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At least 379 records · Page 21Linked to original sources
USGS2013

Construction of a 3-arcsecond digital elevation model for the Gulf of Maine

A system-wide description of the seafloor topography is a basic requirement for most coastal oceanographic studies. The necessary detail of the topography obviously varies with application, but for many uses, a nominal resolution of roughly 100 m is sufficient. Creating a digital bathymetric grid with this level of resolution can be a complex procedure due to a multiplicity of data sources, data coverages, datums and interpolation procedures. This report documents the procedures used to construct a 3-arcsecond (approximately 90-meter grid cell size) digital elevation model for the Gulf of Maine (71°30' to 63° W, 39°30' to 46° N). We obtained elevation and bathymetric data from a variety of American and Canadian sources, converted all data to the North American Datum of 1983 for horizontal coordinates and the North American Vertical Datum of 1988 for vertical coordinates, used a combination of automatic and manual techniques for quality control, and interpolated gaps using a surface-fitting routine.

Maine↗
USGS1949

Interpreting ground conditions from geologic maps

Intelligent planning for heavy construction, water supply, or other land utilization requires advance knowledge of ground conditions in the area. It is essential to know: the topography, that is, the configuration of the land surface; the geology and soils, that is, the deposits that compose the land and its weathered surface; and the hydrology, that is, the occurrence of water whether under or on the ground. These elements usually are considered in planning land developments that involve much investment; detailed surveys generally are made of the topography, geology, soils, and hydrology at the site selected for development. Such detailed surveys are essential, but equally essential and often overlooked is the need for general surveys prior to site selection. Only if the general surveys have been made is it possible to know that a particular site is most suitable for the purpose and that no situations in the tributary areas that might affect the project have been overlooked. Moreover, the general regional relations must be known in order to properly interpret the geology, soils, and hydrology at a particular locality. In brief, both the general and the specific are needed in order to avoid costly mistakes either during or after development. The accompanying maps illustrate how a general geologic map can be used for interpreting grc .d conditions during a planning stage prior to site selection. The topographic and geologic maps, which provide the basic data, have been simplified from some existing ones. The interpretive sheets are intended to provide some examples of the kinds of information that trained persons can read from such basic maps.

Circular↗
USGS1974

Hydrologic Unit Map -- 1974, Minnesota

This map and accompanying table show Hydrologic Units that are basically hydrographic in nature. The Cataloging Units shown will supplant the Cataloging Units previously used by the U.S. Geological Survey in its Catalog of Information on Water Data (1966-72).

Minnesota↗
USGS1983

Selected data for low-temperature (less than 90 degrees C) geothermal systems in the United States; reference data for U.S. Geological Survey Circular 892

Supporting data are presented for the 1982 low-temperature geothermal resource assessment of the United States. Data are presented for 2072 geothermal sites which are representative of 1168 low-temperature geothermal systems identified in 26 States. The low-temperature geothermal systems consist of 978 isolated hydrothermal-convection systems, 148 delineated-area hydrothermal-convection systems, and 42 delineated-area conduction-dominated systems. The basic data and estimates of reservoir conditions are presented for each geothermal system, and energy estimates are given for the accessible resource base, resource, and beneficial heat for each isolated system.

Open-File Report↗
USGS1972

Factors contributing to unusually low runoff during the period 1962-68 in the Concho River Basin, Texas

To determine the reasons for the unusually low runoff in the Concho River basin during the period 1962-68, the physical developments and climatic changes in the basin were identified and related to changes in the regimen of streamflow. Land use, brush infestation, and land-treatment practices have not caused significant changes in the rainfall-runoff relationship. The use of surface water for irrigation has increased very little during the past 70 years, and although the use of ground water for irrigation has greatly increased in the past 25 years, springflow has not been significantly diminished. The base flow of the streams is materially reduced by surface-water irrigation diversions. Diversions for municipal and industrial use have increased rapidly, but these diversions affect only the streamflow downstream from San Angelo. Statistical analyses showed the annual rainfall to be highly variable, with little serial correlation. Records of rainfall during the period 1943-68 are significantly different in character from previous long-term records. The frequency of monthly rainfall equal to or greater than 2.0 inches during the period 1943-68, and especially during the period 1962-68, was significantly less than the long-term averages. Analyses of annual runoff data, adjusted for depletions, show large variations in annual runoff. Coefficients of variation ranged from 0.8 to 1.4, and first-order serial correlations ranged from 0.01 to 0.28. The estimated recurrence interval of the 1962-68 drought is about 200 years. The analyses of rainfall-intensity and runoff data indicate that the basic cause for the relatively low runoff during the period 1962-68 was the lack of high-intensity, long-duration storms rather than any physical changes or agricultural practices in the watershed

