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At least 1,405 records · Page 78Linked to original sources
USGS2022

Ground failure triggered by the 7 January 2020 M6.4 Puerto Rico earthquake

The 7 January 2020 M 6.4 Puerto Rico earthquake, the mainshock of an extended earthquake sequence, triggered significant ground failure. In this study, we detail the ground failure that occurred based largely on a postearthquake field reconnaissance campaign that we conducted. We documented more than 300 landslides, mainly rock falls that were concentrated in areas where peak ground acceleration (PGA) exceeded 30% g ; sparse smaller landslides occurred in highly susceptible areas more than 50 km from the epicenter and at PGA values <10% g . Though some of the largest mass movements were in natural slopes, rock falls in road cuts had more impact because they caused widespread transportation disruption. Some structures also were damaged by landslides, but no landslide‐related fatalities were reported. Liquefaction and related lateral spreading were severe in some areas, causing damage to residential and commercial structures and a power plant. Most of the liquefaction occurred in coastal areas where shaking exceeded 50% g , though some of the most damaging instances were in Ponce, where shaking estimates were as low as 20% g . In this article, we summarize the most notable ground failures and detail the overall patterns that we observed. The observations and compiled inventory datasets presented here are valuable because no island‐wide hazard maps for earthquake‐triggered landslides or liquefaction have been developed for Puerto Rico, and postevent inventories are vital for such an effort. In general, the datasets presented here contribute to a global understanding of coseismic ground‐failure hazard by presenting detailed observations for a relatively moderate ground‐failure event with well‐constrained shaking estimates; current models and expectations are biased by the tendency to collect detailed datasets mainly for exceptional events.

Puerto Rico↗
USGS1903

Chemical analyses of igneous rocks published from 1884 to 1900, with a critical discussion of the character and use of analyses

In the first two or three decades of the last century, when the study of rocks as such was being differentiated from that of minerals and of rock terranes that is, when the science of petrogaphy was in its infancy little attention was paid to their chemical features. It is true that a number had been analyzed, but these were for the most part rocks that were of such a character as to lead the investigator of those early days to consider them as minerals, as was the case with the first described Ihcrzolite and wehrlite. In contradistinction to the individually well-defined minerals, rocks were regarded as merely aggregates of minerals, in presumably fortuitous combinations, and lacking that definiteness or constancy of composition in one mass or in different masses which would justify their chemical study as a whole. As, however, they became more and more the subjects of special research, beginning with the earliest investigations of Cordiera, a knowledge of their chemical composition assumed gradually increasing interest. The great importance of this side of the study of rocks was first clearly recognized by Abich, who pointed out, as early as 1841, the, necessity of a knowledge of their chemical composition for the solution of such problems as their origin, mode of formation, and connection with the interior of the earth, as well as the value of a comparison of their analyses as a proper basis for their classification and nomenclature. To him, therefore, is due the credit, of introducing the chemical composition of rocks as a basis for their classification; though the good influence of this suggestion for their right understanding was largely nullified by the coincident use of the feldspars alone as one of the main factors of classification, an idea which has had a deplorably retarding influence on the development of systematic petrography for many years, and which, even at the present day, holds many systematists firmly in its grasp.

Professional Paper↗
USGS2000

Estimating the impacts of oil spills on polar bears

The polar bear is the apical predator and universal symbol of the Arctic. They occur throughout the Arctic marine environment wherever sea ice is prevalent. In the southern Beaufort Sea, polar bears are most common within the area of the outer continental shelf, where the hunt for seals along persistent leads and openings in the ice. Polar bears are a significant cultural and subsistence component of the lifestyles of indigenous people. They may also be one of the most important indicators of the health of the Arctic marine environment. Polar bears have a late age of maturation, a long inter0brth period, and small liter sizes. These life history features make polar bear populations susceptible to natural and human perturbations. Petroleum exploration and extraction have been in progress along the coast of northern Alaska for more than 25 years. Until recently, most activity has taken place on the mainland or at sites connected to the shore by a causeway. In 1999, BP Exploration-Alaska began constructing the first artificial production island designed to transport oil through sub-seafloor pipelines. Other similar projects have been proposed to begin in the next several years. The proximity of oil exploration and development to principal polar bear habitats raises concerns, and with the advent of true off-shore development projects, these concerns are compounded. Contact with oil and other industrial chemicals by polar bears, through grooming, consumption of tainted food, or direct consumption of chemicals, may be lethal. The active ice where polar bears hunt is also where spilled oil may be expected to concentrate during spring break-up and autumn freeze-up. Because of this, we could expect that an oil spill in the waters and ice of the continental shelf would have profound effects on polar bears. Assessments of the effects of spills, however, have not been done. This report described a promising method for estimating the effects of oil spills on polar bears in the Arctic marine environment. It uses enough real data to illuminate necessary calculations and illustrate the value of the methods. The results and conclusions presented here are only examples of possible scenarios resulting from a new estimation method. Final assessment of the potential impacts to polar bears of an oil spill remains a work in progress.

