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As part of a program undertaken cooperatively by the Liberian Geological Survey (LGS) and the U. S. Geological Survey (USGS), under the sponsorship of the Government of Liberia and the Agency for International Development, U. S. Department of State, Liberia was mapped by geologic and geophysical methods during the period 1965 to 1972.
As part of a program undertaken cooperatively by the Liberian Geological Survey (LGS) and the U. S. Geological Survey (USGS), under the sponsorship of the Government of Liberia and the Agency for International Development, U. S. Department of State, Liberia was mapped by geologic and geophysical methods during the period 1965 to 1972. The resulting geologic and geophysical maps are published in ten folios, each covering one quadrangle (see index map). The Juazohn quadrangle was systematically mapped by the author from December 1970 to June 1972. Field data provided by private companies and other members of the LGS-USGS project were used in map compilation, and are hereby acknowledged.
As part of a program undertaken cooperatively by the Liberian Geological Survey (LGS) and the U. S. Geological Survey (USGS), under the sponsorship of the Government of Liberia and the Agency for International Development, U. S. Department of State, Liberia was mapped by geologic and geophysical methods during the period 1965 to 1972. The resulting geologic and geophysical maps are published in ten folios, each covering one quadrangle (see index map). The first systematic mapping in the Harper quadrangle was by Baker, S. P. Srivastava, and W. E. Stewart (LGS) at a scale of 1:500,000 in the vicinity of Harper in the southeastern, and of Karloke in the northeastern part of the quadrangle in 1960-61. Brock and Chidester carried out systematic mapping of the quadrangle at a scale of 1:250,000 in the period September 1971-May 1972; the geologic map was compiled from field data gathered by project geologists and private companies as indicated in the source diagram, photogeologic maps, interpretation of airborne magnetic and radiometric surveys, field mapping, and ground-based radiometric surveys in which hand-held scintillators were used. R. W. Bromery, C. S. Wotorson, and J. C. Behrendt contributed to the interpretation of geophysical data. Total-intensity aeromagnetic and total-count gamma radiation maps (Behrendt and Wotorson, in press a, b), and unpublished data derived from those maps, including the near-surface and the regional magnetic components and aeromagnetic/radiometric correlations, were used in the interpretation.
The United States Geological Survey (USGS) National Strong Motion Project (NSMP) has the primary U.S. government responsibility to acquire, process, and disseminate significant strong-motion earthquake ground motion records measured at surficial free-field stations, structures (buildings, dams, and bridges, and geotechnical arrays to the earthquake engineering community. As a result of the deployment of modern seismic instrumentation and growth of tools such as web-services, earthquake data from U.S. and international seismic networks are more accessible than ever. Our mission is to provide raw and processed strong-motion waveforms with PGA values greater than 0.1%g for M3.0 earthquakes and larger in California and M4.0 and larger within the conterminous US, Hawaii, Puerto Rico, and Alaska. Datasets of interest to the engineering and geophysics communities, such as event sequences in areas of induced seismicity and significant global events, are also processed and posted at the Center for Engineering Strong Motion Data (CESMD) at strongmotioncenter.org when available through collaboration with the international strong-motion data community. Here we outline (1) the NSMP’s current workflow to acquire, process, and distribute data at CESMD; (2) our new endeavours and collaborations focusing on comparison and integration of waveform processing software, development of techniques for metadata quality checks before and after earthquakes, and construction of a dynamic site characterization repository; and (3) our topics for possible collaboration topics across the global strong-motion community.
The Dengate quadrangle is an area of approximately 51 square miles in western Morton County, southwestern North Dakota. The quadrangle is about 40 miles west of Bismarck, the State capitol (fig. 1) and about 3.5 miles east of Glen Ullin (population 1,087). Interstate Highway 94,U.S. Highway 10, and the Northern Pacific Railroad cross the northern part of the area in an east-west direction. The Dengate quadrangle is one of a group of 14 adjoining 71/2-minute quadrangles (fig. 1) that are being mapped by the U.S. Geological Survey to furnish a basis for classification of lands withdrawn by the Federal Government pending classification for coal, and to contribute to the geologic map atlas of the United States. Most of the fieldwork for the Dengate quadrangle was done during the late summers and early autumns of 1965 and 1966. During the summer of 1966, the U.S. Geological Survey conducted a drilling program in the Dengate and nearby quadrangles (Smith, 1970) to gather information on the existence, thickness, and depth of lignite beds in withdrawn Federal lands. Two of the holes drilled are in the Dengate quadrangle.
