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At least 127 records · Page 7Linked to original sources
USGS1961

Time of travel of water in the Ohio River, Pittsburgh to Cincinnati

This report presents a procedure for estimating the time of travel of water in the Ohio River from Pittsburgh, Pa., to Cincinnati, Ohio, under various river stage conditions. This information is primarily for use by civil defense officials and by others concerned with problems involving travel time of river water. Tables and charts are presented to show, for a particular stage or discharge at Cincinnati, the average time it would take for water to travel through the entire reach from Pittsburgh, or through successive intermediate segments of the reach. For example, when the discharge at Cincinnati is 200,000 cfs, travel time from Pittsburgh to Cincinnati, a distance of 470 miles, averages about 7 days; and for discharges of more than 200,000 cfs, the travel time decreases very slowly with increasing discharge. When the discharge is 30,000 cfs, travel time is about 28 days; and for discharges of less than 30,000 cfs, the travel time increases very rapidly with decreasing discharge. Estimates of travel time at low discharge are subject to large errors. Statistical analysis of the possible variations of upstream discharge for a given discharge at Cincinnati indicates that the shortest probable travel time from Pittsburgh to Cincinnati ranges from 56 percent of that under average conditions when the discharge at Cincinnati is 15,000 cfs to 93 percent of that under average conditions when the discharge at Cincinnati is 894,000 cfs. A chart showing the time distribution of flow at Cincinnati is presented so that the probable travel time of Ohio River water can be determined for any time of the year. This chart provides information which, when applied to the time-of-travel chart, shows that the most probable travel time of water from Pittsburgh to Cincinnati ranges from 160 hours in February to 1,250 hours in September. Also presented is a flow-duration curve that can be used to predict future discharges and, subsequently, times of travel, for use in long-range planning. The procedure used to compute time of travel is described in sufficient detail to make it usable as a guide for similar studies of other rivers that have deans and pools in the reach being studied. The computations for the time-of-travel charts were made as follows: (a) by dividing the reach between Pittsburgh and Cincinnati into four subreaches with a full-range streamgaging station at or near the ends of each; (b) by computing for each subreach mean velocities corresponding to various discharges at Cincinnati, using data obtained from river survey maps and data available from gaging station operations; (c) by assuming that any mass of contaminated water would travel at a rate equal to that of the mean velocity of the river water.

Ohio River↗
USGS1990

Levels at streamflow gaging stations

This manual establishes the surveying procedures for (1) setting gages at a streamflow gaging station to datum and (2) checking the gages periodically for errors caused by vertical movement of the structures that support them. Surveying terms and concepts are explained, and procedures for testing, adjusting, and operating the instruments are described in detail. Notekeeping, adjusting level circuits, checking gages, summarizing results, locating the nearest National Geodetic Vertical Datum of 1929 bench mark, and relating the gage datum to the national datum are also described.

Techniques of Water-Resources Investigations↗
USGS2019

North American Bat Monitoring Program regional protocol for surveying with stationary deployments of echolocation recording devices: Narrative version 1.0, Pacific Northwestern US