Alaska, Northwest Territories, Yukon↗
USGS2020

Using the Delphi process to gather information from a Bald Eagle expert panel

Bald eagle ( Haliaeetus leucocephalus ) populations are classified by the Southwest Alaska Network (SWAN) of the National Park Service as a vital sign of biological integrity, largely because of their importance as an indicator species for environmental contaminants and human disturbance. Though Bald Eagles are plentiful in Alaska, it is still imperative to have a monitoring plan that allows for the estimation of population sizes and detection of significant changes in populations. Currently, Bald Eagles are monitored in Kenai Fjords National Park, Katmai National Park and Preserve, Lake Clark National Park and Preserve, and Wrangell – St. Elias National Park, but each park uses different monitoring procedures and evaluation criteria. This makes it difficult for scientists and managers to compare data, detect changes in overall populations, and make effective management decisions. Our research is using a formal structured decision-making process to ensure that the Bald Eagle monitoring conducted by the parks is standardized and meets programmatic goals and objectives. We implemented a Delphi process, which is an iterative survey technique that is used to gather expert opinion. We used online questionnaires to gather information and opinions from National Park Service scientists and managers, eagle experts, and other interested parties. We identified important stressors and feasible monitoring metrics, which were tied to the means objectives for the Bald Eagle monitoring program: minimize cost, minimize effort, maximize ability to detect change in populations, and maximize accurate information about Bald Eagles. We will also analyze monitoring metrics using a consequence table, which determines the performance of each objective in terms of the means objectives chosen by expert panelists. This information will help to create a more accurate conceptual model of the system to guide development of a Bald Eagle monitoring program that can be standardized among Southwest Alaska National Parks.

Alaska↗
USGS2012

An online database for IHN virus in Pacific Salmonid fish: MEAP-IHNV

The MEAP-IHNV database provides access to detailed data for anyone interested in IHNV molecular epidemiology, such as fish health professionals, fish culture facility managers, and academic researchers. The flexible search capabilities enable the user to generate various output formats, including tables and maps, which should assist users in developing and testing hypotheses about how IHNV moves across landscapes and changes over time. The MEAP-IHNV database is available online at http://gis.nacse.org/ihnv/ (fig. 1). The database contains records that provide background information and genetic sequencing data for more than 1,000 individual field isolates of the fish virus Infectious hematopoietic necrosis virus (IHNV), and is updated approximately annually. It focuses on IHNV isolates collected throughout western North America from 1966 to the present. The database also includes a small number of IHNV isolates from Eastern Russia. By engaging the expertise of the broader community of colleagues interested in IHNV, our goal is to enhance the overall understanding of IHNV epidemiology, including defining sources of disease outbreaks and viral emergence events, identifying virus traffic patterns and potential reservoirs, and understanding how human management of salmonid fish culture affects disease. Ultimately, this knowledge can be used to develop new strategies to reduce the effect of IHN disease in cultured and wild fish.

