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At least 793 records · Page 44Linked to original sources
USGS2014

Offshore pelagic fish community

Lake Ontario’s offshore zone, as defined by Stewart et al. (2013), comprises all waters of the lake where the bottom depth is greater than 15 m excluding those in embayments. When the lake is thermally stratified during June-October, the offshore pelagic zone includes the upper-warm and middle-cool layers of water which serve as important habitat for Alewife and other prey fishes, and for predators like salmon and trout. Early changes in the fish community of the offshore pelagic zone are well documented elsewhere (e.g., Smith 1972; Christie 1973) as are more recent changes (e.g., Owens et al. 2003; Mills et al. 2003). Currently the offshore fish community consists of a mix of native and non-native species. Native species are those that were present prior to European colonization and for the offshore pelagic zone, include predators like Atlantic Salmon and prey fish like Cisco, Emerald Shiner, and Threespine Stickleback. Non-native species are those that were introduced unintentionally like Alewife and Rainbow Smelt, or that were introduced intentionally like Chinook Salmon, Coho Salmon, Rainbow Trout, and Brown Trout. Non-native salmon and trout were introduced originally by fisheries managers to provide fishing opportunities and later to reduce an overabundance of Alewife. Alewife is the most abundant prey fish in the offshore pelagic zone and it dominates the diets of native and introduced predators (Brandt 1986; Lantry 2001). Alewife can have direct and indirect negative effects on other fishes through competition for food and/or predation on their larvae (Madenjian et al. 2008). Alewife also contain thiaminase, an enzyme that catalyzes the breakdown of thiamine, and fish that eat mainly Alewife can become thiamine deficient which impairs their reproduction (Honeyfield et al. 2005). Except for that of the Alewife, prey fish populations in the offshore pelagic zone are depressed, and not large enough to sustain the zone’s predators. Alewife remain necessary for a functional ecosystem that is required to sustain a highly-valued, trophy sport fishery (Stewart et al. 2013). Wild production of trout and salmon occurs in Lake Ontario tributaries, contributing to in-lake populations (Rand et al. 1993; Connerton et al. 2009; Connerton et al. 2014c). Stocking hatchery-reared fish (Fig. 1), however, remains an essential tool for managing Lake Ontario’s diverse trout and salmon fisheries and achieving the Offshore Pelagic Zone Goal (Stewart et al. 2013): Maintain the offshore pelagic fish community, that is characterized by a diversity of trout and salmon species including Chinook Salmon, Coho Salmon, Rainbow Trout, Brown Trout, and Atlantic Salmon, in balance with prey-fish populations and lower trophic levels. Here we review the fish-community objectives (FCOs) for Lake Ontario’s offshore pelagic zone (Stewart et al. 2013) and evaluate whether those objectives were met during this reporting period (2008-2013) by assessing the status of the objectives’ indicators. We also compare the status of indicators in this reporting period with those in the previous reporting period (2003-2007) (Connerton et al. 2014b). Specific objectives are in italics at the start of each major section and associated indicators of progress are given in Progress and Outlook subsections.

Lake Ontario↗
USGS2024

A latest Pleistocene and Holocene composite tephrostratigraphic framework for northeastern North America

Lakes and bogs in northeastern North America preserve tephra deposits sourced from multiple volcanic systems in the Northern Hemisphere. However, most studies of these deposits focus on specific Holocene intervals and the latest Pleistocene, providing snapshots rather than a full picture. We combine new data with previous work, supplemented by a broad review of the characteristics and ages of potential source regions and volcanoes, to develop the first composite tephrostratigraphic framework covering the last ~14,000 years for this region. We report new cryptotephra records from three ombrotrophic peat bogs—Irwin Smith (Michigan), Bloomingdale (New York), and Sidney Bog (Maine)—as well as new analyses and age models from previously reported sites, Nordan’s Pond Bog (Newfoundland) and Thin-Ice Pond (Nova Scotia). A new tephra (Iliinsky) from the NGRIP and GRIP ice cores is also presented as it can be correlated to new data from these terrestrial records and helps validate radiocarbon age models. We identify 21 new tephra in addition to the 15 already known, several of which cover the entire region – the White River Ash east, Newberry Pumice, Ruppert (NDN230), and Mazama. For the first time we find Mount St. Helens Yn (ca. 3660 cal yr BP) and a set P tephra (~3000–2550 cal yr BP), and confirm the presence of Jala Pumice from Volcan Ceboruco, Mexico, and KS1 from Ksudach volcano, Kamchatka. We describe new “ultra-distal” tephra, including the early Holocene KS 2 eruption, and propose correlations to volcanoes Iliinsky and Shiveluch of Kamchatka, and Ushishir of the Kurile Islands. Not all of these tephra represent large eruptions, with several plausible correlations to sub-Plinian events. Using Bayesian age-modeling, we present new age estimates for the newly described tephra, for tephra with previously poor age control, and for several proximal correlatives. Overall, we demonstrate northeastern North America’s importance for providing transcontinental linkages between paleoenvironmental records and providing insights into ash distribution from different styles and sizes of eruptions.

