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USGS2017

Geochemistry of mercury and other constituents in subsurface sediment—Analyses from 2011 and 2012 coring campaigns, Cache Creek Settling Basin, Yolo County, California

Cache Creek Settling Basin was constructed in 1937 to trap sediment from Cache Creek before delivery to the Yolo Bypass, a flood conveyance for the Sacramento River system that is tributary to the Sacramento–San Joaquin Delta. Sediment management options being considered by stakeholders in the Cache Creek Settling Basin include sediment excavation; however, that could expose sediments containing elevated mercury concentrations from historical mercury mining in the watershed. In cooperation with the California Department of Water Resources, the U.S. Geological Survey undertook sediment coring campaigns in 2011–12 (1) to describe lateral and vertical distributions of mercury concentrations in deposits of sediment in the Cache Creek Settling Basin and (2) to improve constraint of estimates of the rate of sediment deposition in the basin. Sediment cores were collected in the Cache Creek Settling Basin, Yolo County, California, during October 2011 at 10 locations and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Unsplit cores were logged for two geophysical parameters (gamma bulk density and magnetic susceptibility); then, selected cores were split lengthwise. One half of each core was then photographed and archived, and the other half was subsampled. Initial subsamples from the cores (20-centimeter composite samples from five predetermined depths in each profile) were analyzed for total mercury, methylmercury, total reduced sulfur, iron speciation, organic content (as the percentage of weight loss on ignition), and grain-size distribution. Detailed follow-up subsampling (3-centimeter intervals) was done at six locations along an east-west transect in the southern part of the Cache Creek Settling Basin and at one location in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This report documents site characteristics; field and laboratory methods; and results of the analyses of each core section and subsample of these sediment cores, including associated quality-assurance and quality-control data.

California↗

USGS2011

Documentation for a web site to serve ULF-EM (Ultra-Low Frequency Electromagnetic) data to the public

The Stanford Ultra-Low Frequency Electromagnetic (ULF-EM) Monitoring Project is recording naturally varying electromagnetic signals adjacent to active earthquake faults, in an attempt to establish whether there is any variation in these signals associated with earthquakes. Our project is collaborative between Stanford University, the U.S. Geological Survey (USGS), and UC Berkeley. Lead scientists are Simon Klemperer (Stanford University), Jonathan Glen (USGS) and Darcy Karakelian McPhee (USGS). Our initial sites are in the San Francisco Bay Area, monitoring different strands of the San Andreas fault system, at Stanford University's Jasper Ridge Biological Preserve (JRSC), Marin Headlands of the Golden Gate National Recreation Area (MHDL), and the UC Berkeley's Russell Reservation Field Station adjacent to Briones Regional Park (BRIB). In addition, we maintain in conjunction with the Berkeley Seismological Laboratory (BSL) two remote reference stations at the Bear Valley Ranch in Parkfield, Calif., (PKD) and the San Andreas Geophysical Observatory at Hollister, Calif., (SAO). Metadata about our site can be found at http://ulfem-data.stanford.edu/info.html. Site descriptions can be found at the BSL at http://seismo.berkeley.edu/, and seismic data can be obtained from the Northern California Earthquake Data Center at http://www.ncedc.org/. The site http://ulfem-data.stanford.edu/ allows access to data from the Stanford-USGS sites JRSC, MHDL and BRIB, as well as UC Berkeley sites PKD and SAO.

Open-File Report↗

USGS2012

Precision of geodolite surveys: A reply to Jackson and Cheng

Jackson and Cheng have suggested that the changes in areal dilatation measured in Geodolite surveys by the U.S. Geological Survey may be simply an artifact of the measuring system. Although systematic error could conceivably account for the observed excursions in dilatation, we maintain that the specific criticisms by Jackson and Cheng are incorrect: the excursions in dilatation cannot be attributed to the offset correction nor to proportional error associated with temperature. The absence of both errors is demonstrated by using data that are particularly sensitive to the two effects.