Fact Sheet↗
USGS2015

Surrogate Analysis and Index Developer (SAID) tool

The use of acoustic and other parameters as surrogates for suspended-sediment concentrations (SSC) in rivers has been successful in multiple applications across the Nation. Tools to process and evaluate the data are critical to advancing the operational use of surrogates along with the subsequent development of regression models from which real-time sediment concentrations can be made available to the public. Recent developments in both areas are having an immediate impact on surrogate research and on surrogate monitoring sites currently (2015) in operation. The Surrogate Analysis and Index Developer (SAID) standalone tool, under development by the U.S. Geological Survey (USGS), assists in the creation of linear regression models that relate constituent and surrogate parameters by providing visual and quantitative diagnostics to the user. SAID also processes acoustic parameters to be used as explanatory variables for SSC. The sediment acoustic method utilizes acoustic parameters from fixed-mount stationary equipment. The theory and method used by the SAID tool have been described in recent publications. The tool also serves to support sediment-acoustic-index methods and other surrogate guidelines such as turbidity and SSC (Rasmussen and others, 2009). The regression models created in SAID can be used in utilities that have been developed to work with the USGS National Water Information System (NWIS) and for the USGS National Real-Time Water Quality (NRTWQ) Web site. The real-time dissemination of predicted SSC and prediction intervals for each time step has substantial potential to improve understanding of sediment-related water quality and associated engineering and ecological management decisions.

Open-File Report↗
USGS2019

Differential effects of temperature and salinity on growth and mortality of oysters (Crassostrea virginica) in Barataria Bay and Breton Sound, Louisiana

Temperature and salinity and their interaction exert a major control on the life cycle of the eastern oyster (Crassostrea virginica), affecting reproduction, development, growth, and mortality. Quantifying specific temperature and salinity relationships on oyster growth and mortality has however proven difficult, with data suggesting potentially region-specific responses. Legacy and recent data from field tray studies from public oyster grounds in Barataria Bay and Breton Sound were used to estimate growth and mortality rates as a function of temperature and salinity. Previous studies conducted in Barataria Bay and Breton Sound reported differences in growth and mortality between the basins. In the present study, environmental conditions were synchronized to compare growth and mortality between basins at similar combinations of temperature and salinity. Results indicate that when temperature and salinity are the same (synchronized), seasonal oyster growth and mortality rates still differ between Barataria Bay and Breton Sound. Given the same salinity and temperature conditions, differences in growth and mortality rates between estuaries may persist due to differences in other environmental conditions (i.e., food quality and composition, hydrology, site history, salinity variation) or localized genetic adaptations to environmental conditions.

Lousianna↗
USGS1996

Inductively coupled plasma-mass spectrometric method for the determination of dissolved trace elements in natural water

An inductively coupled plasma-mass spectrometry method was developed for the determination of dissolved Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sr, Tl, U, V, and Zn in natural waters. Detection limits are generally in the 50-100 picogram per milliliter (pg/mL) range, with the exception of As which is in the 1 microgram per liter (ug/L) range. Interferences associated with spectral overlap from concomitant isotopes or molecular ions and sample matrix composition have been identified. Procedures for interference correction and reduction related to isotope selection, instrumental operating conditions, and mathematical data processing techniques are described. Internal standards are used to minimize instrumental drift. The average analytical precision attainable for 5 times the detection limit is about 16 percent. The accuracy of the method was tested using a series of U.S. Geological Survey Standard Reference Water Standards (SWRS), National Research Council Canada Riverine Water Standard, and National Institute of Standards and Technology (NIST) Trace Elements in Water Standards. Average accuracies range from 90 to 110 percent of the published mean values.

Open-File Report↗
USGS2008

Towards monitoring land-cover and land-use changes at a global scale: the global land survey 2005

Land cover is a critical component of the Earth system, infl uencing land-atmosphere interactions, greenhouse gas fl uxes, ecosystem health, and availability of food, fi ber, and energy for human populations. The recent Integrated Global Observations of Land (IGOL) report calls for the generation of maps documenting global land cover at resolutions between 10m and 30m at least every fi ve years (Townshend et al., in press). Moreover, despite 35 years of Landsat observations, there has not been a unifi ed global analysis of land-cover trends nor has there been a global assessment of land-cover change at Landsat-like resolution. Since the 1990s, the National Aeronautics and Space Administration (NASA) and the U.S. Geological Survey (USGS) have supported development of data sets based on global Landsat observations (Tucker et al., 2004). These land survey data sets, usually referred to as GeoCover &trade;, provide global, orthorectifi ed, typically cloud-free Landsat imagery centered on the years 1975, 1990, and 2000, with a preference for leaf-on conditions. Collectively, these data sets provided a consistent set of observations to assess land-cover changes at a decadal scale. These data are freely available via the Internet from the USGS Center for Earth Resources Observation and Science (EROS) (see http://earthexplorer.usgs.gov or http://glovis.usgs.gov). This has resulted in unprecedented downloads of data, which are widely used in scientifi c studies of land-cover change (e.g., Boone et al., 2007; Harris et al., 2005; Hilbert, 2006; Huang et al. 2007; Jantz et al., 2005, Kim et al., 2007; Leimgruber, 2005; Masek et al., 2006). NASA and USGS are continuing to support land-cover change research through the development of GLS2005 - an additional global Landsat assessment circa 20051 . Going beyond the earlier initiatives, this data set will establish a baseline for monitoring changes on a 5-year interval and will pave the way toward continuous global land-cover monitoring at Landsat-like resolution in the next decade.