northeastern North America↗
USGS2006

Estimating landslide losses - preliminary results of a seven-State pilot project

Introduction: In 2001, the U.S. Geological Survey Landslide Hazards Program provided funding for seven State geological surveys to report on the status of landslide investigation strategies in each of their States, and to suggest improved ways to approach the tracking of landslides, their effects, losses associated with the landslides, and hazard mitigation strategies. Each State was to provide a draft report suggesting innovative ways to track landslides, and to participate in subsequent workshops. A workshop was convened in June 2003 in Lincoln, Neb., to discuss the results and future strategies on how best to incorporate the seven pilot projects into one methodology that all of the 50 States could adopt. The seven individual reports produced by the State surveys are published here to put forth a forum for discussion of the varying methods of tracking landslides. The goal is to eventually adopt a single, universally applied methodology to track landslides that will provide a consistent framework for collecting data on landslide damage and economic impact. Participating States include: California (James Davis, Jack McMillan); Kentucky (Jim Cobb, John Kiefer, John Rockaway); Nebraska (Mark Kuzila, Duane Eversoll); Ohio (Thomas Berg, Jon Rockaway), Oregon (John Beaulieu, Yumei Wang, Renee Summers, Jon Hofmeister); Pennsylvania (Jay Parrish, Helen Delano); Utah (Richard Allis, Francis Ashland). The USGS personnel involved in the planning and meeting facilitation are Paula Gori, Peter Lyttle, and John Pallister. The general USGS strategy to address landslide loss reduction was developed with input from State geological surveys, the engineering-geology consulting community, and academic investigators. The strategy was reviewed by the National Research Council, 2004), is summarized in USGS Circular 1244 (Spiker and Gori, 2003) and is endorsed by the AASG. This pilot study, conducted by seven State geological surveys, examines the feasibility of collecting accurate and reliable information on economic losses associated with landslides. Each State survey examined the availability, distribution, and inherent uncertainties of economic loss data in their study areas. Their results provide the basis for identifying the most fruitful methods of collecting landslide loss data nationally, using methods that are consistent and provide common goals. These results can enhance and establish the future directions of scientific investigation priorities by convincingly documenting landslide risks and consequences that are universal throughout the 50 States. This report is organized as follows: A general summary of the pilot project history, goals, and preliminary conclusions from the Lincoln, Neb. workshop are presented first. Internet links are then provided for each State report, which appear on the internet in PDF format and which have been placed at the end of this open-file report. A reference section follows the reports, and, lastly, an Appendix of categories of landslide loss and sources of loss information is included for the reader's information. Please note: The Oregon Geological Survey has also submitted a preliminary report on indirect loss estimation methodology, which is also linked with the others. Each State report is unique and presented in the form in which it was submitted, having been independently peer reviewed by each respective State survey. As such, no universal 'style' or format has been adopted as there have been no decisions on which inventory methods will be recommended to the 50 states, as of this writing. The reports are presented here as information for decision makers, and for the record; although several reports provide recommendations on inventory methods that could be adopted nationwide, currently no decisions have been made on adopting a uniform methodology for the States.

