SEARCH · Geology Reports

Results for “Community Science”

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

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources

USGS2022

PCB exposure is associated with reduction of endosymbionts in riparian spider microbiomes

Microbial communities, including endosymbionts, play diverse and critical roles in host biology and reproduction, but contaminant exposure may cause an imbalance in the microbiome composition with subsequent impacts on host health. Here, we examined whether there was a significant alteration of the microbiome community within two taxa of riparian spiders (Tetragnathidae and Araneidae) from a site with historical polychlorinated biphenyl (PCB) contamination in southern Ontario, Canada. Riparian spiders specialize in the predation of adult aquatic insects and, as such, their contaminant levels closely track those of nearby aquatic ecosystems. DNA from whole spiders from sites with either low or high PCB contamination was extracted, and spider microbiota profiled by partial 16S rRNA gene amplicon sequencing. The most prevalent shift in microbial communities we observed was a large reduction in endosymbionts in spiders at the high PCB site. The abundance of endosymbionts at the high PCB site was 63 % and 98 % lower for tetragnathids and araneids, respectively, than at the low PCB site. Overall, this has potential implications for spider reproductive success and food webs, as riparian spiders are critical gatekeepers of energy and material fluxes at the land-water interface.

Science of the Total Environment↗

USGS2025

Sulfate reduction drives elevated methylmercury formation in water column of eutrophic freshwater lake

Mercury (Hg) contamination of aquatic food webs is controlled in part by the formation and accumulation of toxic and bioaccumulative methylmercury (MeHg). MeHg production is mediated by metabolically diverse microorganisms carrying the hgcAB gene pair, while the demethylation reaction is mediated by several biotic and abiotic processes. However, the relative importance of these two processes on MeHg accumulation and the environmental factors that influence them are poorly characterized, especially in eutrophic environments. In this study, both Hg methylation and MeHg demethylation in a eutrophic freshwater lake were linked to ambient MeHg concentrations and hgcA abundance and expression. High methylation rate potentials indicated in situ MeHg formation was a key source of MeHg to the water column, driven by high hgcA abundance and transcription. Molybdate treatment decreased methylation rate potentials, highlighting the importance of sulfate reduction in driving MeHg formation. Sulfate-reducing bacteria accounted for over 50% of the hgcA gene transcription, despite representing less than 10% of the hgcA -carrying microbial community. An arsR -like transcriptional regulator preceded many hgcA sequences; these were transcriptionally active and linked to lower hgcA expression. Overall, this study elucidates the microbial and biogeochemical processes that influence the in situ formation of MeHg in understudied eutrophic freshwater environments.

Wisconsin↗

USGS2008

Effects of past logging and grazing on understory plant communities in a montane Colorado forest

Throughout Pinus ponderosa-Pseudotsuga menziesii forests of the southern Colorado Front Range, USA, intense logging and domestic grazing began at the time of Euro-American settlement in the late 1800s and continued until the early 1900s. We investigated the long-term impacts of these settlement-era activities on understory plant communities by comparing understory composition at a historically logged and grazed site to that of an environmentally similar site which was protected from past use. We found that species richness and cover within functional groups rarely differed between sites in either upland or riparian areas. Multivariate analyses revealed little difference in species composition between sites on uplands, though compositional differences were apparent in riparian zones. Our findings suggest that settlement-era logging and grazing have had only minor long-term impacts on understories of upland Front Range P. ponderosa-P. menziesii forests, though they have had a greater long-term influence on riparian understories, where these activities were likely the most intense. ?? 2008 Springer Science+Business Media B.V.

Plant Ecology↗

USGS2013

Public-policy issues associated with the SAFRR Tsunami Scenario

The SAFRR (Science Application for Risk Reduction) tsunami scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). In addition to the work performed by the authors on public-policy issues associated with the SAFRR tsunami scenario, this section of the scenario also reflects the policy discussions of the State of California’s Tsunami Policy Work Group, a voluntary advisory body formed in October 2011, which operates under the California Natural Resources Agency (CNRA), Department of Conservation, and is charged with identifying, evaluating, and making recommendations to resolve issues that are preventing full and effective implementation of tsunami hazard mitigation and risk reduction throughout California’s coastal communities. It also presents the analyses of plans and hazard policies of California’s coastal counties, incorporated cities, and major ports performed by the staff of the California Geological Survey (CGS) and Lauren Prehoda, Office of Environmental and Government Affairs, California Department of Conservation. It also draws on the policy framework and assessment prepared for the ARkStorm Pacific Coast winter storm and catastrophic flooding (Topping and others, 2010).