The outbreak of white-nose syndrome (WNS) and the growing awareness of the risks to bats from wind power generating facilities have driven radical changes to North American bat conservation. Over the last decade, formerly common species such as the little brown myotis (Myotis lucifugus) and hoary bat (Lasiurus cinereus) have experienced unprecedented mortality rates and are now facing non-trivial extinction risk. In response to this change, federal land management agencies such as the US National Park Service, US Fish and Wildlife Service, US Forest Service, US Bureau of Land Management and state wildlife management agencies such as the Oregon Department of Fish and Wildlife and Idaho Fish and Game have invested in collaborative, interagency bat monitoring to close the gap in information about bat welfare and to inform bat conservation strategies. Bats are notoriously difficult to track and study and there remains a paucity of fundamental information about the seasonal patterns of bat activity and habitat use and population distributions and abundances. Moreover, because bats are so highly mobile and difficult to survey (e.g., nocturnal flight), this information needs to be contextualized at broad regional (e.g., 10,000 km2) and range-wide extents. Delimiting bat populations at local scales (e.g., 100 km2) is very difficult and it is not clear, for example, how a declining trend in local (e.g., a small park unit) patterns of bat activity or relative abundance should be interpreted without broader context. In recognition of these challenges, a plan for coordinated continental-scale monitoring of bats, the North American Bat Monitoring Program (NABat) was developed (Loeb et al. 2015). The centerpiece of the plan is the use of a spatially-balanced randomized master sample of grid-cell sample units from a grid-based sampling frame to provide the architecture for collaboration and the statistical foundation for making inferences about bat populations across broad regions and entire bat geographic ranges. The plan outlines general goals, survey design, and field methods for both summertime acoustic surveys of bats as well as winter and summer counts of bats in hibernacula and maternity colonies but it does not provide field-level protocol and standard operating procedures for consistent and efficient implementation. This regional protocol provides these details for one component of NABat, the deployment of stationary acoustic detectors to record bats during summer, as is called for by the NABat plan. This protocol was written specifically to provide guidance and consistency across the Pacific Northwestern US (N. California [California Department of Fish and Wildlife Northern Region], Idaho, Washington, and Oregon; US Fish and Wildlife Service Region 1 and portion of Region 8 [in Northern California and Klamath Basin]; US Forest Service Region 6 and portions of Regions 1 and 5 in Idaho; and the Upper Columbia Basin, North Coast Cascades, and Klamath Networks of the National Park Service). This region has internal cohesion, sharing a distinct bat faunal assemblage of 15 species (with several additional species occurring on the southern periphery of the region), and a long history of collaborative bat monitoring beginning with the interagency Bat Grid Program which operated from 2003-2010 across Oregon and Washington (US Forest Service Region 6). This protocol will be coordinated and implemented by the Northwestern Bat Hub, on behalf of the collective interagency partnership. The Northwestern Bat Hub is housed on the Oregon State University-Cascades campus and leverages pooled partner funds and resources to maintain a small staff that coordinates and conducts monitoring, provides training and oversight, ensures high-quality data quality and control, and analyzes data and reports on results.

California, Idaho, Oregon, Washington↗
USGS2003

Collecting, shipping, storing, and imaging snow crystals and ice grains with low-temperature scanning electron microscopy

Methods to collect, transport, and store samples of snow and ice have been developed that enable detailed observations of these samples with a technique known as low-temperature scanning electron microscopy (LTSEM). This technique increases the resolution and ease with which samples of snow and ice can be observed, studied, and photographed. Samples are easily collected in the field and have been shipped to the electron microscopy laboratory by common air carrier from distances as far as 5,000 miles. Delicate specimens of snow crystals and ice grains survive the shipment procedures and have been stored for as long as 3 years without undergoing any structural changes. The samples are not subjected to the melting or sublimation artifacts. LTSEM allows individual crystals to be observed for several hours with no detectable changes. Furthermore, the instrument permits recording of photographs containing the parallax information necessary for three-dimensional imaging of the true shapes of snowflakes, snow crystals, snow clusters, ice grains, and interspersed air spaces. This study presents detailed descriptions of the procedures that have been used successfully in the field and the laboratory to collect, ship, store, and image snow crystals and ice grains. Published 2003 Wiley-Liss, Inc.

Microscopy Research and Technique↗
USGS1995

Cerro Prieto geothermal field, Mexico; chemical analyses and other data for 58 samples collected in 1977-1979