Open-File Report↗
USGS2023

Blue snowflakes in a warming world: Karner blue butterfly climate change vulnerability synthesis and best practices for adaptation

This report—developed at the request of the United States Fish and Wildlife Service-led Karner Blue Butterfly Recovery Team by Recovery Team members and partners—provides a Karner blue butterfly climate change vulnerability synthesis, explores a range of potential responses, and presents best practices for climate change-informed conservation of the species. The three decades since the Karner blue butterfly’s (Lycaeides [Plebejus] melissa samuelis Nabokov) listing as federally endangered in the United States have seen a diverse and dedicated research and management community coalesce around the species’ recovery. This geographically expansive conservation collaboration has broken new ground for threatened and endangered species recovery. Many Karner blue recovery areas are making steady progress towards recovery goals, but some are not. An extremely hot and dry 2012, perhaps aided by adverse longer-term climate trends such as declining snow cover, extirpated the Karner blue from Indiana Dunes National Park and the surrounding Indiana Dunes Karner Blue Butterfly Recovery Unit—the southernmost recovery unit and once host to one of the species’ largest populations—as well as from northwest Ohio. Because of the fundamental challenge that climate change represents to Karner blue butterfly recovery and of the general need for endangered species conservation plans to better address climate change, the United States Fish and Wildlife Service-led Karner Blue Butterfly Recovery Team tasked a subset of the team to: Explore the species’ climate change sensitivity and adaptive capacity, review ongoing and projected climate change across the Karner blue range and associated uncertainties, and develop and suggest best practices concerning long-term adaptation strategies. Consistent with that mandate, this report synthesizes what is known about Karner blue climate change vulnerability and applies current thinking in climate change adaptation to help foster strategic, long-term, climate change-informed Karner blue recovery and conservation. It develops and explores a range of potential climate change-informed butterfly- and habitat-stewardship responses, using the resist-accept-direct (RAD) framework to foster a broad range of approaches, and provides guidance regarding how they may be pursued. The report also provides suggestions for improving the climate change-exposure component of Karner blue vulnerability assessment.

Natural Resource Report↗
USGS1989

Subsurface-water flow and solute transport: federal glossary of selected terms

The purpose of this report is to provide a glossary of selected terms for saturated and unsaturated flow and related processes involved in transport of contaminants in the subsurface. The glossary contains five tables. Table 1 is a list of parameters with associated symbols and units. Tables 2 to 5 are conversion charts. The original manuscript was prepared by Thomas J. Nicholson, U.S. Nuclear Regulatory Commission. It was subsequently examined by the Ground-Water Glossary Working Group and experts within and outside the Federal Government, whose recommendations were accommodated where appropriate in the glossary. It is hoped that the glossary will aid in the communications between soil scientists, hydrologists, and hydrogeologists. The terms defined in the glossary were selected after an extensive survey of glossaries and reports in the areas of (1) ground-water geology, hydraulics, and chemistry, (2) soil-water physics and chemistry, (3) contaminant transport, (4) unsaturated-zone hydrology, (5) chemistry and transport of solutes, and (6) ground-water quality. Some of the definitions have been modified for clarity from a variety of technical sources. Where more than one definition appears for the selected term, the first one was determined by the working group to be the most appropriate general definition, followed by other, more specialized, definitions. Some terms and definitions are not currently in use by all agencies; however, they are included in the glossary because they can be found in the literature. The reader is encouraged to consult with the original source cited for more explanatory comments. Additional regulatory definitions, which are underlined and are taken directly from the Code of Federal Regulations (CFR) and Federal laws (USC), were added following review by the various Federal agencies in May 1986. The definitions and conversion charts are from two principal sources provided herein. The first is the 11Glossary11 compiled by A. I. Johnson in the 1981 report by the American Society of Testing and Materials titled Permeability and Groundwater Contaminant Transport. The second is Manu a 1 40, 11Ground-water Management, 11 produced by the American Society of Civil Engineers in 1985.

Report↗
USGS2018

Critically assessing the utility of portable lead analyzers for wildlife conservation