Open-File Report↗

USGS2019

Climate change adaptation for coastal national wildlife refuges

National Wildlife Refuges (NWRs) along the East Coast of the United States protect habitat for a host of wildlife species, while also offering storm surge protection, improving water quality, supporting nurseries for commercially important fish and shellfish, and providing recreation opportunities for coastal communities. Yet in the last century, coastal ecosystems in the eastern U.S. have been severely altered by human development activities as well as sea-level rise and more frequent extreme events related to climate change. These influences threaten the ability of NWRs to protect our nation’s natural resources and to sustain their many beneficial services. Through this project, researchers are collaborating with managers of the North Carolina Coastal Refuges Complex, Cape Romain NWR, South Carolina, and other local interested partners to assist with their long-term planning under uncertain conditions regarding sea-level rise and other global change processes. Researchers are using a variety of state-of-the-art approaches, including formal decision science for systematically analyzing management alternatives and scenario planning methods for engaging with stakeholders to explore possible futures. These approaches are aimed at helping NWR staff develop management objectives, identify and weigh potential management actions for adaptation, and generate decision-support tools and models. Outcomes and products from these efforts will aid managers as they plan for and adapt to the complex challenges facing the NWR system as changing climate and other conditions make their work increasingly more difficult.

Final Project Memorandum↗

USGS2023

An assessment of the relation between metal contaminated sediment and freshwater mussel populations in the Big River, Missouri

The Big River in southeast Missouri drains the largest historical lead mining area in the United States. Ongoing releases of metal contaminated sediments into this river are well documented and are suspected of suppressing freshwater mussel populations. We characterized the spatial extent of metal contaminated sediments and evaluated its relationship with mussel populations in the Big River. Mussels and sediments were collected at 34 sites with potential metal effects and 3 reference sites. Analysis of sediment samples showed that lead (Pb) and zinc (Zn) concentrations were 1.5 to 65 times greater than background concentrations in the reach extending 168 km downstream from Pb mining releases. Mussel abundance decreased acutely downstream from these releases where sediment Pb concentrations were highest and increased gradually as Pb sediment concentrations attenuated downstream. We compared current species richness with historical survey data from three reference rivers with similar physical habitat characteristics and human effects, but without Pb-contaminated sediment. Big River species richness was on average about one-half that expected based on reference stream populations and was 70–75 % lower in reaches with high median Pb concentrations. Sediment Zn and cadmium, and particularly Pb, had significant negative correlations with species richness and abundance. The association of sediment Pb concentrations with mussel community metrics in otherwise high-quality habitat indicates that Pb toxicity is likely responsible for depressed mussel populations observed within the Big River. We used concentration-response regressions of mussel density verses sediment Pb to determine that the Big River mussel community is adversely affected when sediment Pb concentrations are above 166 ppm, the concentration associated with 50 % decreases in mussel density. Based on this assessment of metals concentrations sediment and mussel fauna, our findings indicate that sediment in approximately 140 km of the Big River with suitable habitat has a toxic effect to mussels.

Missouri↗

USGS2016

Microbial community assembly and metabolic function during mammalian corpse decomposition

Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.

Science↗

USGS2025

A review of abrupt permafrost thaw: Definitions, usage, and a proposed conceptual framework

