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

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At least 505 records · Page 28Linked to original sources
USGS2015

Aftershock communication during the Canterbury Earthquakes, New Zealand: Implications for response and recovery in the built environment

On 4 September 2010, a Mw7.1 earthquake occurred in Canterbury, New Zealand. Following the initial earthquake, an aftershock sequence was initiated, with the most significant aftershock being a Mw6.3 earthquake occurring on 22 February 2011. This aftershock caused severe damage to the city of Christchurch and building failures that killed 185 people. During the aftershock sequence it became evident that effective communication of aftershock information (e.g., history and forecasts) was imperative to assist with decision making during the response and recovery phases of the disaster, as well as preparedness for future aftershock events. As a consequence, a joint JCDR-USGS research project was initiated to investigate: • How aftershock information was communicated to organisations and to the public; • How people interpreted that information; • What people did in response to receiving that information; • What information people did and did not need; and • What decision-making challenges were encountered relating to aftershocks. Research was conducted by undertaking focus group meetings and interviews with a range of information providers and users, including scientists and science advisors, emergency managers and responders, engineers, communication officers, businesses, critical infrastructure operators, elected officials, and the public. The interviews and focus group meetings were recorded and transcribed, and key themes were identified. This paper focuses on the aftershock information needs for decision-making about the built environment post-earthquake, including those involved in response (e.g., for building assessment and management), recovery/reduction (e.g., the development of new building standards), and readiness (e.g. between aftershocks). The research has found that the communication of aftershock information varies with time, is contextual, and is affected by interactions among roles, by other information, and by decision objectives. A number of general and specific insights into improving the communication of aftershock information are provided.

Canterbury↗
USGS2005

Global land cover mapping and characterization: present situation and future research priorities

The availability and accessibility of global land cover data sets plays an important role in many global change studies. The importance of such science‐based information is also reflected in a number of international, regional, and national projects and programs. Recent developments in earth observing satellite technology, information technology, computer hardware and software, and infrastructure development have helped developed better quality land cover data sets. As a result, such data sets are increasingly becoming available, the user‐base is ever widening, application areas have been expanding, and the potential of many other applications are enormous. Yet, we are far from producing high quality global land cover data sets. This paper examines the progress in the development of digital global land cover data, their availability, and current applications. Problems and opportunities are also explained. The overview sets the stage for identifying future research priorities needed for operational land cover assessment and monitoring.

Geocarto International↗
USGS2006

Eutrophication of freshwater and marine ecosystems

Initial understanding of the links between nutrients and aquatic productivity originated in Europe in the early 1900s, and our knowledge base has expanded greatly during the past 40 yr. This explosion of eutrophication-related research has made it unequivocally clear that a comprehensive strategy to prevent excessive amounts of nitrogen and phosphorus from entering our waterways is needed to protect our lakes, rivers, and coasts from water quality deterioration. However, despite these very significant advances, cultural eutrophication remains one of the foremost problems for protecting our valuable surface water resources. The papers in this special issue provide a valuable cross section and synthesis of our current understanding of both freshwater and marine eutrophication science. They also serve to identify gaps in our knowledge and will help to guide future research.

Limnology and Oceanography↗
USGS1995

Planning long-term vegetation studies at landscape scales

Long-term ecological research is receiving more attention now than ever before. Two recent books, Long-term Studies in Ecology: Approaches and Alternatives , edited by Gene Likens (1989), and Long-term Ecological Research: An International Perspective , edited by Paul Risser (1991), prompt the question, “Why are these books so thin?” Except for data from paleoecological, retrospective studies (see below), there are exceptionally few long-term data sets in terrestrial ecology (Strayer et al. 1986; Tilman 1989; this volume). In a sample of 749 papers published in Ecology , Tilman (1989) found that only 1.7% of the studies lasted at least five field seasons. Only one chapter in each of the review books dealt specifically with expanding both the temporal and the spatial scales of ecological research (Berkowitz et al. 1989; Magnuson et al. 1991). Judging by the growing number of landscape-scale long-term studies, however, such as the Long-Term Ecological Research (LTER) Program (Callahan 1991), the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program (EMAP; Palmer et al. 1991), the U.S. Army’s Land Condition-Trend Analysis (LCTA) Program (Diersing et al. 1992), and various agencies’ global change research programs (CEES 1993), there is a growing interest to expand ecological research both temporally and spatially.