Journal of Geophysical Research B: Solid Earth↗

USGS2014

Appendix B—investigations of underground‐water problems in California, New Mexico, and Oregon

Investigations by the California Department of Public Works, Division of Water Resources (based on written communication from Harold Conkling, Deputy State Engineer)—the Division of Water Resources, California Department of Public Works, has in the past year conducted investigations of ground‐water problems in the great central valley of the State (California Trough); in the Salinas and Santa Clara Valleys of the central part of the State; also in the South Coastal Basin and in Ventura County, in southern California. In these investigations the Bureau of Agricultural Engineering of the United States Department of Agriculture, the Geological Survey of the United States Department of the Interior, and many local agencies have cooperated. In large part, the activities of the past year are continuations of investigations summarized in an earlier statement (A. M. Piper, Investigations of underground‐water problems in Arizona, California, New Mexico, and Oregon, National Research Council, Trans. Amer. Geophys. Union, 13th annual meeting, 308–309, 1932). Progress in 1932–35 is summarized in the following paragraphs.

California, New Mexico, Oregon↗

USGS2002

Geologic, hydrologic, and water-quality data from multiple-well monitoring sites in the Central and West Coast basins, Los Angeles County, California, 1995-2000

In 1995, the U.S. Geological Survey (USGS), in cooperation with the Water Replenishment District of Southern California (WRDSC) , began a study to examine ground-water resources in the Central and West Coast Basins in Los Angeles County, California. The study characterizes the geohydrology and geochemistry of the regional ground-water flow system and provides extensive data for evaluating ground-water management issues. This report is a compilation of geologic, hydrologic, and water-quality data collected from 24 recently constructed multiple-well monitoring sites for the period 1995–2000. Descriptions of the collected drill cuttings were compiled into lithologic logs, which are summarized along with geophysical logs—including gamma-ray, spontaneous potential, resistivity, electromagnetic induction, and temperature tool logs—for each monitoring site. At selected sites, cores were analyzed for magnetic orientation, physical and thermal properties, and mineralogy. Field and laboratory estimates of hydraulic conductivity are presented for most multiple-well monitoring sites. Periodic water-level measurements are also reported. Water-quality information for major ions, nutrients, trace elements, deuterium and oxygen-18, and tritium is presented for the multiple-well monitoring locations, and for selected existing production and observation wells. In addition, boron-11, carbon-13, carbon-14, sulfur-34, and strontium-87/86 data are presented for selected wells.

Open-File Report↗

USGS2019

Drilling, construction, water chemistry, water levels, and regional potentiometric surface of the upper carbonate-rock aquifer in Clark County, Nevada, 2009–2015

The U.S. Geological Survey (USGS) and the Bureau of Land Management (BLM) initiated a cooperative study through the Southern Nevada Public Land Management Act (Bureau of Land Management, 1998) to install six wells in the carbonate-rock and basin-fill aquifers of Clark County, Nevada, in areas of sparse groundwater data. This map uses water levels from these new wells, water levels from existing wells, and altitudes of spring discharge points to update a regional potentiometric map of the carbonate-rock aquifer and provide evidence to interpret the direction of regional groundwater flow. This potentiometric surface map is accompanied by drilling and borehole geophysical logs, well construction information, lithology, water chemistry, and water levels from the newly drilled wells.

Scientific Investigations Map↗

USGS2011

Geology, Hydrology, and Water Quality of the Little Blackwater River Watershed, Dorchester County, Maryland, 2006-09