Lead (Pb) exposure in wildlife is a widespread management and conservation concern. Quantitative determination of Pb concentrations in wildlife tissues is the foundation for estimating exposure and risk. Development of low‐cost, portable instruments has improved access and cost‐effectiveness of determining Pb concentrations in blood samples, while also facilitating the ability for wildlife researchers to conduct near real‐time Pb testing. However, these instruments, which use anodic stripping voltammetry (ASV) methodology, may produce an analytical bias in wildlife‐blood Pb concentrations. Additionally, their simplicity invites use without appropriate quality‐assurance–quality‐control measures. Together, these factors can reduce data quality and hamper the ability to evaluate it, raising concerns about use of these instruments to inform important conservation issues. We document the extent to which this bias is addressed in the wildlife toxicology literature, develop quantitative approaches for correcting the bias, and provide recommendations to ensure robust data quality when using these instruments. Of the 25 studies we reviewed that referenced ASV use for determining Pb exposure in wildlife, only 32% acknowledged the existence of bias from the instrument. Importantly, another 20% of the studies actually reported ASV and spectroscopic‐based results together without acknowledging their lack of equivalence. Using a multispecies data set of avian blood Pb concentrations, we found that ASV‐based estimates of paired blood Pb concentrations were 30–38% lower than those from standard spectrometric‐based methods. We provide regression equations based on this analysis of 453 blood samples to allow users of ASV instruments to adjust Pb concentrations to spectrometric‐equivalent values, and propose a series of guidelines to follow when using these instruments to improve data validity.

Wildlife Society Bulletin↗
USGS2009

The geology of Hotei Regio, Titan: Correlation of Cassini VIMS and RADAR

Joint Cassini VIMS and RADAR SAR data of ∼700-km-wide Hotei Regio reveal a rich collection of geological features that correlate between the two sets of images. The degree of correlation is greater than anywhere else seen on Titan. Central to Hotei Regio is a basin filled with cryovolcanic flows that are anomalously bright in VIMS data (in particular at 5 μm) and quite variable in roughness in SAR. The edges of the flows are dark in SAR data and appear to overrun a VIMS-bright substrate. SAR-stereo topography shows the flows to be viscous, 100–200 m thick. On its southern edge the basin is ringed by higher (∼1 km) mountainous terrain. The mountains show mixed texture in SAR data: some regions are extremely rough, exhibit low and spectrally neutral albedo in VIMS data and may be partly coated with darker hydrocarbons. Around the southern margin of Hotei Regio, the SAR image shows several large, dendritic, radar-bright channels that flow down from the mountainous terrain and terminate in dark blue patches, seen in VIMS images, whose infrared color is consistent with enrichment in water ice. The patches are in depressions that we interpret to be filled with fluvial deposits eroded and transported by liquid methane in the channels. In the VIMS images the dark blue patches are encased in a latticework of lighter bands that we suggest to demark a set of circumferential and radial fault systems bounding structural depressions. Conceivably the circular features are tectonic structures that are remnant from an ancient impact structure. We suggest that impact-generated structures may have simply served as zones of weakness; no direct causal connection, such as impact-induced volcanism, is implied. We also speculate that two large dark features lying on the northern margin of Hotei Regio could be calderas. In summary the preservation of such a broad suite of VIMS infrared color variations and the detailed correlation with features in the SAR image and SAR topography evidence a complex set of geological processes (pluvial, fluvial, tectonic, cryovolcanic, impact) that have likely remained active up to very recent geological time (<10 4 year). That the cryovolcanic flows are excessively bright in the infrared, particularly at 5 μm, might signal ongoing geological activity. One study [Nelson, R.M., and 28 colleagues, 2009. Icarus 199, 429–441] reported significant 2-μm albedo changes in VIMS data for Hotei Arcus acquired between 2004 and 2006, that were interpreted as evidence for such activity. However in our review of that work, we do not agree that such evidence has yet been found.

Icarus↗
USGS2012

Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope

The results of short-duration formation tests in northern Alaska and Canada have further documented the energy-resource potential of gas hydrates and have justified the need for long-term gas-hydrate-production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally occurring gas hydrate to depressurization-induced or thermal-, chemical-, or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gashydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas-hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with the US Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk River, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas-hydrate-production test sites. The test-site-assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas-hydrate testing. The site-selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas-hydrate-production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area and provides new information on the nature of gas-hydrate occurrence and the potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well-log analysis, geological correlation and mapping, and numerical simulation.