Texas↗
USGS2013

Final report and archive of the swath bathymetry and ancillary data collected in the Puerto Rico Trench region in 2002 and 2003

In 2002 and 2003, the U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), conducted three exploration cruises that mapped for the first time the morphology of the entire tectonic plate boundary stretching from the Dominican Republic in the west to the Lesser Antilles in the east, a distance of approximately 700 kilometers (430 miles). Observations from these three exploration cruises, coupled with computer modeling and published Global Positioning System (GPS) results and earthquake focal mechanisms, have provided new information that is changing the evaluation of the seismic and tsunami hazard from this plate boundary. The observations collected during these cruises also contributed to the basic understanding of the mechanisms that govern plate tectonics, in this case, the creation of the island of Puerto Rico and the deep trench north of it. Results of the sea floor mapping have been an important component of the study of tsunami and earthquake hazards to the northeastern Caribbean and the U.S. Atlantic coast off the United States.

Puerto Rico↗
USGS2017

A field study of selected U.S. Geological Survey analytical methods for measuring pesticides in filtered stream water, June - September 2012

U.S. Geological Survey monitoring programs extensively used two analytical methods, gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry, to measure pesticides in filtered water samples during 1992–2012. In October 2012, the monitoring programs began using direct aqueous-injection liquid chromatography tandem mass spectrometry as a new analytical method for pesticides. The change in analytical methods, however, has the potential to inadvertently introduce bias in analysis of datasets that span the change. A field study was designed to document performance of the new method in a variety of stream-water matrices and to quantify any potential changes in measurement bias or variability that could be attributed to changes in analytical methods. The goals of the field study were to (1) summarize performance (bias and variability of pesticide recovery) of the new method in a variety of stream-water matrices; (2) compare performance of the new method in laboratory blank water (laboratory reagent spikes) to that in a variety of stream-water matrices; (3) compare performance (analytical recovery) of the new method to that of the old methods in a variety of stream-water matrices; (4) compare pesticide detections and concentrations measured by the new method to those of the old methods in a variety of stream-water matrices; (5) compare contamination measured by field blank water samples in old and new methods; (6) summarize the variability of pesticide detections and concentrations measured by the new method in field duplicate water samples; and (7) identify matrix characteristics of environmental water samples that adversely influence the performance of the new method. Stream-water samples and a variety of field quality-control samples were collected at 48 sites in the U.S. Geological Survey monitoring networks during June–September 2012. Stream sites were located across the United States and included sites in agricultural and urban land-use settings, as well as sites on major rivers. The results of the field study identified several challenges for the analysis and interpretation of data analyzed by both old and new methods, particularly when data span the change in methods and are combined for analysis of temporal trends in water quality. The main challenges identified are large (greater than 30 percent), statistically significant differences in analytical recovery, detection capability, and (or) measured concentrations for selected pesticides. These challenges are documented and discussed, but specific guidance or statistical methods to resolve these differences in methods are beyond the scope of the report. The results of the field study indicate that the implications of the change in analytical methods must be assessed individually for each pesticide and method. Understanding the possible causes of the systematic differences in concentrations between methods that remain after recovery adjustment might be necessary to determine how to account for the differences in data analysis. Because recoveries for each method are independently determined from separate reference standards and spiking solutions, the differences might be due to an error in one of the reference standards or solutions or some other basic aspect of standard procedure in the analytical process. Further investigation of the possible causes is needed, which will lead to specific decisions on how to compensate for these differences in concentrations in data analysis. In the event that further investigations do not provide insight into the causes of systematic differences in concentrations between methods, the authors recommend continuing to collect and analyze paired environmental water samples by both old and new methods. This effort should be targeted to seasons, sites, and expected concentrations to supplement those concentrations already assessed and to compare the ongoing analytical recovery of old and new methods to those observed in the summer and fall of 2012.