The Little Blackwater River watershed is a low-lying tidal watershed in Dorchester County, Maryland. The potential exists for increased residential development in a mostly agricultural watershed that drains into the Blackwater National Wildlife Refuge. Groundwater and surface-water levels were collected along with water-quality samples to document hydrologic and geochemical conditions within the watershed prior to potential land-use changes. Lithologic logs were collected in the Little Blackwater River watershed and interpreted with existing geophysical logs to conceptualize the shallow groundwater-flow system. A shallow water table exists in much of the watershed as shown by sediment cores and surface geophysical surveys. Water-table wells have seasonal variations of 6 feet, with the lowest water levels occurring in September and October. Seasonally low water-table levels are lower than the stage of the Little Blackwater River, creating the potential for surface-water infiltration into the water table. Two stream gages, each equipped with stage, velocity, specific conductance, and temperature sensors, were installed at the approximate mid-point of the watershed and near the mouth of the Little Blackwater River. The gages recorded data continuously and also were equipped with telemetry. Discharge calculated at the mouth of the Little Blackwater River showed a seasonal pattern, with net positive discharge in the winter and spring months and net negative discharge (flow into the watershed from Blackwater National Wildlife Refuge and Fishing Bay) in the summer and fall months. Continuous water-quality records showed an increase in specific conductance during the summer and fall months. Discrete water-quality samples were collected during 2007--08 from 13 of 15 monitoring wells and during 2006--09 from 9 surface-water sites to characterize pre-development conditions and the seasonal variability of inorganic constituents and nutrients. The highest mean values of nitrogen are found in the deep groundwater system, with relatively low values in the water table. Surface-water-quality samples in the lower half of the basin show a significant increase in inorganic seawater constituents, especially in summer, corresponding with net negative discharge from the Little Blackwater River. Samples also were collected from nine wells and four surface-water sites for pesticides in June 2008. The herbicides atrazine, metolachlor, and simazine, and the insecticide fipronil were detected at each of the four surface-water sites, with concentrations less than 2 micrograms per liter. Concentrations of pesticides found in groundwater were typically one to two orders of magnitude lower than pesticide concentrations found in surface water of the Little Blackwater River. Seasonal hydraulic-gradient reversals between the shallow groundwater system and the Little Blackwater River, coincident with the inflow of brackish water from Fishing Bay and Blackwater National Wildlife Refuge, indicate a potential for saltwater intrusion into the water table. The likelihood of saltwater intrusion into the water table is further supported by high chloride concentrations observed in water-table wells near the Little Blackwater River.

Scientific Investigations Report↗

USGS2014

Diabase dikes of the Franklin Furnace, New Jersey, quadrangle

Two of the numerous small dikes mapped on the areal geology sheet of the Franklin Furnace Folio (U.S. Geological Survey 161) as “Mostly basic, including nepheline tinguaite, leucite tinguaite, and camptonite” of post‐Ordovician age, have been found to be quite distinct from these alkalic rocks, and the two dikes in question are indistinguishable from the Triassic diabase found elsewhere in New Jersey and adjoining States. The association of diabase with highly alkalic rocks has been observed and commented on by numerous writers. There is evidence pointing to the post‐Triassic age of the Beemerville alkaline rocks, and a possible correlation with a volcanic ash of Cretaceous age found by Stephenson and Carter at Haddonfield, New Jersey, near Camden, in 1936. ©1938. American Geophysical Union. All Rights Reserved.

New Jersey↗

USGS2011

Online interactive U.S. Reservoir Sedimentation Survey Database

In April 2009, the U.S. Geological Survey and the Natural Resources Conservation Service (prior to 1994, the Soil Conservation Service) created the Reservoir Sedimentation Survey Database (RESSED) and Web site, the most comprehensive compilation of data from reservoir bathymetric and dry basin surveys in the United States. RESSED data can be useful for a number of purposes, including calculating changes in reservoir storage characteristics, quantifying rates of sediment delivery to reservoirs, and estimating erosion rates in a reservoir's watershed.

Eos, Transactions, American Geophysical Union↗

USGS1989

Non-energy resources, Connecticut and Rhode Island coastal waters

Cores collected from Long Island Sound, Connecticut, were used to establish control on the geologic framework of the area. Lithologic and stratigraphic analyses verified the presence of the following units: (1) Cretaceous coastal plain, (2) Pleistocene glacial till, (3) late Pleistocene glacial lake, (4) late Pleistocene glacial outwash, and (5) Holocene fluvial, estuarine and marine deposits. Cores collected in Block Island Sound, Rhode Island, were obtained from inferred, relict shoreline features and were analyzed for heavy mineral content. Concentrations ranged from 0.3 to 3.4%; no significant downcore changes were found. The results indicated that surficial sediments in areas of high-velocity tidal flow yield greater amounts of heavy minerals than do inferred placer deposits. During the second phase of the program of study, Connecticut and Rhode Island pooled resources to develop a study plan for the comprehensive quantification of all non-energy resources in the adjacent waters of the states. A literature and data survey was conducted to assess the occurrence, extent, and accessibility of these resources. Sand and gravel and heavy minerals were found in concentrations offering potential for resource exploitation. Constraints on exploitation include (1) water depth restrictions for the protection of shellfish beds and public beaches, (2) fishing activities, (3) military, commercial, and fishing vessel traffic, (4) seafloor cable routes and (5) dump sites. Deposits composed of Pleistocene glacial sediments and/or Holocene marine sediments in regions of little or no user conflict were identified as sites potentially suitable for resource exploitation. The study plan stated additional data needs (geophysical profiling and vibracore sampling) at these sites. Subsequent to these recommendations, high-resolution seismic profiles and sidescan sonographs were obtained from these sites. Seismic stratigraphic analyses confirm the presence of extensive deposits of potential economic value.

