licensing process, these companies are required to consult with agencies and other parties that are affected by project operating regimes. Typical participants include state and federal fish and wildlife agencies, environmental interest groups, and the FERC. One of the most difficult tasks facing participants is to reach agreement about what kinds of environmental conditions should be placed on license. Researchers at the United States Geological Survey developed a model to analyze the institutional context of natural resource disputes. The Legal-Institutional Analysis Model (LIAM) is a computerized model that allows an analyst to determine the likely behavior of each organization in a conflict. The model also analyzes the types and levels of negotiating power held by each organization. Researchers at the USGS have used the model in several cases involving hydropower license applications. To use the model, they facilitate workshops for stakeholder groups in order to develop a shared understanding of the likely obstacles and opportunities for successful resolution of the issues. This allows a systematic workshop analyses to develop strategies for successful negotiations, because they are able to better understand the negotiation problem and work more effectively with both their allies and their competitors.

Conference Paper↗
USGS1986

STRONG-MOTION INSTRUMENTATION OF STRUCTURES IN CHARLESTON, SOUTH CAROLINA AND ELSEWHERE.

Instrumentation of structures is part of earthquake hazard mitigation program of many institutions, including the United States Geological Survey (USGS). The USGS Strong-Motion Instrumentation of Structures Program is designed to complement other programs and to implement its own, within budget and other constraints. This paper reviews the overall national effort, cites examples of structures implemented and describes progress made to date. A recent example of instrumentation of an eight-story building in Charleston, South Carolina is documented.

Conference Paper↗
USGS1993

Operation of a real-time warning system for debris flows in the San Francisco bay area, California

The United States Geological Survey (USGS) and the National Weather Service (NWS) have developed an operational warning system for debris flows during severe rainstorms in the San Francisco Bay region. The NWS makes quantitative forecasts of precipitation from storm systems approaching the Bay area and coordinates a regional network of radio-telemetered rain gages. The USGS has formulated thresholds for the intensity and duration of rainfall required to initiate debris flows. The first successful public warnings were issued during a severe storm sequence in February 1986. Continued operation of the warning system since 1986 has provided valuable working experience in rainfall forecasting and monitoring, refined rainfall thresholds, and streamlined procedures for issuing public warnings. Advisory statements issued since 1986 are summarized.

Conference Paper↗
USGS1998

Using hydrogeology to site wetland compensation

The Illinois State Geological Survey has designed an initial site evaluation (ISE) procedure to rapidly separate candidate sites that have favorable hydrogeologic characteristics for wetland restoration or creation from sites where success is doubtful or difficult. ISE aims to focus compensation efforts on sites where former wetland hydrology can be restored or where the hydrogeology of wetlands in similar landscape positions can be reproduced.

Conference Paper↗