This report releases the results of selected chemical analyses by the USGS of fluids collected from geothennal power production wells at the Cerro Prieto Geothennal Field, Mexico. Cerro Prieto, the world's largest producing hot-water geothennal field, is located 32 km southeast of Mexicali, Baja California. Comision Federal de Electricidad de Mexico (CFE) gave permission for, and assisted in, sample collection. Data collection and reported analyses was made by the U.S. Geological Survey. Data collected in 1977 and 1978 where published previously by Ball and Jenne (1983) which was about half the data given here. This report also includes samples collected in 1979 which were not previously released. These activities, including this data release, are supported by the U.S. Department of Energy. Analyses given in the following section were made by James W. Ball and E.A. Jenne. The data have been reviewed with the assistance of Cathy Janik, USGS, Menlo Park. Some, but not all, details from Ball and Jenne (1983) concerning collection, and preservation and analytical procedures are repeated here. Nehring and Trusdell (1977) also provide an outline of some of the issues involved in the difficult task of collecting samples from geothermal wells. The initial intent of the study was to provide basic data for use in determining how these fluids should be managed either in disposal or in reinjection. Some of the hot, corrosive brines were separated as two-phase (water and steam) samples under pressure using a coiled condenser tube submerged in an ice/water mixture (called "condensed" samples). It is not known if these were total flow samples. Other samples were collected from the brine sampling valve of the separators (called "flashed" samples). Analyses given in the following section area sorted by (1) well number, (2) date, and (3) sample type(s). Analysis was by a Spectraspan III d.c. argon plasma emission spectrometer with a Spectraject III torch (Ball and Jenne, 1983). Elements were determined in two groups using interchangeable cassettes. Group one included B, Mn, Cu, Zn, Si, Zr, Be, Mn, Sr, Ti, Ca, Fe, Ba, K, Na, Rb, and Al. Group two included As, Se, Bi, Zn, Cd, Sb, Cu, Ni, Hg, Mo, Co, Cr, Fe, V, Tl, Li, and Pb. Ball and Jenne (1983) noted that analysis of B, Ca, Mg, Ba, and Sr generally gave precise results. Movement of the plasma or grating was observed to affect sensitivity over short time periods even while the instrument was carefully standardized and optimized. Sensitivity was also a function of sample concentration. All samples at the time of analysis contained a white precipitate (perhaps colloidal silica) thus the reported concentrations may not accurately represent the concentrations present at the time of collection (Ball and Jenne, 1983). Additional details about specific elements are given in the section on "Evaluation of data" (Bliss, this volume) following the data table.

Open-File Report↗
USGS2015

U.S. Geological Survey Noble Gas Laboratory’s standard operating procedures for the measurement of dissolved gas in water samples

This report addresses the standard operating procedures used by the U.S. Geological Survey’s Noble Gas Laboratory in Denver, Colorado, U.S.A., for the measurement of dissolved gases (methane, nitrogen, oxygen, and carbon dioxide) and noble gas isotopes (helium-3, helium-4, neon-20, neon-21, neon-22, argon-36, argon-38, argon-40, kryton-84, krypton-86, xenon-103, and xenon-132) dissolved in water. A synopsis of the instrumentation used, procedures followed, calibration practices, standards used, and a quality assurance and quality control program is presented. The report outlines the day-to-day operation of the Residual Gas Analyzer Model 200, Mass Analyzer Products Model 215–50, and ultralow vacuum extraction line along with the sample handling procedures, noble gas extraction and purification, instrument measurement procedures, instrumental data acquisition, and calculations for the conversion of raw data from the mass spectrometer into noble gas concentrations per unit mass of water analyzed. Techniques for the preparation of artificial dissolved gas standards are detailed and coupled to a quality assurance and quality control program to present the accuracy of the procedures used in the laboratory.

Techniques and Methods↗
USGS2007

Landbird Monitoring Protocol for National Parks in the North Coast and Cascades Network

This protocol narrative outlines the rationale, sampling design and methods for monitoring landbirds in the North Coast and Cascades Network (NCCN) during the breeding season. The NCCN, one of 32 networks of parks in the National Park System, comprises seven national park units in the Pacific Northwest, including three large, mountainous, natural area parks (Mount Rainier [MORA] and Olympic [OLYM] National Parks, North Cascades National Park Service Complex [NOCA]), and four small historic cultural parks (Ebey's Landing National Historical Reserve [EBLA], Lewis and Clark National Historical Park [LEWI], Fort Vancouver National Historical Park [FOVA], and San Juan Island National Historical Park [SAJH]). The protocol reflects decisions made by the NCCN avian monitoring group, which includes NPS representatives from each of the large parks in the Network as well as personnel from the U.S. Geological Survey Forest and Rangeland Ecosystem Science Center (USGS-FRESC) Olympic Field Station, and The Institute for Bird Populations, at meetings held between 2000 (Siegel and Kuntz, 2000) and 2005. The protocol narrative describes the monitoring program in relatively broad terms, and its structure and content adhere to the outline and recommendations developed by Oakley and others (2003) and adopted by NPS. Finer details of the methodology are addressed in a set of standard operating procedures (SOPs) that accompany the protocol narrative. We also provide appendixes containing additional supporting materials that do not clearly belong in either the protocol narrative or the standard operating procedures.