Photogrammetric Engineering and Remote Sensing↗
USGS2014

Hydrostratigraphic interpretation of test-hole and borehole geophysical data, Kimball, Cheyenne, and Deuel Counties, Nebraska, 2011-12

Recently (2004) adopted legislation in Nebraska requires a sustainable balance between long-term supplies and uses of surface-water and groundwater and requires Natural Resources Districts to understand the effect of groundwater use on surface-water systems when developing a groundwater-management plan. The South Platte Natural Resources District (SPNRD) is located in the southern Nebraska Panhandle and overlies the nationally important High Plains aquifer. Declines in water levels have been documented, and more stringent regulations have been enacted to ensure the supply of ground-water will be sufficient to meet the needs of future generations. Because an improved understanding of the hydrogeologic characteristics of this aquifer system is needed to ensure sustainability of groundwater withdrawals, the U.S. Geological Survey, in cooperation with the SPNRD, Conservation and Survey Division of the University of Nebraska-Lincoln, and the Nebraska Environmental Trust, began a hydrogeologic study of the SPNRD to describe the lithology and thickness of the High Plains aquifer. This report documents these characteristics at 29 new test holes, 28 of which were drilled to the base of the High Plains aquifer. Herein the High Plains aquifer is considered to include all hydrologically connected units of Tertiary and Quaternary age. The depth to the base of aquifer was interpreted to range from 37 to 610 feet in 28 of the 29 test holes. At some locations, particularly northern Kimball County, the base-of-aquifer surface was difficult to interpret from drill cutting samples and borehole geophysical logs. The depth to the base of aquifer determined for test holes drilled for this report was compared with the base-of-aquifer surface interpreted by previous researchers. In general, there were greater differences between the base-of-aquifer elevation reported herein and those in previous studies for areas north of Lodgepole Creek compared to areas south of Lodgepole Creek. The largest difference was at test hole 5-SP-11, where an Ogallala-filled paleovalley prevously had been interpreted based on relatively sparse test-hole data west of 5-SP-11. The base of aquifer near test hole 5-SP-11 reported herein is approximately 230 ft higher in elevation than previously interpreted. Among other test holes that are likely to have been drilled in Ogallala-filled paleovalleys, the greatest difference in the interpreted base of aquifer was for test hole 7-CC-11, northeast of Potter, Nebraska, where the base of aquifer is 180 feet deeper than previously interpreted. Interpretation of test-hole and borehole geophysical data for 29 additional test holes will improve resource managers’ understanding of the hydrogeologic characteristics, including aquifer thickness. Aquifer thickness, which is related to total water in storage, is not well quantified in the north and south tablelands. The additional hydrostratigraphic interpretations provided in this report will improve the hydrogeologic framework used in current (2014) and future groundwater models, which are the basis for many water-management decisions.