Scientific Investigations Report↗
USGS2016

Response of periphyton fatty acid composition to supplemental flows in the upper Esopus Creek, Catskill Mountains, New York

Fatty acid analysis of periphyton is an emerging tool for assessing the condition of a stream ecosystem on the basis of its water quality. The study presented in this report was designed to test the hypothesis that periphyton communities have a fatty acid profile that can detect excessive turbidity and suspended sediment. The fatty acid composition of periphyton was assessed during two seasons upstream and downstream from an underground aqueduct that provides supplemental flows, which are a potential source of turbidity and suspended sediment on the upper Esopus Creek, New York. These data were compared with measurements of periphyton standing crop, diatom community structure and integrity, and basic water-quality parameters. Periphyton standing crop and diatom community integrity indicated little evidence of impairment from the supplemental flows. The relative abundances of two physiologically important fatty acids, γ-linolenic acid (18:3ω6) and eicosapentaenoic acid (20:5ω3), were significantly lower downstream from the supplemental flows and multivariate analyses of fatty acid profiles identified significant differences between sites upstream and downstream from the supplemental flows. Individual fatty acids and summary metrics, however, were not significantly correlated with turbidity or suspended sediment. Together, these results indicate that the supplemental flows may cause some measurable effects but they do not constitute a major disturbance to the periphyton community on the upper Esopus Creek. Fatty acid analysis may have potential as a tool for monitoring changes in periphyton nutritional composition that may reflect water quality and ecosystem health but needs to be further evaluated around a more definitive source of water-quality impairment.

New York↗
USGS1962

Current studies of the hydrology of prairie potholes

The prairie potholes in the North-Central States and in Canada are of glacial origin. Because many of them contain ponds or marshes, they are important in the production of livestock and waterfowl. The objective of the present investigation is to determine the amount of water that accumulates in and is used in the potholes in their natural environment. Two study areas were selected in North Dakota, and construction of gaging facilities was completed in 1960. Each study area contains four potholes. Three of the potholes for each area contain dense growths of aquatic vegetation, and one is clear of aquatic vegetation. The instruments to provide the basic data for computing water losses include: water-stage recorder, water-temperature recorder, rain gage, anemometer, and hygrothermograph. Observations will also be made of ground-water levels, rate of growth and type of vegetation, and quality of water.

Circular↗
USGS2012

Core Science Systems—Mission overview

The Core Science Systems Mission Area delivers nationally focused Earth systems and information science that provides fundamental research and data that underpins all Mission Areas of the USGS, the USGS Science Strategy, and Presidential, Secretarial, and societal priorities. — Kevin T. Gallagher, Associate Director, Core Science Systems The U.S. Geological Survey (USGS) Core Science Systems (CSS) Mission Area spans the Earth's "Critical Zone" (National Research Council, 2001). The Critical Zone is the near-surface interface that extends from the tops of the trees down to the base of the deepest groundwater. CSS provides a foundation for all USGS Mission Areas, as well as for the mission of the Department of the Interior (DOI), in the following ways: Conducts basic and applied science research and development Fosters broad understanding and application of analyses and information Provides a framework for data and information sharing Creates new geospatially enabled data and information Provides technical expertise in standards and methods Builds and facilitates partnerships and innovation

Fact Sheet↗
USGS1975

Land subsidence and tectonism, Raft River Valley, Idaho

A comparison of 1974 leveling data with elevations established 40 years earlier reveals two types of vertical ground movement which have occurred in Raft River Valley, Idaho: (1) regional differential movement of about 0.22 ft (6.4 cm), apparently due to tectonism, and (2) extensive land subsidence of as much as 2.61 ft (0.80 m) caused by withdrawal of ground water. Data are too sparse to calculate the magnitude or areal extent of subsidence; however, tentative lines of equal subsidence suggest that the area affected by subsidence probably exceeds 100 mi 2 (260 km 2 ). In order to estimate historic subsidence or subsidence potential in Raft River Valley serious consideration should be given to a field program of basic-data collection. Leveling along a few carefully selected lines of existing control and the installation and operation of extensometer water-level recorders in areas of continuing water-level decline would provide useful data for evaluating past and estimating future subsidence.

