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USGS2016

A cellular automata downscaling based 1 km global land use datasets (2010–2100)

Global climate and environmental change studies require detailed land-use and land-cover(LULC) information about the past, present, and future. In this paper, we discuss a methodology for downscaling coarse-resolution (i.e., half-degree) future land use scenarios to finer (i.e., 1 km) resolutions at the global scale using a grid-based spatially explicit cellular automata (CA) model. We account for spatial heterogeneity from topography, climate, soils, and socioeconomic variables. The model uses a global 30 m land cover map (2010) as the base input, a variety of biogeographic and socioeconomic variables, and an empirical analysis to downscale coarse-resolution land use information (specifically urban, crop and pasture). The output of this model offers the most current and finest-scale future LULC dynamics from 2010 to 2100 (with four representative concentration pathway (RCP) scenarios—RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5) at a 1 km resolution within a globally consistent framework. The data are freely available for download, and will enable researchers to study the impacts of LULC change at the local scale.

Science Bulletin↗

USGS2014

Estimates of natural salinity and hydrology in a subtropical estuarine ecosystem: implications for Greater Everglades restoration

Disruption of the natural patterns of freshwater flow into estuarine ecosystems occurred in many locations around the world beginning in the twentieth century. To effectively restore these systems, establishing a pre-alteration perspective allows managers to develop science-based restoration targets for salinity and hydrology. This paper describes a process to develop targets based on natural hydrologic functions by coupling paleoecology and regression models using the subtropical Greater Everglades Ecosystem as an example. Paleoecological investigations characterize the circa 1900 CE (pre-alteration) salinity regime in Florida Bay based on molluscan remains in sediment cores. These paleosalinity estimates are converted into time series estimates of paleo-based salinity, stage, and flow using numeric and statistical models. Model outputs are weighted using the mean square error statistic and then combined. Results indicate that, in the absence of water management, salinity in Florida Bay would be about 3 to 9 salinity units lower than current conditions. To achieve this target, upstream freshwater levels must be about 0.25 m higher than indicated by recent observed data, with increased flow inputs to Florida Bay between 2.1 and 3.7 times existing flows. This flow deficit is comparable to the average volume of water currently being diverted from the Everglades ecosystem by water management. The products (paleo-based Florida Bay salinity and upstream hydrology) provide estimates of pre-alteration hydrology and salinity that represent target restoration conditions. This method can be applied to any estuarine ecosystem with available paleoecologic data and empirical and/or model-based hydrologic data.

Florida↗

USGS2007

Remotely Sensed Data Collections: Offerings from EROS

The U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) maintains a wide variety of remotely sensed data collections that contain a wealth of information about the Earth’s land surfaces. Acquired by special sensors carried aboard civilian satellites and aircraft, the images and other data in these collections provide a unique perspective of the terrestrial environment. They represent invaluable resources for scientists, resource managers, policy makers, and educators to use in studying such things as natural hazards, conservation issues, land use and economic development, and environmental change at local, regional, and global levels. Different types of sensors record different types of information, resulting in diverse data products, each with its own particular strengths. Highlighted here are eight remotely sensed data collections that are currently available from EROS.

Fact Sheet↗

USGS2008

Comparison of storage capacity and sedimentation trends of Lago Guayabal, Puerto Rico-December 2001 and October 2006

Lago Guayabal dam is located on the Río Jacaguas in the municipality of Villalba in southern Puerto Rico, about 4 kilometers north of the town of Juana Díaz and about 5 kilometers south of Villalba (fig. 1). The dam is owned and operated by the Puerto Rico Electric Power Authority (PREPA) and was constructed in 1913 for the irrigation of croplands in the southern coastal plains of Puerto Rico. The reservoir impounds the waters of the Río Jacaguas and those of the Río Toa Vaca, when the Toa Vaca dam overflows or releases water. The reservoir has a drainage area of 53.8 square kilometers. The dam is a concrete gravity structure with a normal pool (at top of flashboards) elevation of 103.94 meters above mean sea level (Puerto Rico Electric Power Authority, 1988). During October 2006, the U.S. Geological Survey (USGS), Caribbean Water Science Center, in cooperation with the Puerto Rico Aqueduct and Sewer Authority (PRASA) conducted a bathymetric survey of Lago Guayabal to update the reservoir storage capacity and actualize the reservoir sedimentation rate by comparing the 2006 data with the previous 2001 bathymetric survey results. The purpose of this report is to describe and document the USGS sedimentation survey conducted at Lago Guayabal during October 2006, including the methods used to update the reservoir storage capacity, sedimentation rates, and areas of substantial sediment accumulation since December 2001. The Lago Guayabal sedimentation history up to 2001 was published by the USGS in 2003 (Soler-López, 2003); therefore, this report focuses on the comparison between the 2001 and current bathymetric surveys of Lago Guayabal..