Nebraska↗
USGS2022

Predicting flood damage probability across the conterminous United States

Floods are the leading cause of natural disaster damages in the United States, with billions of dollars incurred every year in the form of government payouts, property damages, and agricultural losses. The Federal Emergency Management Agency oversees the delineation of floodplains to mitigate damages, but disparities exist between locations designated as high risk and where flood damages occur due to land use and climate changes and incomplete floodplain mapping. We harnessed publicly available geospatial datasets and random forest algorithms to analyze the spatial distribution and underlying drivers of flood damage probability caused by excessive rainfall and overflowing water bodies across the conterminous United States. From this, we produced the first spatially complete map of flood damage probability for the nation, along with spatially explicit standard errors for four selected cities. We trained models using the locations of historical reported flood damage events ( n = 71,434) and a suite of geospatial predictors (e.g., flood severity, climate, socio-economic exposure, topographic variables, soil properties, and hydrologic characteristics). We developed independent models for each hydrologic unit code level 2 watershed and generated a flood damage probability for each 100-m pixel. Our model classified damage or no damage with an average area under the curve accuracy of 0.75; however, model performance varied by environmental conditions, with certain land cover classes (e.g., forest) resulting in higher error rates than others (e.g., wetlands). Our results identified flood damage probability hotspots across multiple spatial and regional scales, with high probabilities common in both inland and coastal regions. The highest flood damage probabilities tended to be in areas of low elevation, in close proximity to streams, with extreme precipitation, and with high urban road density. Given rapid environmental changes, our study demonstrates an efficient approach for updating flood damage probability estimates across the nation.

Environmental Research Letters↗
USGS2012

Wildfire effects on source-water quality--Lessons from Fourmile Canyon fire, Colorado, and implications for drinking-water treatment

Forested watersheds provide high-quality source water for many communities in the western United States. These watersheds are vulnerable to wildfires, and wildfire size, fire severity, and length of fire season have increased since the middle 1980s (Westerling and others, 2006). Burned watersheds are prone to increased flooding and erosion, which can impair water-supply reservoirs, water quality, and drinking-water treatment processes. Limited information exists on the degree, timing, and duration of the effects of wildfire on water quality, making it difficult for drinking-water providers to evaluate the risk and develop management options. In order to evaluate the effects of wildfire on water quality and downstream ecosystems in the Colorado Front Range, the U.S. Geological Survey initiated a study after the 2010 Fourmile Canyon fire near Boulder, Colorado. Hydrologists frequently sampled Fourmile Creek at monitoring sites upstream and downstream of the burned area to study water-quality changes during hydrologic conditions such as base flow, spring snowmelt, and summer thunderstorms. This fact sheet summarizes principal findings from the first year of research. Stream discharge and nitrate concentrations increased downstream of the burned area during snowmelt runoff, but increases were probably within the treatment capacity of most drinking-water plants, and limited changes were observed in downstream ecosystems. During and after high-intensity thunderstorms, however, turbidity, dissolved organic carbon, nitrate, and some metals increased by 1 to 4 orders of magnitude within and downstream of the burned area. Increases of such magnitude can pose problems for water-supply reservoirs, drinking-water treatment plants, and downstream aquatic ecosystems.

Colorado↗
USGS2025

Science support for recovery of Southwestern Willow Flycatcher (Empidonax traillii extimus) on conserved lands in San Diego County

This document was developed based on the results of scientific research to support management and recovery of the endangered Southwestern Willow Flycatcher ( Empidonax traillii extimus ) and its habitat in San Diego County, California. A migratory species restricted to riparian habitat for breeding, the flycatcher is present in southern California from May to August. The flycatcher has declined over the last several decades primarily in response to habitat loss, and possibly Brown-headed Cowbird ( Molothrus ater ) parasitism. This document compiles and analyzes data collected by USGS scientists on population size, distribution, demography, and breeding habitat condition and uses this information to evaluate potential management options and locations relative to several variables including spatial proximity to currently occupied locations, historical occupation, and potential for restoration that would benefit the flycatcher and expand populations. Location-specific management options and habitat restoration opportunities are ranked based on the contribution of each location to promoting regional flycatcher persistence. The results of these analyses can be used by land and resource managers to develop their habitat management projects and priorities and promote flycatcher recovery.

California↗
USGS2023

The Coastal Carbon Library and Atlas: Open source soil data and tools supporting blue carbon research and policy