Marine Geology↗

USGS2007

Magnetic character of a large continental transform: an aeromagnetic survey of the Dead Sea Fault

New high-resolution airborne magnetic (HRAM) data along a 120-km-long section of the Dead Sea Transform in southern Jordan and Israel shed light on the shallow structure of the fault zone and on the kinematics of the plate boundary. Despite infrequent seismic activity and only intermittent surface exposure, the fault is delineated clearly on a map of the first vertical derivative of the magnetic intensity, indicating that the source of the magnetic anomaly is shallow. The fault is manifested by a 10–20 nT negative anomaly in areas where the fault cuts through magnetic basement and by a <5 nT positive anomaly in other areas. Modeling suggests that the shallow fault is several hundred meters wide, in agreement with other geophysical and geological observations. A magnetic expression is observed only along the active trace of the fault and may reflect alteration of magnetic minerals due to fault zone processes or groundwater flow. The general lack of surface expression of the fault may reflect the absence of surface rupture during earthquakes. The magnetic data also indicate that unlike the San Andreas Fault, the location of this part of the plate boundary was stable throughout its history. Magnetic anomalies also support a total left-lateral offset of 105–110 km along the plate boundary, as suggested by others. Finally, despite previous suggestions of transtensional motion along the Dead Sea Transform, we did not identify any igneous intrusions related to the activity of this fault segment.

Dead Sea Fault↗

USGS2023

Shallow fault slip of the 2020 M5.1 Sparta, North Carolina, earthquake

The 2020 M 5.1 Sparta, North Carolina, earthquake is the largest in the eastern United States since the 2011 M 5.8 Mineral, Virginia, earthquake and produced a ∼2.5‐km‐long surface rupture, unusual for an event of this magnitude. A geological field study conducted soon after the event indicates oblique slip along a east‐southeast‐trending fault with a consistently observed thrust component. My analysis of regional seismic waveforms, Interferometric Synthetic Aperture Radar, and Global Positioning System survey data yields a compact shallow rupture extending from Earth’s surface down‐dip to the southwest over a ∼3 km fault length. The inferred kinematic rupture is primarily toward the up‐dip and eastward along‐strike directions and has predominantly thrust motion in the west, transitioning to roughly equal thrust and left‐lateral strike‐slip motion in the east. No normal faulting component, as proposed in an earlier geophysical study, is necessary to explain the data. The prevalence of only dip‐slip motions observed at Earth’s surface may demand slip partitioning between dip slip and lateral motions at depth.

North Carolina, Virginia, West Virginia↗

USGS2015

Aquifer geometry, lithology, and water levels in the Anza–Terwilliger area—2013, Riverside and San Diego Counties, California