Puerto Rico↗

USGS2008

Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas

Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. ?? 2008 Springer Science+Business Media, LLC.

Ecotoxicology↗

USGS2015

Updating the USGS seismic hazard maps for Alaska

The U.S. Geological Survey makes probabilistic seismic hazard maps and engineering design maps for building codes, emergency planning, risk management, and many other applications. The methodology considers all known earthquake sources with their associated magnitude and rate distributions. Specific faults can be modeled if slip-rate or recurrence information is available. Otherwise, areal sources are developed from earthquake catalogs or GPS data. Sources are combined with ground-motion estimates to compute the hazard. The current maps for Alaska were developed in 2007, and included modeled sources for the Alaska-Aleutian megathrust, a few crustal faults, and areal seismicity sources. The megathrust was modeled as a segmented dipping plane with segmentation largely derived from the slip patches of past earthquakes. Some megathrust deformation is aseismic, so recurrence was estimated from seismic history rather than plate rates. Crustal faults included the Fairweather-Queen Charlotte system, the Denali–Totschunda system, the Castle Mountain fault, two faults on Kodiak Island, and the Transition fault, with recurrence estimated from geologic data. Areal seismicity sources were developed for Benioff-zone earthquakes and for crustal earthquakes not associated with modeled faults. We review the current state of knowledge in Alaska from a seismic-hazard perspective, in anticipation of future updates of the maps. Updated source models will consider revised seismicity catalogs, new information on crustal faults, new GPS data, and new thinking on megathrust recurrence, segmentation, and geometry. Revised ground-motion models will provide up-to-date shaking estimates for crustal earthquakes and subduction earthquakes in Alaska.

Quaternary Science Reviews↗

USGS2021

Bomb-produced radiocarbon across the South Pacific Gyre — A new record from American Samoa with utility for fisheries science

Coral skeletal structures can provide a robust record of nuclear bomb produced 14 C with valuable insight into air-sea exchange processes and water movement with applications to fisheries science. To expand these records in the South Pacific, a coral core from Tutuila Island, American Samoa was dated with density band counting covering a 59-yr period (1953–2012). Seasonal signals in elemental ratios (Sr/Ca and Ba/Ca) and stable carbon (δ 13 C) values across the coral core corroborated the well-defined annual band structure and highlighted an ocean climate shift from the 1997–1998 El Niño. The American Samoa coral 14 C measurements were consistent with other regional records but included some notable differences across the South Pacific Gyre (SPG) at Fiji, Rarotonga, and Easter Island that can be attributed to decadal ocean climate cycles, surface residence times and proximity to the South Equatorial Current. An analysis of the post-peak 14 C decline associated with each coral record indicated 14 C levels are beginning to merge for the SPG. This observation, coupled with otolith measurements from American Samoa, reinforces the perspective that bomb 14 C dating can be performed on fishes and other marine organisms of the region using the post-peak 14 C decline to properly inform fisheries management in the South Pacific.

Radiocarbon↗

USGS2004

Are brook trout streams in Western Virginia and Shenandoah National Park recovering from acidification?

Streamwater composition data obtained through periodic sampling of streams that support brook trout ( Salvelinus fontinalis ) in the mountains of western Virginia were examined for evidence of recovery from acidification during the 1988−2001 period. Measurements of sulfate deposition in precipitation indicate that sulfate deposition in the region declined approximately 40% between 1985 and 2000. While no significant regional trends in acid−base constituents were observed for the set ( n = 65) of western Virginia study streams, significant regional trends were observed for a subset ( n = 14) of streams in Shenandoah National Park (SNP). For the subset of SNP streams, the median increase in acid-neutralizing capacity (ANC) was 0.168 μequiv L -1 year -1 and the median decrease in sulfate concentration was −0.229 μequiv L -1 year -1 . Although these trends are consistent with recovery from acidification, the degree of apparent recovery is small compared to estimates of historic acidification in SNP streams and much less than observed in other, more northern regions in the United States. Correlation between sulfate concentration trends and current sulfate concentrations in streamwater suggests that recovery from stream acidification in the western Virginia region is determined by sulfur retention processes in watershed soils. A transient increase in nitrate concentrations that occurred among some western Virginia streams following forest defoliation by the gypsy moth ( Lymantria dispar ) complicates interpretation of the observed patterns of change in acid−base status.