Idaho↗
USGS2013

Description of input and examples for PHREEQC version 3: A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations

PHREEQC version 3 is a computer program written in the C and C++ programming languages that is designed to perform a wide variety of aqueous geochemical calculations. PHREEQC implements several types of aqueous models: two ion-association aqueous models (the Lawrence Livermore National Laboratory model and WATEQ4F), a Pitzer specific-ion-interaction aqueous model, and the SIT (Specific ion Interaction Theory) aqueous model. Using any of these aqueous models, PHREEQC has capabilities for (1) speciation and saturation-index calculations; (2) batch-reaction and one-dimensional (1D) transport calculations with reversible and irreversible reactions, which include aqueous, mineral, gas, solid-solution, surface-complexation, and ion-exchange equilibria, and specified mole transfers of reactants, kinetically controlled reactions, mixing of solutions, and pressure and temperature changes; and (3) inverse modeling, which finds sets of mineral and gas mole transfers that account for differences in composition between waters within specified compositional uncertainty limits. Many new modeling features were added to PHREEQC version 3 relative to version 2. The Pitzer aqueous model ( pitzer.dat database, with keyword PITZER ) can be used for high-salinity waters that are beyond the range of application for the Debye-Hückel theory. The Peng-Robinson equation of state has been implemented for calculating the solubility of gases at high pressure. Specific volumes of aqueous species are calculated as a function of the dielectric properties of water and the ionic strength of the solution, which allows calculation of pressure effects on chemical reactions and the density of a solution. The specific conductance and the density of a solution are calculated and printed in the output file. In addition to Runge-Kutta integration, a stiff ordinary differential equation solver (CVODE) has been included for kinetic calculations with multiple rates that occur at widely different time scales. Surface complexation can be calculated with the CD-MUSIC (Charge Distribution MUltiSIte Complexation) triple-layer model in addition to the diffuse-layer model. The composition of the electrical double layer of a surface can be estimated by using the Donnan approach, which is more robust and faster than the alternative Borkovec-Westall integration. Multicomponent diffusion, diffusion in the electrostatic double layer on a surface, and transport of colloids with simultaneous surface complexation have been added to the transport module. A series of keyword data blocks has been added for isotope calculations— ISOTOPES, CALCULATE_VALUES, ISOTOPE_ALPHAS, ISOTOPE_RATIOS, and NAMED_EXPRESSIONS . Solution isotopic data can be input in conventional units (for example, permil, percent modern carbon, or tritium units) and the numbers are converted to moles of isotope by PHREEQC. The isotopes are treated as individual components (they must be defined as individual master species) so that each isotope has its own set of aqueous species, gases, and solids. The isotope-related keywords allow calculating equilibrium fractionation of isotopes among the species and phases of a system. The calculated isotopic compositions are printed in easily readable conventional units. New keywords and options facilitate the setup of input files and the interpretation of the results. Keyword data blocks can be copied (keyword COPY ) and deleted (keyword DELETE ). Keyword data items can be altered by using the keyword data blocks with the _MODIFY extension and a simulation can be run with all reactants of a given index number (keyword RUN_CELLS ). The definition of the complete chemical state of all reactants of PHREEQC can be saved in a file in a raw data format ( DUMP and _RAW keywords). The file can be read as part of another input file with the INCLUDE$ keyword. These keywords facilitate the use of IPhreeqc, which is a module implementing all PHREEQC version 3 capabilities; the module is designed to be used in other programs that need to implement geochemical calculations; for example, transport codes. Charting capabilities have been added to some versions of PHREEQC. Charting capabilities have been added to Windows distributions of PHREEQC version 3. (Charting on Linux requires installation of Wine.) The keyword data block USER_GRAPH allows selection of data for plotting and manipulation of chart appearance. Almost any results from geochemical simulations (for example, concentrations, activities, or saturation indices) can be retrieved by using Basic language functions and specified as data for plotting in USER_GRAPH . Results of transport simulations can be plotted against distance or time. Data can be added to a chart from tab-separated-values files. All input for PHREEQC version 3 is defined in keyword data blocks, each of which may have a series of identifiers for specific types of data. This report provides a complete description of each keyword data block and its associated identifiers. Input files for 22 examples that demonstrate most of the capabilities of PHREEQC version 3 are described and the results of the example simulations are presented and discussed.