Book chapter↗
USGS2023

The Arctic Rivers Project: Using an equitable co-production framework for integrating meaningful community engagement and science to understand climate impacts

As the Arctic and its rivers continue to warm, a better understanding of the possible future impacts on people would benefit from close partnership with Indigenous communities and scientists from diverse fields of study. We present efforts by the Arctic Rivers Project to conduct community-engaged research to increase collective understanding of the historical and potential future impacts of climate change on rivers, fish, and Indigenous communities. Working in central to northern Alaska and the Yukon Territory in Canada, the project seeks to engage with Indigenous communities in ethical and equitable ways to produces science that is useful, useable, and used that may serve as an example for future research efforts. Toward this goal, we formed an Indigenous Advisory Council and together developed project-specific knowledge co-production protocols. This paper provides a novel model of design and implementation to co-produce knowledge with communities across a large study domain.

Alaska↗
USGS2010

Advances in the hydrogeochemistry and microbiology of acid mine waters

The last decade has witnessed a plethora of research related to the hydrogeochemistry and microbiology of acid mine waters and associated tailings and waste-rock waters. Numerous books, reviews, technical papers, and proceedings have been published that examine the complex bio-geochemical process of sulfide mineral oxidation, develop and apply geochemical models to site characterization, and characterize the microbial ecology of these environments. This review summarizes many of these recent works, and provides references for those investigating this field. Comparisons of measured versus calculated Eh and measured versus calculated pH for water samples from several field sites demonstrate the reliability of some current geochemical models for aqueous speciation and mass balances. Geochemical models are not, however, used to predict accurately time-dependent processes but to improve our understanding of these systems and to constrain possible processes that contribute to actual or potential water quality issues. Microbiological studies are demonstrating that there is much we have yet to learn about the types of different microorganisms and their function and ecology in mine-waste environments. A broad diversity of green algae, bacteria, archaea, yeasts, and fungi are encountered in acid mine waters, and a better understanding of their ecology and function may potentially enhance remediation possibilities as well as our understanding of the evolution of life.

International Geology Review↗
USGS1993

Toward the simulation of the effects of the Great Lakes on regional climate

This paper describes a set of numerical experiments aimed at evaluating the feasibility of applying a version of the National Center for Atmospheric Research-Pennsylvania State University regional model (MM4) to regional climate simulation over the Great Lakes Basin. The objectives of this initial modeling investigation are 1) to examine whether the MM4 can capture the primary forcing exerted by the Great Lakes on the regional climate and 2) to evaluate what model resolution and configuration are needed to simulate such forcing. Simulations over the Great Lakes region are conducted with and without representation of the lakes at four model gridpoint resolutions ranging from 15 to 90 km. One experiment at 60-km resolution is discussed in which a one-dimensional thermal eddy diffusion model is interactively coupled to the MM4 to represent the lakes. Initial and lateral boundary conditions necessary to drive these simulations are provided by European Centre for Medium-Range Weather Forecasts (ECMWF) analyses of observations. All simulations conducted are 10 days in length, from 22 December 1985 to 1 January 1986. When driven with data from ECMWF analyses of observations, the climate version of the MM4 reproduces the basic characteristics of the distribution of lake-effect precipitation over the Great Lakes Basin. Differences between simulations with and without the lakes represented indicate that the lakes accounted for approximately 25% of the precipitation over the basin during the 10-day period simulated. Over localized areas, identified as the major snowbelts downwind from the lakes, lake effects were responsible for 50%–70% of the precipitation. Basinwide precipitation did not vary greatly among the simulations with resolutions of 60, 30, and 15 km, although biases between model results and station observations did decrease slightly with increasing model resolution. Basinwide maximum and minimum temperature biases decreased more markedly with finer resolution. In the snowbelt regions downwind from the lakes, precipitation was underforecast at all four model resolutions, but precipitation generally increased with finer resolution. Differences between the results from the simulations at the three finest resolutions were greater over snowbelt regions than over the basin as a whole. A simulation was conducted with the MM4 coupled to a lake model in an interactive two-way nested configuration. The implementation of this coupling was accomplished in a straightforward manner, with no model tuning required, and added very little to the computation time needed for the MM4 system. This coupled modeling system was found to produce realistic distributions of lake surface temperatures, evaporation rates, and ice thicknesses across the lakes. In climate simulations where the MM4 is nested in a general circulation model (GCM), we believe that the use of this coupled modeling system is preferable to specifying lake parameters by interpolation from GCM output. The next step in this work is to conduct a simulation of at least one annual cycle over the region to more fully test the coupled MM4-take model system.