The population of the Anza–Terwilliger area relies solely on groundwater pumped from the alluvial deposits and surrounding bedrock formations for water supply. The size, characteristics, and current conditions of the aquifer system in the Anza–Terwilliger area are poorly understood, however. In response to these concerns, the U.S. Geological Survey, in cooperation with the High Country Conservancy and Rancho California Water District, undertook a study to (1) improve mapping of groundwater basin geometry and lithology and (2) to resume groundwater-level monitoring last done during 2004–07 in the Anza–Terwilliger area. Inversion of gravity data, including new data collected for this study, was done to estimate the thickness of the alluvial deposits that form the Cahuilla and Terwilliger groundwater basins and to understand the geometry of the underlying basement complex. After processing of the gravity data, the thickness of the alluvial aquifer materials was modeled by using all available lithology, density, and geophysical data. The thickest alluvial deposits (greater than 500 feet) are in the northern part of the study area along the south side of the San Jacinto fault zone, in the southern part of the Cahuilla groundwater basin, and in the western part of the Terwilliger groundwater basin. Through most of the area of alluvial materials, the thickness of the alluvium estimated from gravity data is less than 400 feet. Analysis of more than 900 drillers’ logs indicated that in areas having relatively thick alluvium, particularly along the San Jacinto fault zone and in the Terwilliger Valley, the alluvium is predominantly composed of sands and gravels. Fine-textured sediments appeared to be discontinuous rather than forming laterally extensive, low-permeability layers. More than 500 drillers’ logs indicated only bedrock is present, indicating that the fractured bedrock is an important source of groundwater, primarily for domestic use, in the study area. The depths of the holes drilled into the bedrock indicated that fractures potentially supplying water to wells persist in the upper few hundred feet and that the permeable zone of the fractured bedrock extends to depths greater than weathered zones in the upper part of the basement complex. Water-level data were collected from 59 wells during fall 2013. These data indicated that hydraulic head did not vary substantially with well depth and that the measured water levels in bedrock and alluvium were similar. Large offsets in groundwater altitude across the San Jacinto fault zone indicated that the fault zone is a barrier to groundwater flow in the northeastern part of the Anza Valley. On the basis of data from 33 wells, water levels mostly declined between the fall of 2006 and the fall of 2013; the median decline was 5.1 feet during this period, for a median rate of decline of about 0.7 feet/year. Based on data from 40 wells, water-level changes between fall 2004 and fall 2013 were variable in magnitude and trend, but had a median decline of 2.4 feet and a median rate of decline of about 0.3 feet/ year. These differences in apparent rates of groundwater-level change highlight the value of ongoing water-level measurements to distinguish decadal, or longer term, trends in groundwater storage often associated with climatic variability and trends. Fifty-four long-term hydrographs indicated the sensitivity of groundwater levels to climatic conditions; they also showed a general decline in water levels across the study area since 1986 and, in some cases, dating back to the 1950s.

California↗

USGS1977

Hydrologic characteristics of the Madison Limestone, the Minnelusa Formation, and equivalent rocks as determined by well-logging formation evaluation, Wyoming, Montana, South Dakota, and North Dakota

Geophysical logs from wells distributed throughout the Powder River Basin were digitized, processed, and interpreted to get a regional understanding of the lithologic and ground-water characteristics of aquifers in the Madison Limestone and Minnelusa Formation. The percentage of sand, porosity, and apparent ground-water resistivity of the Minnelusa closely follow structural trends in the basin. Values increase from the structural axis of the basin toward the flanks. Close correlations between the water resistivities in the Madison and the Minnelusa indicate possible hydrologic connection between the two units. The low primary porosity from geophysical logs in the Madison indicates that secondary porosity is necessary to develop water supplies of economic importance from the Madison. Because of increased porosity and better water quality, the flanks of the basin appear to be the most favorable places for water production from either the Madison or the Minnelusa.

Wyoming, Montana, South Dakota, North Dakota↗

USGS2011

Studying geodesy and earthquake hazard in and around the New Madrid Seismic Zone

Workshop on New Madrid Geodesy and the Challenges of Understanding Intraplate Earthquakes; Norwood, Massachusetts, 4 March 2011 Twenty-six researchers gathered for a workshop sponsored by the U.S. Geological Survey (USGS) and FM Global to discuss geodesy in and around the New Madrid seismic zone (NMSZ) and its relation to earthquake hazards. The group addressed the challenge of reconciling current geodetic measurements, which show low present-day surface strain rates, with paleoseismic evidence of recent, relatively frequent, major earthquakes in the region. The workshop presentations and conclusions will be available in a forthcoming USGS open-file report (http://pubs.usgs.gov).