Techniques and Methods↗
USGS1979

Evaluation of the geologic and hydrologic factors related to the waste-storage potential of Mesozoic aquifers in the southern part of the Atlantic Coastal Plain, South Carolina and Georgia

The report describes the subsurface distribution of rocks of Cretaceous to Late Jurassic( ) age in the Atlantic Coastal Plain , South Carolina, and Georgia, and examines their potential for deep-well waste storage into th part of the regional sediment mass which lies below the deepest zones containing usable ground waters. For the study, usable ground water is considered to be that which contains less than 10,000 mg/L dissolved solids. Using a group of geohydrologic parameters derived from or combining 21 categories of basic data, established from study and interpretation of well cuttings and geophysical logs, a series of 32 regional maps and 8 stratigraphic cross sections was constructed. For each of the eight geologic units delineated in the subsurface, the maps illustrate the distribution of waste-storage potential in terms of areal extent, depth below land surface, sand-shale geometry, and the approximate sodium chloride concentration of a unit 's nonusable ground water. In areas where the geologic units contain nonusable ground water, the depth below land surface and the thickness of potential waste-storage reservoir and reservoir-seal combinations are variable. The range in variability appears to be broad enough to meet the need for a wide choice among the geologic requirements that would normally be considered in selecting specific waste-storage sites for detailed examination. (Woodard-USGS)

Georgia, South Carolina↗
USGS2010

Volcano-Monitoring Instrumentation in the United States, 2008

The United States is one of the most volcanically active countries in the world. According to the global volcanism database of the Smithsonian Institution, the United States (including its Commonwealth of the Northern Mariana Islands) is home to about 170 volcanoes that are in an eruptive phase, have erupted in historical time, or have not erupted recently but are young enough (eruptions within the past 10,000 years) to be capable of reawakening. From 1980 through 2008, 30 of these volcanoes erupted, several repeatedly. Volcano monitoring in the United States is carried out by the U.S. Geological Survey (USGS) Volcano Hazards Program, which operates a system of five volcano observatories-Alaska Volcano Observatory (AVO), Cascades Volcano Observatory (CVO), Hawaiian Volcano Observatory (HVO), Long Valley Observatory (LVO), and Yellowstone Volcano Observatory (YVO). The observatories issue public alerts about conditions and hazards at U.S. volcanoes in support of the USGS mandate under P.L. 93-288 (Stafford Act) to provide timely warnings of potential volcanic disasters to the affected populace and civil authorities. To make efficient use of the Nation's scientific resources, the volcano observatories operate in partnership with universities and other governmental agencies through various formal agreements. The Consortium of U.S. Volcano Observatories (CUSVO) was established in 2001 to promote scientific cooperation among the Federal, academic, and State agencies involved in observatory operations. Other groups also contribute to volcano monitoring by sponsoring long-term installation of geophysical instruments at some volcanoes for specific research projects. This report describes a database of information about permanently installed ground-based instruments used by the U.S. volcano observatories to monitor volcanic activity (unrest and eruptions). The purposes of this Volcano-Monitoring Instrumentation Database (VMID) are to (1) document the Nation's existing, ground-based, volcano-monitoring capabilities, (2) answer queries within a geospatial framework about the nature of the instrumentation, and (3) provide a benchmark for planning future monitoring improvements. The VMID is not an archive of the data collected by monitoring instruments, nor is it intended to keep track of whether a station is temporarily unavailable due to telemetry or equipment problems. Instead, it is a compilation of basic information about each instrument such as location, type, and sponsoring agency. Typically, instruments installed expressly for volcano monitoring are emplaced within about 20 kilometers (km) of a volcanic center; however, some more distant instruments (as far away as 100 km) can be used under certain circumstances and therefore are included in the database. Not included is information about satellite-based and airborne sensors and temporarily deployed instrument arrays, which also are used for volcano monitoring but do not lend themselves to inclusion in a geospatially organized compilation of sensor networks. This Open-File Report is provided in two parts: (1) an Excel spreadsheet (http://pubs.usgs.gov/of/2009/1165/) containing the version of the Volcano-Monitoring Instrumentation Database current through 31 December 2008 and (2) this text (in Adobe PDF format), which serves as metadata for the VMID. The disclaimer for the VMID is in appendix 1 of the text. Updated versions of the VMID will be posted on the Web sites of the Consortium of U.S. Volcano Observatories (http://www.cusvo.org/) and the USGS Volcano Hazards Program http://volcanoes.usgs.gov/activity/data/index.php.