Alaska↗
USGS2018

Using the value of information to improve conservation decision making

Conservation decisions are challenging, not only because they often involve difficult conflicts among outcomes that people value, but because our understanding of the natural world and our effects on it is fraught with uncertainty. Value of Information (VoI) methods provide an approach for understanding and managing uncertainty from the standpoint of the decision maker. These methods are commonly used in other fields (e.g., economics, public health) and are increasingly used in biodiversity conservation. This decision analytical approach can identify the best management alternative to select where the effectiveness of interventions is uncertain, and can help to decide when to act and when to delay action until after further research. We review the use of VoI in the environmental domain, reflect on the need for greater uptake of VoI, particularly for strategic conservation planning, and suggest promising areas for new research. We also suggest common reporting standards as a means of increasing the leverage of this powerful tool. The environmental science, ecology and biodiversity categories of the Web of Knowledge were searched using the terms ‘Value of Information,’ ‘Expected Value of Perfect Information,’ and the abbreviation ‘EVPI.’ Google Scholar was searched with the same terms, and additionally the terms decision and biology, biodiversity conservation, fish, or ecology. We identified 1225 papers from these searches. Included studies were limited to those that show an application of VoI in biodiversity conservation rather than simply describing the method. All examples of use of VOI were summarised regarding the application of VoI, the management objectives, the uncertainties, models used, how the objectives were measured, and the type of VoI. While the use of VoI appears to be on the increase in biodiversity conservation, the reporting of results is highly variable, which can make it difficult to understand the decision context and which uncertainties were considered. Moreover, it was unclear if, and how, the papers informed management and policy interventions, which is why we suggest a range of reporting standards that would aid the use of VoI. The use of VoI in conservation settings is at an early stage. There are opportunities for broader applications, not only for species-focussed management problems, but also for setting local or global research priorities for biodiversity conservation, making funding decisions, or designing or improving protected area networks and management. The long-term benefits of applying VoI methods to biodiversity conservation include a more structured and decision-focused allocation of resources to research.

Biological Reviews↗
USGS2019

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report

The Wyoming Landscape Conservation Initiative (WLCI) was established in 2008 to address the scientific and conservation questions associated with land use changes because of energy development and other factors in southwest Wyoming. Over the past decade, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (defined here as more than 10 years), science-based program that assesses and enhances the quality and quantity of wildlife habitats in this region while facilitating responsible development. The USGS Science Team completes scientific research and develops tools that inform and support WLCI partner planning, decision making, and on-the-ground management actions. In fiscal year 2017, USGS published 18 products (including peer-reviewed journal articles, USGS series publications, and data releases), prepared an additional 7 products for publication, and presented 14 talks or posters at professional scientific meetings in addition to numerous informal presentations to WLCI partners at meetings and workshops. In this report, we summarize the science themes that describe USGS science for the WLCI and highlight work completed in fiscal year 2017 for each science theme. We also provide information on how USGS science is being used by land managers to better achieve habitat conservation objectives.

Wyoming↗
USGS1999

Water-quality variability in San Francisco Bay: general patterns of change during 1997

The 1997 Annual Report is the fifth Annual Report from the Regional Monitoring Program for Trace Substances (RMP) and contains a comprehensive description of RMP results from the 1997 monitoring year. As in previous years, the report includes results from the Base Program (water, sediment, and bivalve monitoring) and results from Pilot and Special Studies completed in 1997, in addition to an update on the RMP Five-Year Review implementation. It also includes papers contributed by RMP investigators and other scientists. These articles address related monitoring activities, and help to provide additional insight into contaminant patterns and the impacts of those contaminants on the San Francisco Estuary. The 1997 monitoring year proved to be an unusual one, with record-setting precipitation in December and January followed by unusually dry weather in February and March. These weather patterns had a visible effect on RMP results, frequently creating sharp contrasts in results between the first two sampling cruises of the year, and higher than normal contaminant concentrations at many RMP sampling sites in February. These results, and results from the other aspects of the RMP, are summarized below.

California↗
USGS2018

2018 report on incorporating sedimentary basin response into the design of tall buildings in Seattle, Washington

On March 22, 2018, the Seattle Department of Construction and Inspections (SDCI) and the U.S. Geological Survey (USGS) convened a workshop of engineers and seismologists to provide guidance on incorporating sedimentary basin response into the design of tall buildings in Seattle. This workshop provided recommendations that build on those from a March 2013 workshop (Chang and others, 2014), primarily based on new results from 3-D simulations of magnitude (M) 9 Cascadia earthquakes (The M9 Project). Susan Chang, a geotechnical engineer with the Seattle Department of Construction and Inspections, organized and led the workshop; Art Frankel (USGS) assisted in constructing the agenda. The workshop agenda and attendees are provided in the appendix. The attendees represented a wide range of expertise, including seismologists with expertise in ground motions and basin response, geotechnical engineers, and structural engineers. Their professional experience included working on local projects related to the design of long-period structures; peer reviewing ground motions for performance-based design of high-rises in Seattle; researching basin response in academic, government and industry settings; developing ground motion models; and representing local and national structural engineering organizations. In this report, we summarize the technical presentations, key discussion points, and recommendations from the workshop.