Eos, Transactions, American Geophysical Union↗

USGS2011

Seismograms offer insight into Oklahoma City bombing

The terrorist bombing of the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995, generated seismic waves that were recorded on two permanent seismographs about 7 and 26 km away from the bombing. The seismogram recorded at 26 km shows two low-frequency wave trains, discrete sets of oscillatory signals, that begin about 10 s apart. Public release of this record prompted speculation that each wave train was caused by a different energy source. On May 23, 1995, the U.S. Geological Survey monitored the demolition of the bomb-ravaged Federal Building with portable seismographs (Figure 1). Two wave trains were picked up again. The recordings indicate that the wave trains during both the bombing and demolition represent seismic waves traveling at different velocities. We conclude that the two wave trains recorded during the bombing are consistent with a single impulsive energy source.

Oklahoma↗

USGS2011

The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to and participated in HVO’s mission during this past century. First and foremost, we owe a debt of gratitude to the late Thomas A. Jaggar, Jr., the geologist whose vision and efforts led to the founding of HVO. We also acknowledge the pioneering contributions of the late Frank A. Perret, who began the continuous monitoring of Kīlauea in 1911, setting the stage for Jaggar, who took over the work in 1912. Initial support for HVO was provided by the Massachusetts Institute of Technology (MIT) and the Carnegie Geophysical Laboratory, which financed the initial cache of volcano monitoring instruments and Perret’s work in 1911. The Hawaiian Volcano Research Association, a group of Honolulu businessmen organized by Lorrin A. Thurston, also provided essential funding for HVO’s daily operations starting in mid-1912 and continuing for several decades. Since HVO’s beginning, the University of Hawaiʻi (UH), called the College of Hawaii until 1920, has been an advocate of HVO’s scientific studies. We have benefited from collaborations with UH scientists at both the Hilo and Mänoa campuses and look forward to future cooperative efforts to better understand how Hawaiian volcanoes work. The U.S. Geological Survey (USGS) has operated HVO continuously since 1947. Before then, HVO was under the administration of various Federal agencies—the U.S. Weather Bureau, at the time part of the Department of Agriculture, from 1919 to 1924; the USGS, which first managed HVO from 1924 to 1935; and the National Park Service from 1935 to 1947. For 76 of its first 100 years, HVO has been part of the USGS, the Nation’s premier Earth science agency. It currently operates under the direction of the USGS Volcano Science Center, which now supports five volcano observatories covering six U.S. areas—Hawaiʻi (HVO), Alaska and the Northern Mariana Islands (Alaska Volcano Observatory), Washington and Oregon (Cascades Volcano Observatory), California (California Volcano Observatory), and the Yellowstone region (Yellowstone Volcano Observatory). Although the National Park Service (NPS) managed HVO for only 12 years, HVO has enjoyed a close working relationship with Hawaiʻi Volcanoes National Park (named Hawaii National Park until 1961) since the park’s founding in 1916. Today, as in past years, the USGS and NPS work together to ensure the safety and education of park visitors. We are grateful to all park employees, particularly Superintendent Cindy Orlando and Chief Ranger Talmadge Magno and their predecessors, for their continuing support of HVO’s mission. HVO also works closely with the Hawaiʻi County Civil Defense. During volcanic and earthquake crises, we have appreciated the support of civil defense staff, especially that of Harry Kim and Quince Mento, who administered the agency during highly stressful episodes of Kīlauea's ongoing eruption. Our work in remote areas on Hawaiʻi’s active volcanoes is possible only with the able assistance of Hawaiʻi County and private pilots who have safely flown HVO staff to eruption sites through the decades. A special mahalo goes to David Okita, who has been HVO’s principal helicopter pilot for more than two decades. Many commercial and Civil Air Patrol pilots have also assisted HVO by reporting their observations during various eruptive events. Hawaiʻi’s news media—print, television, radio, and online sources—do an excellent job of distributing volcano and earthquake information to the public. Their assistance is invaluable to HVO, especially during times of crisis. HVO’s efforts to provide timely and accurate scientific information about Hawaiian volcanoes and earthquakes succeed only because of you, our receptive and keenly aware public. By following the activity of Hawaiʻi’s active volcanoes through our daily eruption updates posted on the HVO website, viewing HVO webcam images, reading our weekly “Volcano Watch” articles, and attending our public lectures, you help us to ensure that you can live safely with Hawaiʻi’s dynamic volcanoes. To everyone who has shared in HVO’s reaching this milestone—100 years of continuous volcano monitoring—we extend our deepest gratitude. Mahalo nui loa!