This geologic map is the result of a cooperative effort of the U.S. Geological Survey, the National Park Service, the U.S. Forest Service, and the Bureau of Land Management (BLM) and the Kaibab-Paiute Tribe to provide a regional geologic database for resource management officials of all government and agencies, city municipalities, private enterprises, and individuals of this part of the Arizona Strip. The Arizona Strip is part of northwestern Arizona north of the Colorado River and bounded by the States of Nevada and Utah. Field work on the Kaibab-Paiute Indian Reservation was conducted from 2002 to 2005 with permission from the Kaibab-Paiute Tribal Government of that administration and permission was granted to publish a geologic map of 4 quadrangles online (Billingsley and others, 2004). The Kaibab-Paiute Tribal government of 2006 to 2008 requested that all geologic information within the Kaibab-Paiute Indian Reservation not be published as part of the Fredonia 30' x 60' quadrangle (this publication). For further information, contact the Kaibab-Paiute Tribal government at HC 65 Box 2, Fredonia, Arizona, 86022, telephone # (928) 643-7245. Visitors to the Kaibab-Paiute Indian Reservation are required to obtain a permit and permission for access from the Tribal Offices at the junction of State Highway 389 and the paved road leading to Pipe Spring National Monument. The Fredonia 30' x 60' quadrangle encompasses approximately 5,018 km2 (1,960 mi2) within Mohave and Coconino Counties, northern Arizona and is bounded by longitude 112 deg to 113 deg W., and latitude 36 deg 30' to 37 deg N. The map area lies within the southern Colorado Plateaus geologic province (herein Colorado Plateau). The map area is locally subdivided into seven physiographic parts: the Grand Canyon (Kanab Canyon and its tributaries), Kanab Plateau, Uinkaret Plateau, Kaibab Plateau, Paria Plateau, House Rock Valley, and Moccasin Mountains as defined by Billingsley and others, 1997, (fig. 1). Elevations range from 2,737 m (8,980 ft) just west of State Highway 67 on the Kaibab Plateau, southeast corner of the map area to about 927 m (3,040 ft) in Kanab Canyon, south-central edge of the map area.
Minnesota wolves ( Canis sp.) sometimes are reported to have affinity to a small, narrow-skulled eastern form ( Canis lupus lycaon Schreber, 1775) and sometimes to a larger, broader western form ( Canis lupus nubilus Say, 1823). We found that pre-1950 Minnesota wolf skulls were similar in size to those of wolves from southeastern Ontario and smaller than those of western wolves. However, Minnesota wolf skulls during 1970–1976 showed a shift to the larger, western form. Although Minnesota skull measurements after 1976 were unavailable, rostral ratios from 1969 through 1999 were consistent with hybridization between the smaller eastern wolf and the western form. Our findings help resolve the different taxonomic interpretations of Minnesota skull morphology and are consistent with molecular evidence of recent hybridization or intergradation of the two forms of wolves in Minnesota. Together these data indicate that eastern- and western-type wolves historically mixed and hybridized in Minnesota and continue to do so. Our findings are relevant to a recent government proposal to delist wolves from the endangered species list in Minnesota and surrounding states.
Introduction The U.S. Geological Survey (USGS)—a Federal civilian agency—and U.S. military and intelligence agencies collaborate on mapping and remote sensing and have since the establishment of the USGS. The organizations exchange data and information and share technology to further their respective missions in service to the American people. Often referred to as examples of “good government” or “whole of government,” the collaboration avoids costly duplication and maximizes time and effort for the government sectors. Collaboration between these sectors started with the original mapping of the United States and evolved to include remote sensing after the advent of aerial photography and satellite imagery.
On May 29, 2006, mud and gases began erupting unexpectedly from a vent 150 meters away from a hydrocarbon exploration well near Sidoarjo, East Java, Indonesia. The eruption, called the LUSI (Lumpur 'mud'-Sidoarjo) mud volcano, has continued since then at rates as high as 160,000 m3 per day. At the request of the United States Department of State, the U.S. Geological Survey (USGS) has been providing technical assistance to the Indonesian Government on the geological and geochemical aspects of the mud eruption. This report presents initial characterization results of a sample of the mud collected on September 22, 2007, as well as inerpretive findings based on the analytical results. The focus is on characteristics of the mud sample (including the solid and water components of the mud) that may be of potential environmental or human health concern. Characteristics that provide insights into the possible origins of the mud and its contained solids and waters have also been evaluated.