Purpose of Review We review how ‘abrupt thaw’ has been used in published studies, compare these definitions to abrupt processes in other Earth science disciplines, and provide a definitive framework for how abrupt thaw should be used in the context of permafrost science. Recent Findings We address several aspects of permafrost systems necessary for abrupt thaw to occur and propose a framework for classifying permafrost processes as abrupt thaw in the future. Based on a literature review and our collective expertise, we propose that abrupt thaw refers to thaw processes that lead to a substantial persistent environmental change within a few decades. Abrupt thaw typically occurs in ice-rich permafrost but may be initiated in ice-poor permafrost by external factors such as hydrologic change (i.e., increased streamflow, soil moisture fluctuations, altered groundwater recharge) or wildfire. Summary Permafrost thaw alters greenhouse gas emissions, soil and vegetation properties, and hydrologic flow, threatening infrastructure and the cultures and livelihoods of northern communities. The term ‘abrupt thaw’ has emerged in scientific discourse over the past two decades to differentiate processes that rapidly impact large depths of permafrost, such as thermokarst, from more gradual, top-down thaw processes that impact centimeters of near-surface permafrost over years to decades. However, there has been no formal definition for abrupt thaw and its use in the scientific literature has varied considerably. Our standardized definition of abrupt thaw offers a path forward to better understand drivers and patterns of abrupt thaw and its consequences for global greenhouse gas budgets, impacts to infrastructure and land-use, and Arctic policy- and decision-making.

Current Climate Change Reports↗

USGS2024

Perspectives on the future of host-microbe biology from the Council on Microbial Sciences of the American Society for Microbiology

Host-microbe biology (HMB) stands on the cusp of redefinition, challenging conventional paradigms to instead embrace a more holistic understanding of the microbial sciences. The American Society for Microbiology (ASM) Council on Microbial Sciences hosted a virtual retreat in 2023 to identify the future of the HMB field and innovations needed to advance the microbial sciences. The retreat presentations and discussions collectively emphasized the interconnectedness of microbes and their profound influence on humans, animals, and environmental health, as well as the need to broaden perspectives to fully embrace the complexity of these interactions. To advance HMB research, microbial scientists would benefit from enhancing interdisciplinary and transdisciplinary research to utilize expertise in diverse fields, integrate different disciplines, and promote equity and accessibility within HMB. Data integration will be pivotal in shaping the future of HMB research by bringing together varied scientific perspectives, new and innovative techniques, and ’omics approaches. ASM can empower under-resourced groups with the goal of ensuring that the benefits of cutting-edge research reach every corner of the scientific community. Thus, ASM will be poised to steer HMB toward a future that champions inclusivity, innovation, and accessible scientific progress.

mSphere↗

USGS2020

Citizen scientists record novel leaf phenology of invasive shrubs in eastern U.S. forests

Invasive shrubs are an emergent concern in deciduous forests of eastern North America. Their extended leaf phenology (ELP) – earlier leaf emergence and later leaf off compared to native shrubs and the overstory canopy – can simultaneously provide photosynthetic benefits to invasive shrubs while negatively affecting native flora and fauna through providing novel understory shade when the overstory canopy is leafless. However, phenology varies geographically, and the degree to which ELP from local-scale studies applies across the range of forests experiencing shrub invasion is unknown. In partnership with the USA National Phenology Network, we developed a citizen science campaign to record broad patterns of species-specific ELP – an otherwise prohibitively large effort. Using 1,500 observations of 14 species spanning 4 years, we found that the difference in leaf phenology between native and invasive shrubs can exceed 77 days within a growing season, a gap that decreases with increasing latitude by 2.9 [1.6, 4.2] days per degree latitude in the spring, and 2.2 [0.6,1.9] in the fall. Geographic trends in ELP provide a context for interpreting local scale phenology research while bridging inconsistent findings between existing studies and can streamline management by targeting detection and removal of invasive shrubs with leaves while natives are dormant. Furthermore, even small changes to seasonal phenology can impact forest communities, especially if there is a differential response to climate cues by nativity. After exploring broad-scale environmental variables associated with leaf phenology, we find a similar correlation with pre-growing season warmth for native and invasive shrubs, but a different relationship with dormant chill days – a variable less frequently considered for modeling spring phenology for forest productivity.

Biological Invasions↗

USGS2015

Energy flow and the “grassification” of desert shrublands

In our directionally and continuously changing world, history still matters, and it does so in increasingly novel and important ways. Human adaptation to global change will rely heavily on robust baselines of historic environmental variability and detailed understanding of how both past and modern ecosystems have responded to both individual and multiple stressors. The question of global change has motivated an upsurge in paleoecological studies that span the late Quaternary and the modern era, and has inspired a growing consideration of time as a fundamental axis in ecology ( 1 ). A major challenge in developing pertinent ecological baselines remains how to fuse, into continuous time series, observations and experiments from living systems with paleoecological reconstructions from the same sites ( 2 , 3 ). Tracing and disentangling complex responses to environmental stress from paleological to present-day communities is especially daunting; for example, how climate change; accelerated land use; and biological invasions are influencing the flows of water, nutrients, and energy. The paper by Terry and Rowe in PNAS ( 4 ) is a shining example of how modern ecology and paleoecology can be spliced together to decipher how ecological processes unfold over time scales inaccessible to direct observation or experimentation, and how they can be disrupted by human impacts.