Techniques and Methods↗
USGS1983

Meteorological, water-temperature, and discharge data for the Mattole River basin, Humboldt County, California

To overcome a major difficulty in the testing of the validity of river-temperature models - the lack of adequate precise synoptic data for an entire river basin - synoptic meteorologic, water-temperature, and discharge data were obtained in the Mattole River Basin in northern California during the period June 10 through August 31, 1975. The variables monitored were water temperature in the main channel and major tributaries, wind velocity, wet-bulb and dry-bulb air temperature, total hemispherical incoming radiation, total incoming shortwave radiation, discharge in the main channel and major tributaries, and average velocity and axial dispersion coefficients in the main channel. This report describes the experimental design and the instrumentation and procedures followed to insure the best possible information, and it presents a detailed set of data which can be used in testing river-temperature models. (USGS)

California↗
USGS1994

Use of landsat thematic mapper data to identify crop types and estimate irrigated acreage, Uvalde and Medina counties, Texas, 1991

Landsat Thematic Mapper (TM) data were used to estimate that about 51,000 acres of crops were irrigated with water pumped from the Edwards aquifer in Uvalde and Medina Counties, Texas in 1991. Bands 2, 3,4, and 5 from a TM image for August 10,1991, were classified using the maximum-likelihood, unsupervised-classification procedure to identify the areas of crops irrigated in the two counties. Detailed vegetation distribution maps of two calibration sites in the study area, and boundaries of the areas probably irrigated in 1991, were used to interpret the results and to separate probable irrigated areas by county from the rest of the image. Areas calculated for irrigated crops were 31,000 acres for Uvalde County, about 35 percent less than the area calculated using Landsat multispectral scanner (MSS) data in 1989, and 20,000 acres for Medina County, about 13 percent less than in 1989, a total decrease of about 28 percent for the two counties. Quantities of water pumped from the Edwards aquifer to irrigate crops in 1991 were estimated as 65,000 acre-feet for Uvalde County and 18,000 acre-feet for Medina County, a total decrease of about 56 percent from the value calculated using crop acreages from MSS data for 1989. Differences were attributed primarily to greater precipitation in 1991 than in 1989, resulting in smaller irrigation water requirements and less supplemental irrigation in 1991. Differences between results from 1989 and 1991, and between results from Uvalde and Medina Counties in 1991, were attributed primarily to greater precipitation in 1991, particularly in Medina County. The total number of acres of irrigated crops estimated using Landsat TM data was about 9 percent lower in Uvalde County and about 13 percent lower in Medina County than the number of acres calculated from data reported by the U.S. Department of Agriculture, Agricultural Stabilization and Conservation Service (ASCS). The total quantity of water pumped from the Edwards aquifer for irrigation in the two counties in 1991, about 83,000 acre-feet, was about 5 percent greater than the quantity calculated from data reported by the ASCS.

Texas↗
USGS2019

Radiometric calibration of a non-imaging airborne spectrometer to measure the Greenland ice sheet surface