Quantifying carbon fluxes into and out of coastal soils is critical to meeting greenhouse gas reduction and coastal resiliency goals. Numerous ‘blue carbon’ studies have generated, or benefitted from, synthetic datasets. However, the community those efforts inspired does not have a centralized, standardized database of disaggregated data used to estimate carbon stocks and fluxes. In this paper, we describe a data structure designed to standardize data reporting, maximize reuse, and maintain a chain of credit from synthesis to original source. We introduce version 1.0.0. of the Coastal Carbon Library, a global database of 6723 soil profiles representing blue carbon-storing systems including marshes, mangroves, tidal freshwater forests, and seagrasses. We also present the Coastal Carbon Atlas, an R-shiny application that can be used to visualize, query, and download portions of the Coastal Carbon Library. The majority (4815) of entries in the database can be used for carbon stock assessments without the need for interpolating missing soil variables, 533 are available for estimating carbon burial rate, and 326 are useful for fitting dynamic soil formation models. Organic matter density significantly varied by habitat with tidal freshwater forests having the highest density, and seagrasses having the lowest. Future work could involve expansion of the synthesis to include more deep stock assessments, increasing the representation of data outside of the U.S., and increasing the amount of data available for mangroves and seagrasses, especially carbon burial rate data. We present proposed best practices for blue carbon data including an emphasis on disaggregation, data publication, dataset documentation, and use of standardized vocabulary and templates whenever appropriate. To conclude, the Coastal Carbon Library and Atlas serve as a general example of a grassroots F.A.I.R. (Findable, Accessible, Interoperable, and Reusable) data effort demonstrating how data producers can coordinate to develop tools relevant to policy and decision-making.

Global Change Biology↗
USGS2007

Effects of Withdrawals on Ground-Water Levels in Southern Maryland and the Adjacent Eastern Shore, 1980-2005

Ground water is the primary source of water supply in most areas of Maryland?s Atlantic Coastal Plain, including Southern Maryland. The counties in this area are experiencing some of the most rapid growth and development in the State, resulting in an increased demand for ground-water production. The cooperative, basic water-data program of the U.S. Geological Survey and the Maryland Geological Survey has collected long-term observations of ground-water levels in Southern Maryland and parts of the Eastern Shore for many decades. Additional water-level observations were made by both agencies beginning in the 1970s, under the Power Plant Research Program of the Maryland Department of Natural Resources. These long-term water levels commonly show significant declines over several decades, which are attributed to ground-water withdrawals. Ground-water-level trends since 1980 in major Coastal Plain aquifers such as the Piney Point-Nanjemoy, Aquia, Magothy, upper Patapsco, lower Patapsco, and Patuxent were compared to water use and withdrawal data. Potentiometric surface maps show that most of the declines in ground-water levels can be directly related to effects from major pumping centers. There is also evidence that deep drawdowns in some pumped aquifers may be causing declines in adjacent, unpumped aquifers. Water-level hydrographs of many wells in Southern Maryland show linear declines in levels year after year, instead of the gradual leveling-off that would be expected as the aquifers equilibrate with pumping. A continual increase in the volumes of water being withdrawn from the aquifers is one explanation for why they are not reaching equilibrium. Although reported ground-water production in Southern Maryland has increased somewhat over the past several decades, the reported increases are often not large enough to account for the observed water-level declines. Numerical modeling simulations indicate that a steady, annual increase in the number of small wells could account for the observed aquifer behavior. Such wells, being pumped at rates below the minimum legal reporting threshold of 10,000 gallons per day, might be the source of the additional withdrawals. More detailed water-use data, especially from domestic wells, central-pivot irrigation wells, and other small users not currently reporting withdrawals to the State, may help to determine the cause of the aquifer declines.

Scientific Investigations Report↗
USGS2018

Origin of last-glacial loess in the western Yukon-Tanana Upland, central Alaska, USA

Loess is widespread over Alaska, and its accumulation has traditionally been associated with glacial periods. Surprisingly, loess deposits securely dated to the last glacial period are rare in Alaska, and paleowind reconstructions for this time period are limited to inferences from dune orientations. We report a rare occurrence of loess deposits dating to the last glacial period, ~19 ka to ~12 ka, in the Yukon-Tanana Upland. Loess in this area is very coarse grained (abundant coarse silt), with decreases in particle size moving south of the Yukon River, implying that the drainage basin of this river was the main source. Geochemical data show, however, that the Tanana River valley to the south is also a likely distal source. The occurrence of last-glacial loess with sources to both the south and north is explained by both regional, synoptic-scale winds from the northeast and opposing katabatic winds that could have developed from expanded glaciers in both the Brooks Range to the north and the Alaska Range to the south. Based on a comparison with recent climate modeling for the last glacial period, seasonality of dust transport may also have played a role in bringing about contributions from both northern and southern sources.