Proceedings of the National Academy of Sciences↗

USGS2023

A characterization of the deep-sea coral and sponge community along the Oregon Coast using a remotely operated vehicle on the EXPRESS 2022 expedition

Deep-sea coral and sponge (DSCS) communities serve as essential fish habitat (EFH) by providing shelter and nursery habitat, increasing diversity, and increasing prey availability (Freese and Wing, 2003; Bright, 2007; Baillon et al., 2012; Henderson et al., 2020). Off the U.S. West Coast, threats to these long-lived, fragile organisms from bottom contact fishing gear, potential offshore renewable energy development, and ocean warming and acidification have been the subject of recent research (Gomez et al., 2018; Salgado et al., 2018; Yoklavich, et al., 2018; Gugliotti et al., 2019). Other DSCS studies have reported new species (Yoklavich and Love, 2005), analyzed species distribution and abundance (Tissot et al., 2006, Watters et al., 2022), developed predictive distribution models (Huff et al., 2013; Rooper et al., 2017; Kreidler, 2020), and discovered medicinal uses for corals and sponges (Essack et al., 2011; Shrestha et al., 2018). Due to the vast area of unexplored seafloor within the territorial waters and the U.S. exclusive economic zone (EEZ; 12-200 nautical miles off the coast) and the technological requirements and expense of deep-sea research, there is still much to learn about the distributions and biology of DSCS. This information is critical to resource managers for effective conservation and management of DSCS habitats. In order to minimize the adverse impacts of fishing on EFH, the Pacific Fishery Management Council (PFMC) and National Marine Fisheries Service (NMFS) designated several seafloor habitat areas as EFH conservation areas (EFHCA), first in 2006 (as part of Amendment 19 to the Pacific coast groundfish fishery management plan) and then again in 2020 (as part of Amendment 28). These areas are closed to bottom trawl fishing at a minimum, and in some cases to all bottom contact fishing gears. In addition to protections afforded by EFH-related regulations, the National Marine Sanctuary Program prohibits certain non-fishing activities within areas designated as national marine sanctuaries, such as oil and gas exploration or extraction, cable laying, and other forms of seabed alteration or construction that disturb benthic communities. NOAA’s Deep-Sea Coral and Research Technology Program (DSCRTP) began a 4-yr funding initiative for the U.S. West Coast in 2017. The goals of the West Coast Deep-Sea Coral Initiative (WCDSCI) were to: 1) gather baseline information on areas subject to fishing regulation changes prior to the implementation of Amendment 28; 2) improve our understanding of known DSCS bycatch “hot spots”; and 3) explore and assess DSCS resources within NOAA National Marine Sanctuaries with emphasis on areas of sanctuary resource protection and management concerns. As part of the WCDSCU, an 11-day expedition (3 Sep – 13 Sep 2022) was launched from the NOAA Ship Bell M. Shimada, beginning and ending in Newport, OR. The science team assembled for this cruise were members of the EXpanding Pacific Research and Exploration of Submerged Systems (EXPRESS) campaign, which brings together researchers from federal and nonfederal institutions to collaborate on scientific expeditions targeting the deepwater areas off California, Oregon, and Washington. EXPRESS supports researchers leveraging funding, resources, personnel, and expertise to accomplish more science than would have been possible by a single entity alone. The 2022 expedition included research partners from National Marine Fisheries Service (NMFS) Southwest Fisheries Science Center (SWFSC) and Northwest Fisheries Science Center (NWFSC), Bureau of Ocean Energy Management (BOEM), U.S. Geological Survey (USGS), Pacific Fisheries Management Council Habitat Committee, and Woods Hole Oceanographic Institution.