Hawai'i↗

USGS2007

Integrated geoscience studies in the Greater Yellowstone Area - Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

Yellowstone National Park, rimmed by a crescent of older mountainous terrain, has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of volcanism, tectonism, and later glaciation. Its spectacular hydrothermal systems cap this landscape. From 1997 through 2003, the United States Geological Survey Mineral Resources Program conducted a multidisciplinary project of Yellowstone National Park entitled Integrated Geoscience Studies of the Greater Yellowstone Area, building on a 130-year foundation of extensive field studies (including the Hayden survey of 1871, the Hague surveys of the 1880s through 1896, the studies of Iddings, Allen, and Day during the 1920s, and NASA-supported studies starting in the 1970s—now summarized in USGS Professional Paper 729 A through G) in this geologically dynamic terrain. The project applied a broad range of scientific disciplines and state-of-the-art technologies targeted to improve stewardship of the unique natural resources of Yellowstone and enable the National Park Service to effectively manage resources, protect park visitors from geologic hazards, and better educate the public on geologic processes and resources. This project combined a variety of data sets in characterizing the surficial and subsurface chemistry, mineralogy, geology, geophysics, and hydrothermal systems in various parts of the park. The sixteen chapters presented herein in USGS Professional Paper 1717, Integrated Geoscience Studies in the Greater Yellowstone Area—Volcanic, Tectonic, and Hydrothermal Processes in the Yellowstone Geoecosystem , can be divided into four major topical areas: (1) geologic studies, (2) Yellowstone Lake studies, (3) geochemical studies, and (4) geophysical studies. The geologic studies include a paper by Ken Pierce and others on the influence of the Yellowstone hotspot on landscape formation, the ecological effects of the hotspot, and the human experience and human geography of the greater Yellowstone ecosystem as influenced by the Yellowstone hotspot. Another paper by Paul Carrara describes the recent movement of a large landslide block dated by tree-ring analyses in the Tower Falls area. The section under Yellowstone Lake studies begins with a classic paper by J. David Love and others on ancestral Lake Yellowstone. Other papers in this section include results and interpretation of the high-resolution bathymetric, seismic reflection, and submersible studies by Lisa Morgan and others. Ken Pierce and others describe results from their studies of shorelines along Yellowstone Lake and their interpretation of inflation-deflation cycles, tilting, and faulting in the Yellowstone caldera. The influence of sublacustrine hydrothermal vent fluids on the geochemistry of Yellowstone Lake is described by Laurie Balistrieri and others. In Pat Shanks and others’ chapter, hydrothermal reactions, stable-isotope systematics, sinter deposition, and spire formation are related to the geochemistry of sublacustrine hydrothermal deposits in Yellowstone Lake. The geochemical studies section considers park-wide geochemical systems in Yellowstone National Park. In Bob Rye and Alfred Truesdell’s paper, the question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park is discussed. Irving Friedman and Dan Norton report on the chloride flux emissions from Yellowstone in their paper questioning whether Yellowstone is losing its steam. Wildlife issues as addressed by examining trace-element and stable-isotope geochemistry are discussed in a chapter by Maurice Chaffee and others. In another chapter by Chaffee and others, natural and anthropogenic anomalies and their potential impact on the environment using geochemistry is reported. Pam Gemery-Hill and others present geochemical data for selected rivers, lake waters, hydrothermal vents, and subaerial geysers for the time interval of 1996–2004. The life cycle of gold deposits near the northeast corner of the park is discussed by Brad Van Gosen. Under the geophysical studies segment, Ray Kokaly and others use AVIRIS (Airborne Visible and Infrared Spectroscopy) data to map vegetation cover and microbial communities in Yellowstone National Park. Eric Livo and others report their results using AVIRIS data on hydrothermally altered rock and hot-spring deposits. In his final paper following a half century of scientific research, Irving Friedman presents data on monitoring changes in geothermal activity at Norris Geyser Basin using satellite telemetry. These papers summarize a near-decade-long effort by the USGS from the late 1990s to mid-2000s. In 2001, the USGS in cooperation with the National Park Service (Yellowstone National Park) and the University of Utah established the Yellowstone Volcano Observatory, the 5th volcano observatory in the United States.

Professional Paper↗