Methods to radiometrically calibrate a non-imaging airborne visible-to-shortwave infrared (VSWIR) spectrometer to measure the Greenland ice sheet surface are presented. Airborne VSWIR measurement performance for bright Greenland ice and dark bare rock/soil targets is compared against the MODerate resolution atmospheric TRANsmission (MODTRAN ® ) radiative transfer code (version 6.0), and a coincident Landsat 8 Operational Land Imager (OLI) acquisition on 29 July 2015 during an in-flight radiometric calibration experiment. Airborne remote sensing flights were carried out in northwestern Greenland in preparation for the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) laser altimeter mission. A total of nine science flights were conducted over the Greenland ice sheet, sea ice, and open-ocean water. The campaign's primary purpose was to correlate green laser pulse penetration into snow and ice with spectroscopic-derived surface properties. An experimental airborne instrument configuration that included a nadir-viewing (looking downward at the surface) non-imaging Analytical Spectral Devices (ASD) Inc. spectrometer that measured upwelling VSWIR (0.35 to 2.5 µ m) spectral radiance ( W m - 2 sr - 1 µ m - 1 "> W m − 2 sr − 1 µ m − 1 ) in the two-color Slope Imaging Multi-polarization Photon-Counting Lidar's (SIMPL) ground instantaneous field of view, and a zenith-viewing (looking upward at the sky) ASD spectrometer that measured VSWIR spectral irradiance (W m −2 nm −1 ) was flown. National Institute of Standards and Technology (NIST) traceable radiometric calibration procedures for laboratory, in-flight, and field environments are described in detail to achieve a targeted VSWIR measurement requirement of within 5 % to support calibration/validation efforts and remote sensing algorithm development. Our MODTRAN predictions for the 29 July flight line over dark and bright targets indicate that the airborne nadir-viewing spectrometer spectral radiance measurement uncertainty was between 0.6 % and 4.7 % for VSWIR wavelengths (0.4 to 2.0 µ m) with atmospheric transmittance greater than 80 %. MODTRAN predictions for Landsat 8 OLI relative spectral response functions suggest that OLI is measuring 6 % to 16 % more top-of-atmosphere (TOA) spectral radiance from the Greenland ice sheet surface than was predicted using apparent reflectance spectra from the nadir-viewing spectrometer. While more investigation is required to convert airborne VSWIR spectral radiance into atmospherically corrected airborne surface reflectance, it is expected that airborne science flight data products will contribute to spectroscopic determination of Greenland ice sheet surface optical properties to improve understanding of their potential influence on ICESat-2 measurements.

Atmospheric Measurement Techniques↗
USGS2008

Weather and Climate Monitoring Protocol, Channel Islands National Park, California

Weather and climate are strong drivers of population dynamics, plant and animal spatial distributions, community interactions, and ecosystem states. Information on local weather and climate is crucial in interpreting trends and patterns in the natural environment for resource management, research, and visitor enjoyment. This document describes the weather and climate monitoring program at the Channel Islands National Park (fig. 1), initiated in the 1990s. Manual and automated stations, which continue to evolve as technology changes, are being used for this program. The document reviews the history of weather data collection on each of the five Channel Islands National Park islands, presents program administrative structure, and provides an overview of procedures for data collection, archival, retrieval, and reporting. This program overview is accompanied by the 'Channel Islands National Park Remote Automated Weather Station Field Handbook' and the 'Channel Islands National Park Ranger Weather Station Field Handbook'. These Handbooks are maintained separately at the Channel Island National Park as 'live documents' that are updated as needed to provide a current working manual of weather and climate monitoring procedures. They are available on request from the Weather Program Manager (Channel Islands National Park, 1901 Spinnaker Dr., Ventura, CA 93001; 805.658.5700). The two Field Handbooks describe in detail protocols for managing the four remote automated weather stations (RAWS) and the seven manual Ranger Weather Stations on the islands, including standard operating procedures for equipment maintenance and calibration; manufacturer operating manuals; data retrieval and archiving; metada collection and archival; and local, agency, and vendor contracts.