The use of light-emitting diodes (LEDs) is expanding because of environmental issues and the efficiency and cost savings achieved compared with use of traditional incandescent lighting. The longer life and reduced power consumption of some LEDs have led to annual energy savings, reduced maintenance costs, and lower emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides from powerplants because of the resulting decrease in energy consumption required for lighting applications when LEDs are used to replace less-energy-efficient sources. Metals such as arsenic, gallium, indium, and the rare-earth elements (REEs) cerium, europium, gadolinium, lanthanum, terbium, and yttrium are important mineral materials used in LED semiconductor technology. Most of the world's supply of these materials is produced as byproducts from the production of aluminum, copper, lead, and zinc. Most of the rare earths required for LED production in 2011 came from China, and most LED production facilities were located in Asia. The LED manufacturing process is complex and is undergoing much change with the growth of the industry and the changes in demand patterns of associated commodities. In many respects, the continued growth of the LED industry, particularly in the general lighting sector, is tied to its ability to increase LED efficiency and color uniformity while decreasing the costs of producing, purchasing, and operating LEDs. Research is supported by governments of China, the European Union, Japan, the Republic of Korea, and the United States. Because of the volume of ongoing research in this sector, it is likely that the material requirements of future LEDs may be quite different than LEDs currently (2011) in use as industry attempts to cut costs by reducing material requirements of expensive heavy rare-earth phosphors and increasing the sizes of wafers for economies of scale. Improved LED performance will allow customers to reduce the number of LEDs in automotive, electronic, and lighting applications, which could reduce the overall demand for material components. Non-Chinese sources for rare earths are being developed, and some of these new sources are likely to be operational in time to meet increasing demand for rare earths from the LED sector. Because most LED component production and manufacturing occurs in Asia and many LED producers have established supply contracts with Chinese producers of rare earths, a significant amount of the metallic gallium, indium, and the rare earths used for LED production will likely continue to come from Chinese sources at least for the next 5 years; however, a greater amount of these materials are now being processed in Japan, the Republic of Korea, and Taiwan. As non-Chinese sources of rare earths come into production, these new mines are likely to be sources of light REEs, but China will likely remain the leading source of supply for the heavy REEs suitable for use as LED dopants and phosphors at least for the next few years. Increased research in the development of phosphors that use smaller amounts of or different REEs is intended to reduce dependence on rare earths from China. Supply disruption of rare earths and other specialty metals could take place if China's specialty metal exports are redirected to domestic markets. The cost of recovery is high and the lifespan for LEDs is comparatively long; thus, the LED waste volume was low in 2010, and few LEDs were recycled. The minute metal content of LEDs leads to a high cost for recovery, so recycling of LEDs outside of electronic waste is unlikely in the near term, although some LED producers are evaluating recycling options. Recycling of metals from LEDs in electronic waste is possible if the costs of recovering metals are justified by demand and metal prices.
Accurate estimates of flood frequency and magnitude are a key component of any effective nationwide flood risk management and flood damage abatement program. In addition to accuracy, methods for estimating flood risk must be uniformly and consistently applied because management of the Nation’s water and related land resources is a collaborative effort involving multiple actors including most levels of government and the private sector. Flood frequency guidelines have been published in the United States since 1967, and have undergone periodic revisions. In 1967, the U.S. Water Resources Council presented a coherent approach to flood frequency with Bulletin 15, “A Uniform Technique for Determining Flood Flow Frequencies.” The method it recommended involved fitting the log-Pearson Type III distribution to annual peak flow data by the method of moments. The first extension and update of Bulletin 15 was published in 1976 as Bulletin 17, “Guidelines for Determining Flood Flow Frequency” (Guidelines). It extended the Bulletin 15 procedures by introducing methods for dealing with outliers, historical flood information, and regional skew. Bulletin 17A was published the following year to clarify the computation of weighted skew. The next revision of the Bulletin, the Bulletin 17B, provided a host of improvements and new techniques designed to address situations that often arise in practice, including better methods for estimating and using regional skew, weighting station and regional skew, detection of outliers, and use of the conditional probability adjustment. The current version of these Guidelines are presented in this document, denoted Bulletin 17C. It incorporates changes motivated by four of the items listed as “Future Work” in Bulletin 17B and 30 years of post-17B research on flood processes and statistical methods. The updates include: adoption of a generalized representation of flood data that allows for interval and censored data types; a new method, called the Expected Moments Algorithm, which extends the method of moments so that it can accommodate interval data; a generalized approach to identification of low outliers in flood data; and an improved method for computing confidence intervals. Federal agencies are requested to use these Guidelines in all planning activities involving water and related land resources. State, local, and private organizations are encouraged to use these Guidelines to assure uniformity in the flood frequency estimates that all agencies concerned with flood risk should use for Federal planning decisions. This revision is adopted with the knowledge and understanding that review of these procedures will be ongoing. Updated methods will be adopted when warranted by experience and by examination and testing of new techniques.