Alaska↗
USGS2018

Rapid crop cover mapping for the conterminous United States

Timely crop cover maps with sufficient resolution are important components to various environmental planning and research applications. Through the modification and use of a previously developed crop classification model (CCM), which was originally developed to generate historical annual crop cover maps, we hypothesized that such crop cover maps could be generated rapidly during the growing season. Through a process of incrementally removing weekly and monthly independent variables from the CCM and implementing a ‘two model mapping’ approach, we found it viable to generate conterminous United States-wide rapid crop cover maps at a resolution of 250 m for the current year by the month of September. In this approach, we divided the CCM model into one ‘crop type model’ to handle the classification of nine specific crops and a second, binary model to classify the presence or absence of ‘other’ crops. Under the two model mapping approach, the training errors were 0.8% and 1.5% for the crop type and binary model, respectively, while test errors were 5.5% and 6.4%, respectively. With spatial mapping accuracies for annual maps reaching upwards of 70%, this approach demonstrated a strong potential for generating rapid crop cover maps by the 1 st of September.

Scientific Reports↗
USGS2013

Diablotin Pterodroma hasitata : a biography of the endangered Black-capped Petrel

The Black-capped Petrel Pterodroma hasitata was believed extinct throughout much of the 20th century. It is the only gadfly petrel currently known to breed in the Caribbean Basin. Now seriously endangered, the species is presumed extirpated from Martinique, Dominica, and Guadeloupe, and breeding populations currently occur only on Hispaniola and perhaps Cuba. A related form (now considered a full species) once bred, but is now apparently extinct, on Jamaica. The Black-capped Petrel breeding population may number as few as 500 breeding pairs. Remaining populations suffer from multiple threats to terrestrial and pelagic habitats, including harvest by humans and predation by introduced mammals. The exact sizes, locations, and detailed chronologies of all Black-capped Petrel breeding sites remain poorly studied, although major colonies are today apparently restricted to steep sea and inland cliffs along the La Selle Ridge in Hispaniola. The largest known breeding population occurs in Haiti, although there is continued discussion about a possible breeding site in Cuba in the Sierra Maestra mountain range. Accounts from Cuba are based on the unverified assumption that birds observed at sea just offshore of that island are breeding locally. All evidence at present indicates that waters in or adjacent to the Florida Current and the Gulf Stream between north Florida and southern Virginia provide the primary foraging range of Black-capped Petrels. A small foraging area just off of southeast Cuba has also been reported, but the extent and seasonal use of this area are unknown. Concentrations of birds can be found along the Gulf Stream in southeastern US waters throughout the year, but are particularly common in May, August, and late December through early January. Concentrations of adult birds during winter, when peak breeding activity is underway, suggest that breeding birds forage along the Gulf Stream while commuting to and from breeding colonies. Such long-distance foraging is certainly possible for Pterodroma species. Potential threats to Black-capped Petrels include introduced predators, human encroachment on breeding and foraging habitats, and offshore oil, gas, and wind energy development. Increased mercury levels associated with petroleum production also pose a potential threat, as the Black-capped Petrel seems to be highly susceptible to mercury bioaccumulation compared with other pelagic species. In addition, fires and other bright light sources are known to attract Black-capped Petrels, making collisions with wires and other structures on lighted ships and platforms a potential concern. Haitian social-economic instability and increasing habitat loss suggest the likelihood of further population declines and increasing vulnerability of the species to extinction. Our findings are in accord with the recent decision by the US Fish and Wildlife Service (USFWS) to evaluate the need for additional protection of the species and the primary foraging habitat off the southeastern United States under the Endangered Species Act (USFWS 2012). Additional conservation measures and research strategies that warrant further consideration include (1) protection, monitoring, and management of known breeding populations and nesting habitat in the Dominican Republic and Haiti through controlling predators, installing artificial nest burrows in appropriate sites and hiring local wardens at breeding sites during the nesting season; (2) local and regional training, education and public awareness (e.g. Blanchard & Nettleship 1992); (3) restoration of the original common name Diablotin to common usage to promote the historical and cultural importance of this species; (4) studies to determine the distribution and genetic variability in the remaining populations; and (5) studies of satellite-tagged birds to assess their seasonal and geographic use of pelagic habitats.

Marine Ornithology: Journal of Seabird Research an↗