Alaska, Arizona, California, Colorado, Hawaii, New↗
USGS2009

User Manual for the Data-Series Interface of the Gr Application Software

This manual describes the data-series interface for the Gr Application software. Basic tasks such as plotting, editing, manipulating, and printing data series are presented. The properties of the various types of data objects and graphical objects used within the application, and the relationships between them also are presented. Descriptions of compatible data-series file formats are provided.

Open-File Report↗
USGS1987

Review of the Water Resources Information System of Argentina

A representative of the U.S. Geological Survey traveled to Buenos Aires, Argentina, in November 1986, to discuss water information systems and data bank implementation in the Argentine Government Center for Water Resources Information. Software has been written by Center personnel for a minicomputer to be used to manage inventory (index) data and water quality data. Additional hardware and software have been ordered to upgrade the existing computer. Four microcomputers, statistical and data base management software, and network hardware and software for linking the computers have also been ordered. The Center plans to develop a nationwide distributed data base for Argentina that will include the major regional offices as nodes. Needs for continued development of the water resources information system for Argentina were reviewed. Identified needs include: (1) conducting a requirements analysis to define the content of the data base and insure that all user requirements are met, (2) preparing a plan for the development, implementation, and operation of the data base, and (3) developing a conceptual design to inform all development personnel and users of the basic functionality planned for the system. A quality assurance and configuration management program to provide oversight to the development process was also discussed. (USGS)

Open-File Report↗
USGS2008

Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption

The rapid onset of energetic seismicity on September 23, 2004, at Mount St. Helens caused seismologists at the Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques that summarized and displayed seismic parameters for use by scientists and the general public. Such techniques included webicorders (Web-based helicorder-like displays), graphs showing RSAM (real-time seismic amplitude measurements), RMS (root-mean-square) plots, spectrograms, location maps, automated seismic-event detectors, focal mechanism solutions, automated approximations of earthquake magnitudes, RSAM-based alarms, and time-depth plots for seismic events. Many of these visual-information products were made available publicly as Web pages generated and updated routinely. The graphs and maps included short written text that explained the concepts behind them, which increased their value to the nonseismologic community that was tracking the eruption. Laypeople could read online summaries of the scientific interpretations and, if they chose, review some of the basic data, thereby providing a better understanding of the data used by scientists to make interpretations about ongoing eruptive activity, as well as a better understanding of how scientists worked to monitor the volcano.

Washington↗
USGS2012

Nearshore morphology, benthic structure, hydrodynamics, and coastal groundwater discharge near Kahekili Beach Park, Maui, Hawaii

This report presents a brief summary of recent fieldwork conducted off Kahekili Beach Park, Maui, Hawaii, the site of the newly established U.S. Coral Reef Task Force priority study area at Kaanapali and the Hawaii Department of Land and Natural Resources, Division of Aquatic Resources, Kahekili Herbivore Fisheries Management Area (HFMA). The goals of this fieldwork are to provide new baseline information to help guide future studies and to provide first insights into rates and drivers of coastal groundwater discharge and associated constituent loadings into the priority study area's coastal waters. This study presents the first swath acoustic mapping information, in situ oceanographic instrument measurements, and coastal groundwater discharge estimates at this site based on the submarine groundwater discharge tracer radon-222 ( 222 Rn). Coastal groundwater discharge rates ranged from about 22 to 50 centimeters per day, depending on proximity of the sampling mooring to the primary discharge vent. The water chemistry of the discharging groundwater was at times dramatically different than ambient seawater. For example, at the primary vent site at Kahekili, the concentrations of total dissolved nitrogen (TDN), dissolved silicate (DSi), and total dissolved phosphorus (TDP) in the discharging groundwater were 43.75 micromolar (μM), 583.49 μM, and 12.04 μM, respectively. These data extend our basic understanding of the morphology, benthic structure, and oceanographic setting of this vent site and provide a first estimate of the magnitude and physical forcings of submarine groundwater discharge and associated trace metals and nutrient loads here.

Hawai'i↗