Washington↗
USGS1982

Guidelines for determining flood flow frequency: Bulletin #17B of the Hydrology Subcommittee

In December 1967, Bulletin No. 15, "A Uniform Technique for Determining Flood Flow Frequencies," was issued by the Hydrology Committee of the Water Resources Council. The report recommended use of the Pearson Type III distribution with log transformation of the data (log-Pearson Type III distribution) as a base method for flood flow frequency studies. As pointed out in that report, further studies were needed covering various aspects of flow frequency determinations. In March 1976, Bulletin 17, "Guidelines for Determining Flood Flow Frequency" was issued by the Water Resources Council. The guide was an extension and update of Bulletin No. 15. It provided a more complete guide for flood flow frequency analysis incorporating currently accepted technical methods with sufficient detail to promote uniform application. It was limited to defining flood potentials in terms of peak discharge and exceedance probability at locations where a systematic record of peak flood flows is available. The recommended set of procedures was selected from those used or described in the literature prior to 1976, based on studies conducted for this purpose at the Center for Research in Water Resources of the University of Texas at Austin (summarized in Appendix 14) and on studies by the Work Group on Flood Flow Frequency. The "Guidelines" were revised and reissued in June 1977 as Bulletin 17A. Bulletin 17B is the latest effort to improve and expand upon the earlier publications. Bulletin 17B provides revised procedures for weighting a station skew value with the results from a generalized skew study, detecting and treating outliers, making two station comparisons, and computing confidence limits about a frequency curve. The Work Group that prepared this revision did not address the suitability of the original distribution or the generalized skew map. Major problems are encountered when developing guides for flood flow frequency determinations. There is no procedure or set of procedures that can be adopted which, when rigidly applied to the available data, will accurately define the flood potential of any given watershed. Statistical analysis alone will not resolve all flood frequency problems. As discussed in subsequent sections of this guide, elements of risk and uncertainty are inherent in any flood frequency analysis. User decisions must be based on properly applied procedures and proper interpretation of results considering risk and uncertainty. Therefore, the judgment of a professional experienced in hydrologic analysis will enhance the usefulness of a flood frequency analysis and promote appropriate application. It is possible to standarize many elements of flood frequency analysis. This guide describes each major element of the process of defining the flood potential at a specific location in terms of peak discharge and exceedance probability. Use is confined to stations where available records are adequate to warrant statistical analysis of the data. Special situations may require other approaches. In those cases where the procedures of this guide are not followed, deviations must be supported by appropriate study and accompanied by a comparison of results using the recommended procedures. As a further means of achieving consistency and improving results, the Work Group recommends that studies be coordinated when more than one analyst is working currently on data for the same location. This recommendation holds particularly when defining exceedance probabilities for rare events, where this guide allows more latitude. Flood records are limited. As more years of record become available at each location, the determination of flood potential may change. Thus, an estimate may be outdated a few years after it is made. Additional flood data alone may be sufficient reason for a fresh assessment of the flood potential. When making a new assessment, the analyst should incorporate in his study a review of earlier estimates. Where differences appear, they should be acknowledged and explained.

Bulletin↗
USGS2013

Water resources and shale gas/oil production in the Appalachian Basin: critical issues and evolving developments