Virginia↗

USGS1990

Surface and airborne evidence for plumes and winds on Triton

Aeolian features on Triton that were imaged during the Voyager Mission have been grouped. The term "aeolian feature" is broadly defined as features produced by or blown by the wind, including surface and airborne materials. Observations of the latitudinal distributions of the features probably associated with current activity (known plumes, crescent streaks, fixed terminator clouds, and limb haze with overshoot) all occur from latitude -37° to latitude -62°. Likely indicators of previous activity (dark surface streaks) occur from latitude -5° to -70°, but are most abundant from -15° to -45°, generally north of currently active features. Those indicators which give information on wind direction and speed have been measured. Wind direction is a function of altitude. The predominant direction of the surface wind streaks is found to be between 40° and 80° measured clockwise from north. The average orientation of streaks in the northeast quadrant is 59°. Winds at 1- to 3-kilometer altitude are eastward, while those at >8 kilometers blow west.

Science↗

USGS2021

New faunal records from a World Heritage Site in danger: Rennell Island, Solomon Islands

Remote oceanic islands have high potential to harbor unique fauna and flora, but opportunities to conduct in-depth biotic surveys are often limited. Furthermore, underrepresentation of existing biodiversity in the literature has the potential to detract from conservation planning and action. Between 18 and 29 October 2018, we surveyed the terrestrial vertebrates of East Rennell, a UNESCO World Heritage Site in Solomon Islands. We documented 56 species, including 15 squamates, 13 mammals, and 38 birds, and present four new vertebrate records for the island: Stephan's emerald dove ( Chalcophaps stephani ), Maluku myotis ( Myotis moluccarum ), littoral skink ( Emoia atrocostata ) and brahminy blindsnake ( Indotyphlops braminus ). East Rennell was designated a World Heritage site for its significant on-going ecological and biological processes, and importance for the study of island biogeography. The new records presented here provide evidence that continued field studies combined with DNA analysis will continue to uncover even greater endemic biodiversity. Rennell is currently experiencing major habitat destruction in parts of the island that are not under World Heritage protection, and we anticipate collateral damage will likely extend into protected areas. Our survey also underscores the incredible vertebrate biodiversity that stands to be lost unless conservation actions and local community needs are intertwined to promote beneficial outcomes on both fronts.

Pacific Science↗

USGS2002

U.S. Geological Survey Activities Related to American Indians and Alaska Natives Fiscal Year 2002