The U. S. Geological Survey's (USGS) Commercial Remote Sensing Data Contracts (CRSDCs) provide government agencies with access to a broad range of commercially available remotely sensed airborne and satellite data. These contracts were established to support The National Map partners, other Federal Civilian agency programs, and Department of Defense programs that require data for the United States and its territories. Experience shows that centralized procurement of remotely sensed data leads to considerable cost savings to the Federal government through volume discounts, reduction of redundant contract administrative costs, and avoidance of duplicate purchases. These contracts directly support the President's Commercial Remote Sensing Space Policy, signed in 2003, by providing a centralized mechanism for civil agencies to acquire commercial remote sensing products to support their mission needs in an efficient and coordinated way. CRSDC administration is provided by the USGS Mid-Continent Mapping Center in Rolla, Missouri.
With 75 historically active volcanoes, Indonesia is the world’s most volcanically active nation. Its volcanoes are legendary throughout the world, with the notorious 19th-century eruptions at Mount Tambora (1815) and Krakatau (1883), and the eruption that created the giant Toba Caldera in Sumatra (75,000 years ago)—the Earth’s largest volcanic eruption in the past 100,000 years. Just in the past 20 years, more than 36 volcanoes have erupted, some multiple times, threatening millions of people. The Government of Indonesia responds to this daunting volcanic threat from Indonesia’s Center for Volcanology and Geologic Hazards Mitigation (CVGHM) offices in Bandung. From there, dozens of staff members coordinate operations at 77 small observatories spread out across the 5,000-kilometer-long archipelago that is Indonesia. For more than 50 years, the United States has worked in partnership with the Government of Indonesia to reduce the risk of volcanic eruptions and to save lives. Today, the two governments cooperate through an agreement between CVGHM and the U.S. Geological Survey’s Volcano Disaster Assistance Program (VDAP). Each year CVGHM and VDAP representatives convene to discuss priorities for the upcoming 12 months. They outline a series of training efforts, field campaigns, equipment deployments, and timely topics that require further exploration and development.
Habitat loss, agricultural intensification, pesticide use, disease and climate change have contributed to the decline of numerous insect groups. Recent government initiatives have recognized the importance of supplementary wildflower plantings to support native bee populations, yet little information exists on the attractiveness of recommended plant species to bees. With the use of network analysis and generalized linear mixed models, we evaluated the attractiveness of 18 wildflower species belonging to 6 families (Apiaceae, Apocynaceae, Asteraceae, Fabaceae, Lamiaceae and Verbenaceae) planted in a randomized block design by conducting timed targeted sweep netting surveys. We also evaluated the floral preferences of four bee species ( Apis mellifera , Halictus poeyi/ligatus , Bombus griseocollis and Bombus impatiens ) to the planted wildflower species with the use of GLMs. We found that Asclepias tuberosa, Gaillardia pulchella and Verbena hastata attracted the greatest abundance, richness and diversity of native bees compared to the other wildflower species. Collectively, Asclepias tuberosa, Gaillardia pulchella and Verbena hastata attracted 89% of all bee taxa in the study, which exemplifies the importance of including them in a wildflower mixture to attract native bees. While several wildflower species attracted low abundance, richness and diversity of native bees such as Monarda fistulosa, Symphyotrichum pilosum and Eryngium yuccifolium , they are still ecologically important for attracting uncommon or specialist bee species and should be included in seed mixes for this reason. Solution . Our results highlight that each species of native wildflower varies in the abundance, richness and diversity of native bees they attract; this could be considered in the decision-making of landowners and land managers to promote wildflower plantings to reflect the needs of certain groups of bees of conservation interest.