Unconventional natural gas and oil resources in the United States are important components of a national energy program. While the Nation seeks greater energy independence and greener sources of energy, Federal agencies with environmental responsibilities, state and local regulators and water-resource agencies, and citizens throughout areas of unconventional shale gas development have concerns about the environmental effects of high volume hydraulic fracturing (HVHF), including those in the Appalachian Basin in the northeastern United States (fig. 1). Environmental concerns posing critical challenges include the availability and use of surface water and groundwater for hydraulic fracturing; the migration of stray gas and potential effects on overlying aquifers; the potential for flowback, formation fluids, and other wastes to contaminate surface water and groundwater; and the effects from drill pads, roads, and pipeline infrastructure on land disturbance in small watersheds and headwater streams (U.S. Government Printing Office, 2012). Federal, state, regional and local agencies, along with the gas industry, are striving to use the best science and technology to develop these unconventional resources in an environmentally safe manner. Some of these concerns were addressed in U.S. Geological Survey (USGS) Fact Sheet 2009–3032 (Soeder and Kappel, 2009) about potential critical effects on water resources associated with the development of gas extraction from the Marcellus Shale of the Hamilton Group (Ver Straeten and others, 1994). Since that time, (1) the extraction process has evolved, (2) environmental awareness related to high-volume hydraulic fracturing process has increased, (3) state regulations concerning gas well drilling have been modified, and (4) the practices used by industry to obtain, transport, recover, treat, recycle, and ultimately dispose of the spent fluids and solid waste materials have evolved. This report updates and expands on Fact Sheet 2009–3032 and presents new information regarding selected aspects of unconventional shale gas development in the Appalachian Basin (primarily Virginia, West Virginia, Maryland, Pennsylvania, Ohio, and New York). This document was prepared by the USGS, in cooperation with the U.S. Department of Energy, and reviews the evolving technical advances and scientific studies made in the Appalachian Basin between 2009 and the present (2013), addressing past and current issues for oil and gas development in the region.

Maryl;New York;Ohio;Pennsylvania;Virginia;West Vir↗
USGS1969

The Geologic Story of Mount Rainier

Ice-clad Mount Rainier, towering over the landscape of western Washington, ranks with Fuji-yama in Japan, Popocatepeti in Mexico, and Vesuvius in Italy among the great volcanoes of the world. At Mount Rainier, as at other inactive volcanoes, the ever-present possibility of renewed eruptions gives viewers a sense of anticipation, excitement, and apprehension not equaled by most other mountains. Even so, many of us cannot imagine the cataclysmic scale of the eruptions that were responsible for building the giant cone which now stands in silence. We accept the volcano as if it had always been there, and we appreciate only the beauty of its stark expanses of rock and ice, its flower-strewn alpine meadows, and its bordering evergreen forests. Mount Rainier owes its scenic beauty to many features. The broad cone spreads out on top of a major mountain range - the Cascades. The volcano rises about 7,000 feet above its 7,000-foot foundation, and stands in solitary splendor - the highest peak in the entire Cascade Range. Its rocky ice-mantled slopes above timberline contrast with the dense green forests and give Mount Rainier the appearance of an arctic island in a temperate sea, an island so large that you can see its full size and shape only from the air. The mountain is highly photogenic because of the contrasts it offers among bare rock, snowfields, blue sky, and the incomparable flower fields that color its lower slopes, shadows cast by the multitude of cliffs, ridges, canyons, and pinnacles change constantly from sunrise to sunset, endlessly varying the texture and mood of the mountain. The face of the mountain also varies from day to day as its broad snowfields melt during the summer. The melting of these frozen reservoirs makes Mount Rainier a natural resource in a practical as well as in an esthetic sense, for it ensures steady flows of water for hydroelectric power in the region, regardless of season. Seen from the Puget Sound country to the west, Mount Rainier has an unreal quality - its white summit, nearly 3 miles high, seems to float among the clouds. We share with the populace of the entire lowland a thrill as we watch skyward the evening's setting sun reddens the volcano's western snowfields. When you approach the mountain in its lovely setting, you may find something that appeals especially to you - the scenery, the wildlife, the glaciers, or the wildflowers. Or you may feel challenged to climb to the summit. Mount Rainier and its neighboring mountains have a special allure for a geologist because he visualizes the event - some ordinary, some truly spectacular - that made the present landscape. Such is the fascination of geology. A geologist becomes trained to see 'in his mind's eye' geologic events of thousands or even millions of years ago. And, most remarkable, he can 'see' these events by studying rocks in a cliff or roadcut, or perhaps by examining earthy material that looks like common soil beneath pastureland many miles away from the volcano. Our key to understanding the geology of Mount Rainier is that each geologic event can be reconstructed - or imagined - from the rocks formed at the time of the event. With this principle as our guide, we will review the geologic ancestry of this majestic volcano and learn what is behind its scenery.

Washington↗