Information is a resource for Native American governments, communities, organizations, and people. The U.S. Geological Survey (USGS) provides technical expertise, reports, and other impartial information sources that benefit Native Americans interested in subsistence issues, water, land use, and the health of many parts of the environment. Native self-sufficiency, economic development, and conservation are cultivated through Native decisions informed with USGS data and analyses. The USGS works in cooperation with American Indian and Alaska Native governments, conducting 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, streamflow, biota, and other topics are available to American Indian and Alaska Native individuals and institutions. The USGS recognizes the need to learn from and 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 2002. Some of these USGS activities were carried out in concert with the Bureau of Indian Affairs (BIA). Others were conducted by Tribes, Tribal organizations, professional societies, and the USGS. A growing number of Tribal governments, educational institutions, and other Tribal organizations have begun using geographic information systems and other digital technologies in recent years. As Tribes become more interested in and more adept at managing digital information, they are seeking relevant data from the USGS more frequently. Using digital technologies provides Tribal governments with additional means of managing lands and resources for the benefit of current and future generations. The USGS recognizes the need to make its information available to Tribal governments, and to work with those governments and other institutions to advance data management capabilities. The USGS also recognizes that Tribal institutions have varying needs, interests, and capacities. The USGS strives to be sensitive to the unique circumstances of each of these institutions while supporting their self-driven evolution. The USGS is responding to these needs by increasing the transfer of scientific information to American Indian and Alaska Native governments and by training employees of those governments to conduct scientific studies and improve scientific data management. The USGS is also encouraging American Indians and Alaska Natives to pursue careers in science and seeking ways to hire Indian and Native students. By identifying, improving, and disseminating information about available hiring mechanisms, the USGS is working to make hiring such students easier, and, therefore, more likely, for USGS managers. The U.S. Geological Survey is the Federal science bureau within the Department of the Interior (DoI). The USGS is non-regulatory and is not a significant manager of Federal or Trust lands or assets. However, as described in this report, there are several types of USGS activities that involve American Indians, Alaska Natives, and their lands. One type of activity is the course of formal studies, conducted through existing USGS programs, that involves collection of specific types of data as well as investigative and research projects. These projects typically last 2 or 3 years, although a few are parts of longer-term activities. Some projects are funded through cooperative agreements, from monies provided to the USGS by individual Tribal governments, or by the BIA. The USGS provides matching funds for cooperative projects. These formal projects may also receive funding from the U.S. Environmental Protection Agency, the Indian Health Service (part of the Department of Health and Human Services), or other Federal agencies. The USGS routinely works with its sister bureaus in the Department of the Interior to provide the scientific information and expertise needed to meet the Department's science priorities. Within this context, the USGS and the BIA are cooperating to use USGS information resources to benefit American Indian and Alaska Native peoples and their lands. The second type of USGS activity is less formal, based on initiatives designed and conducted by USGS employees. Frequently involving educational activities, these endeavors are prompted by employee interests, often as collateral issues, that result from one or more USGS employees identifying and responding to an observed need. In these activities, USGS employees help fulfill a mission of the USGS--to prove scientific relevance--while helping their fellow citizens. Increasingly, some of the educational activities are becoming parts of formal USGS projects. USGS employees have also taken the initiative in assisting American Indians and Alaska Natives through participation in several organizations that were created to foster awareness of science among Native peoples and to help build support and communication networks. One such group is the American Indian Science and Engineering Society (AISES). This group sponsors an annual national meeting in which USGS employees participate. USGS employees join this organization on a voluntary basis, bringing the benefits of this expanded network to the USGS, as many employees do with other professional organizations. Each part of the USGS has identified an American Indian/Alaska Native liaison. The USGS has a regional organizational structure, with Western, Central, and Eastern Regions. The regions work in concert with specific scientific disciplines to conduct the scientific mission of the USGS. The regional structure is intended to bring us closer to our customers; we hope that Native Americans and Alaska Natives will use the contacts listed at the end of this report.

Report↗

USGS2013

Flood-inundation maps for the Flatrock River at Columbus, Indiana, 2012

Digital flood-inundation maps for a 5-mile reach of the Flatrock River on the western side of Columbus, Indiana, from County Road 400N to the river mouth at the confluence with Driftwood River, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ and the Federal Flood Inundation Mapper Web site at http://wim.usgs.gov/FIMI/FloodInundationMapper.html, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Flatrock River at Columbus (station number 03363900). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service, which also presents the USGS data, at http:/water.weather.gov/ahps/. Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at the Flatrock River streamgage, high-water marks that were surveyed following the flood of June 7, 2008, and water-surface profiles from the current flood-insurance study for the City of Columbus. The hydraulic model was then used to compute 12 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from 9 ft or near bankfull to 20 ft, which exceeds the stages that correspond to both the estimated 0.2-percent annual exceedance probability flood (500-year recurrence interval flood) and the maximum recorded peak flow. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from Light Detection and Ranging (LiDAR) data having a 0.37 ft vertical accuracy and 3.9 ft horizontal resolution) to delineate the area flooded at each water level. The availability of these maps on the USGS Federal Flood Inundation Mapper Web site, along with Internet information regarding current stage from the USGS streamgage, will provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

Indiana↗

USGS1998

Impact of alternative regeneration methods on genetic diversity in coastal Douglas-fir

Genetic implications of natural and artificial regeneration following three regeneration methods (group selection, shelterwood, and clearcut) were investigated in coastal Douglas-fir ( Pseudotsuga menziesii var. menziesii [Mirb.] Franco) using genetic markers (17 allozyme loci). In general, harvesting followed by either natural or artificial regeneration resulted in offspring populations little altered from those in the previous generation. Cutting the smallest trees to form shelterwoods, however, resulted in the removal of rare, presumably deleterious, alleles, such that slightly fewer alleles per locus were observed among residual trees (2.76) and natural regeneration (2.75) than found in uncut (control) stands (2.86). Thus, although the shelterwood regime appears quite compatible with gene conservation, it would be best to leave parent trees of a range of sizes in shelterwoods designated as gene conservation reserves, in order to maximize the number of alleles (regardless of current adaptive value) in naturally regenerated offspring. Seedling stocks used for artificial regeneration in clearcut, shelterwood, and group selection stands (7 total) had significantly greater levels of genetic diversity, on average, than found in natural regeneration. This is probably because the seeds used in artificial seedling stocks came from many wild stands and thus, sampled more diversity than found in single populations. For. Sci. 44(3): 390-396.