Great Lakes region↗
USGS2015

Evaluating unsupervised methods to size and classify suspended particles using digital in-line holography

Substantial information can be gained from digital in-line holography of marine particles, eliminating depth-of-field and focusing errors associated with standard lens-based imaging methods. However, for the technique to reach its full potential in oceanographic research, fully unsupervised (automated) methods are required for focusing, segmentation, sizing and classification of particles. These computational challenges are the subject of this paper, in which we draw upon data collected using a variety of holographic systems developed at Plymouth University, UK, from a significant range of particle types, sizes and shapes. A new method for noise reduction in reconstructed planes is found to be successful in aiding particle segmentation and sizing. The performance of an automated routine for deriving particle characteristics (and subsequent size distributions) is evaluated against equivalent size metrics obtained by a trained operative measuring grain axes on screen. The unsupervised method is found to be reliable, despite some errors resulting from over-segmentation of particles. A simple unsupervised particle classification system is developed, and is capable of successfully differentiating sand grains, bubbles and diatoms from within the surf-zone. Avoiding miscounting bubbles and biological particles as sand grains enables more accurate estimates of sand concentrations, and is especially important in deployments of particle monitoring instrumentation in aerated water. Perhaps the greatest potential for further development in the computational aspects of particle holography is in the area of unsupervised particle classification. The simple method proposed here provides a foundation upon which further development could lead to reliable identification of more complex particle populations, such as those containing phytoplankton, zooplankton, flocculated cohesive sediments and oil droplets.

Journal of Atmospheric and Oceanic Technology↗
USGS1964

Copper determinations on samples of alluvium and caliche from the rocky Range, Beaver County, Utah

A study of the distribution of copper in transported alluvium on a pediment of the Rocky Range, Beaver County, Utah, undertaken to determine whether known copper deposits in bedrock concealed by alluvium could be detected by geochemical methods, was reported in Geological Survey Research 1960 ( Erickson, R.L., and Marrenzino, A.P., 1960, Geochemical prosecting for copper in the Rocky Range, Beaver County, Utah; U.S. Geol. Survey Prof. Paper 400-B, p. B98-E101). The attached map and table supplement that paper by giving the locations at which the samples were collected and the analytical determinations of copper in the samples.

Utah↗
USGS2017

The first 50 years of the North American Breeding Bird Survey

The vision of Chandler (Chan) S. Robbins for a continental-scale omnibus survey of breeding birds led to the development of the North American Breeding Bird Survey (BBS). Chan was uniquely suited to develop the BBS. His position as a government scientist had given him experience with designing and implementing continental-scale surveys, his research background made him an effective advocate of the need for a survey to monitor pesticide effects on birds, and his prominence in the birding community gave him connections to infrastructure—a network of qualified volunteer birders who could conduct roadside surveys with standardized point counts. Having started in the eastern United States and the Atlantic provinces of Canada in 1966, the BBS now provides population change information for ∼546 species in the continental United States and Canada, and recently initiated routes in Mexico promise to greatly expand the areas and species covered by the survey. Although survey protocols have remained unchanged for 50 years, the BBS remains relevant in a changing world. Several papers that follow in this Special Section of The Condor: Ornithological Advances review how the BBS has been applied to conservation assessments, especially in combination with other large-scale survey data. A critical feature of the BBS program is an active research program into field and analytical methods to enhance the quality of the count data and to control for factors that influence detectability. Papers in the Special Section also present advances in BBS analyses that improve the utility of this expanding and sometimes controversial survey. In this Perspective, we introduce the Special Section by reviewing the history of the BBS, describing current analyses, and providing summary trend results for all species, highlighting 3 groups of conservation concern: grassland-breeding birds, aridland-breeding birds, and aerial insectivorous birds.