Techniques and Methods↗
USGS1990

Statistical inference for capture-recapture experiments

This monograph presents a detailed, practical exposition on the design, analysis, and interpretation of capture-recapture studies. The Lincoln-Petersen model (Chapter 2) and the closed population models (Chapter 3) are presented only briefly because these models have been covered in detail elsewhere. The Jolly- Seber open population model, which is central to the monograph, is covered in detail in Chapter 4. In Chapter 5 we consider the "enumeration" or "calendar of captures" approach, which is widely used by mammalogists and other vertebrate ecologists. We strongly recommend that it be abandoned in favor of analyses based on the Jolly-Seber model. We consider 2 restricted versions of the Jolly-Seber model. We believe the first of these, which allows losses (mortality or emigration) but not additions (births or immigration), is likely to be useful in practice. Another series of restrictive models requires the assumptions of a constant survival rate or a constant survival rate and a constant capture rate for the duration of the study. Detailed examples are given that illustrate the usefulness of these restrictions. There often can be a substantial gain in precision over Jolly-Seber estimates. In Chapter 5 we also consider 2 generalizations of the Jolly-Seber model. The temporary trap response model allows newly marked animals to have different survival and capture rates for 1 period. The other generalization is the cohort Jolly-Seber model. Ideally all animals would be marked as young, and age effects considered by using the Jolly-Seber model on each cohort separately. In Chapter 6 we present a detailed description of an age-dependent Jolly-Seber model, which can be used when 2 or more identifiable age classes are marked. In Chapter 7 we present a detailed description of the "robust" design. Under this design each primary period contains several secondary sampling periods. We propose an estimation procedure based on closed and open population models that allows for heterogeneity and trap response of capture rates (hence the name robust design). We begin by considering just 1 age class and then extend to 2 age classes. When there are 2 age classes it is possible to distinguish immigrants and births. In Chapter 8 we give a detailed discussion of the design of capture-recapture studies. First, capture-recapture is compared to other possible sampling procedures. Next, the design of capture-recapture studies to minimize assumption violations is considered. Finally, we consider the precision of parameter estimates and present figures on proportional standard errors for a variety of initial parameter values to aid the biologist about to plan a study. A new program, JOLLY, has been written to accompany the material on the Jolly-Seber model (Chapter 4) and its extensions (Chapter 5). Another new program, JOLLYAGE, has been written for a special case of the age-dependent model (Chapter 6) where there are only 2 age classes. In Chapter 9 a brief description of the different versions of the 2 programs is given. Chapter 10 gives a brief description of some alternative approaches that were not considered in this monograph. We believe that an excellent overall view of capture- recapture models may be obtained by reading the monograph by White et al. (1982) emphasizing closed models and then reading this monograph where we concentrate on open models. The important recent monograph by Burnham et al. (1987) could then be read if there were interest in the comparison of different populations.

Book↗
USGS2024

Earthquake-triggered ground-failure inventory associated with the M7.1 2018 Southcentral Alaska earthquake

The 30 November 2018, magnitude (Mw) 7.1 earthquake in Southcentral Alaska triggered substantial landslides, liquefaction, and ground cracking throughout the region, resulting in widespread geotechnical damage to buildings and infrastructure. Despite a challenging reconnaissance and remote-sensing environment, we constructed a detailed digital inventory of ground failure associated with the event from several sources. Sources included information derived from remotely sensed data, and data compiled from literature, social media postings, and earthquake damage information compiled by local, state, and federal agencies. Each instance of ground failure within the inventory contains information on the location and type of observed ground failure, and the methods and data used to document the occurrence. Where high-quality data, such as LIDAR or satellite imagery, were available and showed the ground-failure instance clearly, the extent is mapped as a polygon or polyline. All other locations are mapped as points. There are a total of 886 ground-failure instances documented within the inventory (400 landslides, 286 liquefaction features, and 200 features unattributed to specific processes). A semi-quantitative confidence scheme is used to describe mapping certainty associated with each ground-failure feature. This inventory represents a relatively moderate ground-failure-triggering event that occurred in a subarctic environment. This data paper describes the content within the inventory, the inventory data collection procedures, and limitations of the data. Events of this type are not often documented in detail; thus, adding the inventory data to the US Geological Survey Open Repository of Earthquake-Triggered Ground-Failure Inventories further diversifies the datasets available to the scientific community to be used to better understand and model earthquake-triggered ground failure.

Alaska↗
USGS2005

Sampling protocol for monitoring abiotic and biotic characteristics of mountain ponds and lakes

This document describes field techniques and procedures used for sampling mountain ponds and lakes. These techniques and procedures will be used primarily to monitor, as part of long-term programs in National Parks and other protected areas, the abiotic and biotic characteristics of naturally occurring permanent montane lentic systems up to 75 ha in surface area. However, the techniques and procedures described herein also can be used to sample temporary or ephemeral montane lentic sites. Each Standard Operating Procedure (SOP) section addresses a specific component of the limnological investigation, and describes in detail field sampling methods pertaining to parameters to be measured for each component.