Forest Science↗

USGS2023

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2022 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance, 2015; Breed et al., 2018; Winkler et al., 2018; NASEM, 2023). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where low and highly variable precipitation is standard. Providing this information requires synergistic research efforts in which results from earlier investigations inform the design of subsequent investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities to support CPNPP in FY22 followed the FY22 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance, 2015), Biden-Harris Administration Executive Order 14008 (Tackling the Climate Crisis at Home and Abroad), and Department of Interior Priority #4 (Working to conserve at least 30% each of our lands and waters by the year 2030). Research activities in FY22 centered on landscape genomics, monitoring common garden and seeding experiments near Vernal and Moab, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and continuing newer genetics projects to investigate the impact of productions techniques on plant materials and restoration treatments on native plant communities. These activities were supported by two biological science technicians. The effects of the SARS-CoV-2 pandemic were less visible in FY22, allowing SBSC to catch up on backlogged laboratory work. The overall progress of SBSC’s research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY22, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each 5-year plan goal are discussed in turn.

Colorado Plateau↗

USGS2008

An exploration of Bureau of Reclamation approaches for managing conflict over diverging science

As a major institutional agent supplying Western water resources, the Bureau of Reclamation (Reclamation) provides important leadership, technical, and financial resources in water management, serving as the West's "water broker" (Bowersox 2000; Pisani 2003). In recent years, growing numbers of constituencies using water and the over-allocation of water resources have contributed to conflict over the resource in the American West (National Research Council 2004). Although the conflicts arise from many sources, one common theme is that Reclamation managers often must make decisions about water use and allocation when scientific studies provide uncertain or competing recommendations. We conducted a preliminary study of Reclamation water managers and water scientists to try to understand the approaches or techniques they use or consider useful for dealing with scientific conflicts over water allocation and how these compare to techniques found in the relevant literature. We report the results of (1) an electronic survey of Reclamation senior managers and (2) a panel discussion amongst Reclamation senior managers as to the current institutional capabilities for managing diverging scientific findings in water dispute resolution processes. We conclude with a discussion of the strengths and weaknesses of the different tools and techniques managers reported in the survey and in the panel discussion.

Technical Memorandum↗

USGS2017

Flood-inundation maps for the St. Joseph River at Elkhart, Indiana

Digital flood-inundation maps for a 6.6-mile reach of the St. Joseph River at Elkhart, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at https://water.usgs.gov/osw/flood_inundation/ , depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage 04101000, St. Joseph River at Elkhart, Ind. Real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at https://waterdata.usgs.gov/nwis or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at http:/water.weather.gov/ahps/ , which also forecasts flood hydrographs at this site (NWS site EKMI3). Flood profiles were computed for the stream reach by means of a one-dimensional, step-backwater hydraulic modeling software developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated using the current stage-discharge rating at the USGS streamgage 04101000, St. Joseph River at Elkhart, Ind., and the documented high-water marks from the flood of March 1982. The hydraulic model was then used to compute six water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum ranging from 23.0 ft (the NWS “action stage”) to 28.0 ft, which is the highest stage interval of the current USGS stage-discharge rating curve and 1 ft higher than the NWS “major flood stage.” The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from light detection and ranging [lidar] data having a 0.49-ft root mean squared error and 4.9-ft horizontal resolution, resampled to a 10-ft grid) to delineate the area flooded at each stage. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage and forecasted high-flow stages from the NWS, will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Indiana↗

USGS2025

Lunar grid systems, coordinate systems, and map projections for the Artemis missions and lunar surface navigation