Declines among species of insect pollinators, especially butterflies, has garnered attention from scientists and managers. Often these declines have spurred governments to declare some species as threatened or endangered. We used existing presence–absence data from surveys for the threatened Dakota skipper Hesperia dacotae (Skinner) to build statistical maps of species presence that could be used to inform future monitoring designs. We developed a hierarchical Bayesian modeling approach to estimate the spatial distribution and temporal trend in Dakota skipper probability of presence. Our model included a spatial random effect and fixed effects for the proportion of two grassland habitat types: those on well-drained soils and those on poorly drained soils; as well as the topographic slope. The results from this model were then used to assess sampling strategies with two different monitoring objectives: locating new Dakota skipper colonies or monitoring the proportion of historically (pre-2000) extant colonies. Our modeling results suggested that the distribution of Dakota skippers followed the distribution of remnant grasslands and that probabilities of presence tended to be higher in topographically diverse grasslands with well-drained soils. Our analysis also showed that the probability of presence declined throughout the northern Great Plains range. Our simulations of the different sampling designs suggested that new detections were expected when sampling where Dakota skippers likely occurred historically, but this may lead to a tradeoff with monitoring existing sites. Prior information about the extant sites may help to ameliorate this tradeoff.
Simulation of induced movement of air in the unsaturated zone provides a method to determine permeability and to design vapor extraction remediation systems. A previously published solution to the airflow equation for the case in which the unsaturated zone is separated from the atmosphere by a layer of lower permeability (such as a clay layer) has been superseded. The new solution simulates airflow through the layer of lower permeability more rigorously by defining the leakage in terms of the upper boundary condition rather than by adding a leakage term to the governing airflow equation. This note presents the derivation of the new solution. Formulas for steady state pressure, specific discharge, and mass flow in the domain are obtained for the new model and for the case in which the unsaturated zone is in direct contact with the atmosphere.
Background. Soils and sediments in certain mining regions of Brazil contain an unusually large amount of arsenic (As), which raises concerns that mining could promote increased As mobility, and thereby increase the risks of contaminating water supplies. Objectives. The purpose of t his study was to identify the most important factors governing As mobility in sediments and soils near three gold-mining sites in the State of Minas Gerais, Brazil. Methods. Surface and sub-surface soil samples were collected at those sites and characterized by chemical and mineralogical analyses. Oxalate (Feo) and citrate-bicarbonate-dithionite (Fed) iron contents were determined by atomic absorption spectroscopy (AAS). Arsenic mobilization was measured after incubating the samples in a 2.5 mM CaCl2 solution under anaerobic conditions for 1, 28, 56, 84, or 112 days. The solution concentrations of As, Fe, and Mn were then measured by inductively coupled plasma-mass spectrometry (ICP-MS) and AAS, respectively. Results and Discussion. Results indicated that As mobilization is largely independent of both the total As and the Feo/Fed ratio of the solid phase. Soluble As is roughly controlled by the Fe (hydr)oxide content of the soil, but a closer examination of the data revealed the importance of other highly weathered clay minerals and organic matter. Large amounts of organic matter and a low iron oxide content should favor As leaching from soils and sediments. Under reducing conditions, As is mobilized by the reductive dissolution of Fe and/or Mn oxides. However, released As may be readsorbed depending on the sorptive properties of the soil. Gibbsite is particularly effective in adsorbing or readsorbing As, as is the remaining unreduced fraction of the iron (hydr)oxides. Conclusion and Outlook. In general, low soluble As is rel ated to the presence of gibbsite, a large amount of iron oxides, and a lack of organic matter in the solid phase. This has environmental significance because gibbsite is thermodynamically more stable than Fe oxides under anaerobic conditions, such as those found in waterlogged soils and lake sediments. ?? 2006 ecomed publishers (Verlagsgruppe Hu??thig Jehle Rehm GmbH), D-86899 Landsberg and Tokyo.
Introduction The U.S. Geological Survey (USGS) is an impartial scientific organization that strives to produce scientific results that are relevant to the people of the United States and their land and resource managers. In cooperation with American Indian and Alaska Native governments, the USGS conducts research on water and mineral resources, animals and plants of environmental, economic, or subsistence importance, natural hazards, and geologic resources. Digital data on cartography, mineral resources, stream flows, biota, and other data sets are available to American Indian and Alaska Native institutions. The USGS recognizes the need learn from and to share knowledge with Native peoples. This report describes most of the activities that the USGS conducted with American Indian and Alaska Native governments, educational institutions, and individuals during Federal fiscal year 1998.