The Condor↗
USGS2005

The sterile-male-release technique in Great Lakes sea lamprey management

The parasitic sea lamprey (Petromyzon marinus) has been a serious pest since its introduction into the Great Lakes, where it contributed to severe imbalances in the fish communities by selectively removing large predators (Smith 1968; Christie 1974; Schneider et al.1996). Since the 1950s, restoration and maintenance of predator-prey balance has depended on the Great Lakes Fishery Commission (GLFC) sea lamprey management program. Initially, management relied primarily on stream treatments with a selective lampricide to kill larvae, on barriers to migration, and on trapping to remove potential spawners (Smith and Tibbles 1980). By the late 1970s, however, it was clear that the future of sea lamprey management lay in development of a larger array of control strategies, including more alternatives to lampricide applications (Sawyer 1980). Since then the only new alternative to chemical control to reach operational status is the release of sterilized male sea lampreys. Research on the concept began at the USGS, Hammond Bay Biological Station in Millersburg, MI (HBBS) during the 1970s (Hanson and Manion 1980). Development and evaluation continued through the 1980s, leading to the release of sterilized males in Great Lakes tributaries since 1991 (Twohey et al. 2003a). The objectives of this paper are 1) to review the implementation and evaluations of sterile-male-release technique (SMRT) as it is being applied against sea lampreys in the Great Lakes, 2) to review our current understanding of its efficacy, and 3) to identify additional research areas and topics that would increase either the efficacy of SMRT or expand its geographic potential for application.

Report↗
USGS2013

The roles of large top predators in coastal ecosystems: new insights from long term ecological research

During recent human history, human activities such as overhunting and habitat destruction have severely impacted many large top predator populations around the world. Studies from a variety of ecosystems show that loss or diminishment of top predator populations can have serious consequences for population and community dynamics and ecosystem stability. However, there are relatively few studies of the roles of large top predators in coastal ecosystems, so that we do not yet completely understand what could happen to coastal areas if large top predators are extirpated or significantly reduced in number. This lack of knowledge is surprising given that coastal areas around the globe are highly valued and densely populated by humans, and thus coastal large top predator populations frequently come into conflict with coastal human populations. This paper reviews what is known about the ecological roles of large top predators in coastal systems and presents a synthesis of recent work from three coastal eastern US Long Term Ecological Research (LTER) sites where long-term studies reveal what appear to be common themes relating to the roles of large top predators in coastal systems. We discuss three specific themes: (1) large top predators acting as mobile links between disparate habitats, (2) large top predators potentially affecting nutrient and biogeochemical dynamics through localized behaviors, and (3) individual specialization of large top predator behaviors. We also discuss how research within the LTER network has led to enhanced understanding of the ecological roles of coastal large top predators. Highlighting this work is intended to encourage further investigation of the roles of large top predators across diverse coastal aquatic habitats and to better inform researchers and ecosystem managers about the importance of large top predators for coastal ecosystem health and stability.

Florida;Georgia;Massachusetts↗
USGS2002

Prey of the Peregrine Falcon (Falco peregrinus cassini) in Southern Argentina and Chile

The Peregrine Falcon (Falco peregrinus cassini) in Patagonia attracted wide interest two decades ago when there was a focus on determining the taxonomic position of the Pallid Falcon (also called Kleinschmidt's falcon and Tierra del Fuego falcon; formerly named Falco kreyenborgi). In 1981, however, the pallid falcon was confirmed to be a pale color morph of the peregrine, and since that time, little work has been conducted on this color morph. Continent-wide research has continued and has yielded a fair understanding of the breeding distribution of the Peregrine Falcon in South America. Also, two preliminary food habits studies on the peregrine have been completed in Patagonia. Together those papers provided a list of 23 species observed as prey, and McNutt listed another eight species seen pursued (but not captured) by peregrines. The purpose of this paper is to assemble all that has been published on peregrine food habits for Patagonia and Tierra del Fuego and to add to that list from our 1980 and 1981 expeditions.

Journal of Raptor Research↗