Foreward This document contains design specifications of a navigational standard for the Moon, including a Lunar Transverse Mercator system, a Lunar Polar Stereographic system, a Lunar Grid Reference System, and a unique coordinate structure, Artemis Condensed Coordinates, for Artemis mission navigation and lunar surface science. The National Aeronautics and Space Administration (NASA) Artemis campaign seeks to place humans on the Moon for the first time since the Apollo missions. Early Artemis missions are heavily focused on the lunar south pole, which promises to return valuable data on the Moon’s geologic record, amongst other mission objectives. Coordinate systems in use today for the lunar south pole provides crew members on the surface neither an efficient nor intuitive means to communicate their position and orientation. A novel grid coordinate system, the Lunar Grid Reference System, is proposed to address these concerns for use in real-time extravehicular activity operations on the lunar surface. The many stakeholders involved in the Artemis missions will need a common system to communicate position and orientation while astronauts are operating on the lunar surface. To that end, Artemis crew members will need that system to be efficient and intuitive to promote efficient extravehicular activity timelines and reduce confusion. In the context of this document, these characteristics are addressed on the design of lunar coordinate systems: Efficient.—The number of characters required to communicate a location within a desired precision level in both local and global contexts, and how many steps are required for a recipient or sender to interpret a location. Intuitive.—How well the system aligns with human perceptual abilities, and whether the system yields distances that have the same relationship to actual lunar surface distance in all directions from the point where a person is located. Technological systems are currently being investigated to supplement the crew members’ ability to locate and orient themselves and other assets on the lunar surface; however, it is unlikely that those systems will be fully operational for the first few landed missions. Even with future positional aids, crew members will still need an efficient and intuitive means to communicate position and orientation. In addition, if technological systems fail, the crews will require land navigation skills and have maps available, thus providing further motivation for a crew-centric coordinate system. The contents of this U.S. Geological Survey (USGS) document detail a comprehensive framework for standardizing lunar crewed surface navigation within NASA and outlines the protocols, methods, and designs necessary for achieving consistency and interoperability across relevant space mission teams and lunar surface navigators. Key components of this document include designs of map projections, projected coordinate reference systems (Lunar Transverse Mercator and Lunar Polar Stereographic systems), and a grid system (Lunar Grid Reference System and Artemis Condensed Coordinates) for the Moon. The work proposed in this document seeks to accomplish something similar to the National Geospatial-Intelligence Agency (NGA) document SIG 0012 (NGA, 2014a), but for using grid systems for the Moon. This report incorporates initial feedback and input from NASA’s Artemis Geospatial Data Team, NASA’s Flight Operations Directorate, National Geodetic Survey, USGS Astrogeology Science Center, and NGA and is intended to serve as a resource for all involved with the Artemis missions, as well as for engineers designing and operating lunar infrastructure.

Techniques and Methods↗

USGS2013

Zinc isotope fractionation during magmatic differentiation and the isotopic composition of the bulk Earth

he zinc stable isotope system has been successfully applied to many and varied fields in geochemistry, but to date it is still not completely clear how this isotope system is affected by igneous processes. In order to evaluate the potential application of Zn isotopes as a proxy for planetary differentiation and volatile history, it is important to constrain the magnitude of Zn isotopic fractionation induced by magmatic differentiation. In this study we present high-precision Zn isotope analyses of two sets of chemically diverse, cogenetic samples from Kilauea Iki lava lake, Hawaii, and Hekla volcano, Iceland, which both show clear evidence of having undergone variable and significant degrees of magmatic differentiation. The Kilauea Iki samples display small but resolvable variations in Zn isotope composition (0.26‰<δ 66 Zn<0.36‰; δ 66 Zn defined as the per mille deviation of a sample's 66 Zn/ 64 Zn compositional ratio from the JMC-Lyon standard), with the most differentiated lithologies exhibiting more positive δ 66 Zn values. This fractionation is likely a result of the crystallization of olivine and/or Fe–Ti oxides, which can both host Zn in their crystal structures. Samples from Hekla have a similar range of isotopic variation (0.22‰<δ 66 Zn<0.33‰), however, the degree of fractionation caused by magmatic differentiation is less significant (only 0.07‰) and no correlation between isotope composition and degree of differentiation is seen. We conclude that high temperature magmatic differentiation can cause Zn isotope fractionation that is resolvable at current levels of precision, but only in compositionally-evolved lithologies. With regards to primitive (ultramafic and basaltic) material, this signifies that the terrestrial mantle is essentially homogeneous with respect to Zn isotopes. Utilizing basaltic and ultramafic sample analyses, from different geologic settings, we estimate that the average Zn isotopic composition of Bulk Silicate Earth is δ 66 Zn=0.28±0.05‰ (2s.d.).

Earth and Planetary Science Letters↗