Techniques and Methods↗
USGS2005

Quality-assurance plan for the analysis of fluvial sediment by the U.S. Geological Survey Kentucky Water Science Center Sediment Laboratory

This report describes laboratory procedures used by the U.S. Geological Survey Kentucky Water Science Center Sediment Laboratory for the processing and analysis of fluvial-sediment samples for concentration of sand and finer material. The report details the processing of a sediment sample through the laboratory from receiving the sediment sample, through the analytical process, to compiling results of the requested analysis. Procedures for preserving sample integrity, calibrating and maintaining of laboratory and field instruments and equipment, analyzing samples, internal quality assurance and quality control, and validity of the sediment-analysis results also are described. The report includes a list of references cited and a glossary of sediment and quality-assurance terms.

Open-File Report↗
USGS2006

Quality-assurance plan for the analysis of fluvial sediment by the U.S. Geological Survey New Mexico Water Science Center Sediment Laboratory

This report describes laboratory procedures used by the U.S. Geological Survey New Mexico Water Science Center Sediment Laboratory for the processing and analysis of fluvial-sediment samples for concentration of sand and finer material. The report details the processing of a sediment sample through the laboratory from receiving the sediment sample, through the analytical process, to compiling results of the requested analysis. Procedures for preserving sample integrity, calibrating and maintaining of laboratory and field instruments and equipment used to analyze samples, internal quality assurance and quality control, and validity of the sediment-analysis results also are described. The report includes a list of references cited and a glossary of sediment and quality-assurance terms.

Open-File Report↗
USGS2010

A two-step procedure for calculating earthquake hypocenters at Augustine Volcano: Chapter 7 in The 2006 Eruption of Augustine Volcano, Alaska

This chapter describes a two-step technique for determining earthquake hypocenters at Augustine Volcano. The algorithm, which was originally developed in the mid-1970s, was designed both to overcome limitations in the standard earthquake-location programs available at the time and to take advantage of the detailed seismic-velocity information obtained at Augustine Volcano. Hypocenters are calculated on the basis of a two-dimensional (2D) ray-tracing procedure that accounts for in plane lateral discontinuities within the seismic velocity structure. This algorithm calculates the minimum P- and S-wave travel time between theoretical grid points embedded in the velocity structure to each station in the seismic network. Station corrections that account for the differences between the model and actual velocity structure are derived from a time-term analysis of the 1975 active-source seismic experiment. Each relocated hypocenter is assigned to the grid point with the lowest rms residual between observed and calculated arrival times. Statistical techniques are used to assess the effect of random errors in P-wave-arrival determination on hypocentral location. These tests suggest that the 2D ray-tracing procedure presented here is able to resolve earthquake hypocenter depths to within 0.25 km between the volcano's summit and sea level and within 0.5 km from sea level to depths of 2 km below sea level.

Alaska↗
USGS1971

Interstitial water studies on small core samples, deep sea drilling Project, leg 7

The sediments cored on Leg 7 are predominantly deep sea biogenic oozes and chalks; only rarely were significant quantities of pelagic clays and volcanic detritus encountered. The biogenic sections include both siliceous and calcareous deposits. At three sites the drilling terminated in basalt, one of which (Site 62) is interpreted as being intrusive on the basis of intense alteration of the overlying sediment. With the exception of Ca++ and Sr , compositional changes in the pore waters are characteristically small relative to those reported previously for rapidly deposited, non-biogenic sediments. Ca++ and Sr + , however, exhibit concentrations of up to three times and ten times, respectively, those found in sea water. In several instances, constant concentration gradients as a function of depth have been found. The sampling, storage and analytical procedures employed have been briefly described in an earlier report (Sayles et al, 1970) and are detailed in a manuscript in preparation (Manheim and Chan). Sodium has been calculated as the difference between the summation of the anions and the summation of the major cations exclusive of sodium; to date, this method has proven more accurate than direct analytical methods. Agreement between the two types of silica determination used (emission spectrometric and colorimetric) is poor; the values obtained by emission spectrometry are characteristically higher. The colorimetric technique measures only "reactive" silica (monomeric and possibly dimeric) while the emission spectrometric technique will determine all of the silica in solution and in suspension. The silica content of most of the solutions is high (60 ppm) and polymerization is likely. We are currently investigating this discrepancy. The pH and water content data reported were obtained aboard the Glomar Challenger immediately after sampling

Initial reports of the Deep Sea Drilling Project↗