Report↗

USGS2017

Community tools for cartographic and photogrammetric processing of Mars Express HRSC images

The High Resolution Stereo Camera (HRSC) on the Mars Express orbiter (Neukum et al. 2004) is a multi-line pushbroom scanner that can obtain stereo and color coverage of targets in a single overpass, with pixel scales as small as 10 m at periapsis. Since commencing operations in 2004 it has imaged ~ 77 % of Mars at 20 m/pixel or better. The instrument team uses the Video Image Communication And Retrieval (VICAR) software to produce and archive a range of data products from uncalibrated and radiometrically calibrated images to controlled digital topographic models (DTMs) and orthoimages and regional mosaics of DTM and orthophoto data (Gwinner et al. 2009; 2010b; 2016). Alternatives to this highly effective standard processing pipeline are nevertheless of interest to researchers who do not have access to the full VICAR suite and may wish to make topographic products or perform other (e. g., spectrophotometric) analyses prior to the release of the highest level products. We have therefore developed software to ingest HRSC images and model their geometry in the USGS Integrated Software for Imagers and Spectrometers (ISIS3), which can be used for data preparation, geodetic control, and analysis, and the commercial photogrammetric software SOCET SET (® BAE Systems; Miller and Walker 1993; 1995) which can be used for independent production of DTMs and orthoimages. The initial implementation of this capability utilized the then-current ISIS2 system and the generic pushbroom sensor model of SOCET SET, and was described in the DTM comparison of independent photogrammetric processing by different elements of the HRSC team (Heipke et al. 2007). A major drawback of this prototype was that neither software system then allowed for pushbroom images in which the exposure time changes from line to line. Except at periapsis, HRSC makes such timing changes every few hundred lines to accommodate changes of altitude and velocity in its elliptical orbit. As a result, it was necessary to split observations into blocks of constant exposure time, greatly increasing the effort needed to control the images and collect DTMs. Here, we describe a substantially improved HRSC processing capability that incorporates sensor models with varying line timing in the current ISIS3 system (Sides 2017) and SOCET SET. This enormously reduces the work effort for processing most images and eliminates the artifacts that arose from segmenting them. In addition, the software takes advantage of the continuously evolving capabilities of ISIS3 and the improved image matching module NGATE (Next Generation Automatic Terrain Extraction, incorporating area and feature based algorithms, multi-image and multi-direction matching) of SOCET SET, thus greatly reducing the need for manual editing of DTM errors. We have also developed a procedure for geodetically controlling the images to Mars Orbiter Laser Altimeter (MOLA) data by registering a preliminary stereo topographic model to MOLA by using the point cloud alignment ( pc_align ) function of the NASA Ames Stereo Pipeline (ASP; Moratto et al. 2010). This effectively converts inter-image tiepoints into ground control points in the MOLA coordinate system. The result is improved absolute accuracy and a significant reduction in work effort relative to manual measurement of ground control. The ISIS and ASP software used are freely available; SOCET SET, is a commercial product. By the end of 2017 we expect to have ported our SOCET SET HRSC sensor model to the Community Sensor Model (CSM; Community Sensor Model Working Group 2010; Hare and Kirk 2017) standard utilized by the successor photogrammetric system SOCET GXP that is currently offered by BAE. In early 2018, we are also working with BAE to release the CSM source code under a BSD or MIT open source license.

The International Archives of the Photogrammetry, ↗

USGS1984

Effects of the herbicide glyphosate on avian community structure in the Oregon coast range

A study was conducted on vegetative changes induced by the herbicide glyphosate, and the resultant habitat use of birds nesting on two clearcuts in western Oregon. About 23 percent of total plant cover was initially damaged by aerial application of glyphosate. Most measures of vegetation on the treated site decreased relative to the untreated site 1 year after glyphosate application. By 2 years post-spray, vegetation on the treated site had recovered to near pre-spray status. No difference in density of the bird community was evident between treated and untreated sites during all years of study although individual species densities were modified. Several bird species decreased their use of shrub cover, and increased their use of deciduous trees 1 year after treatment. By 2 years post-spray, many species had returned to pre-spray use of most measured habitat components. Results indicated that application of glyphosate can modify the density and habitat use of birds.

Forest Science↗

USGS2007

Large-scale causes of variation in the serpentine vegetation of California

Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this important flora, we analyzed broad-scale community patterns and environmental conditions in a geographically stratified set of samples from across the state. We considered three major classes of environmental influences: climate (especially precipitation), soils (especially the Mg2+/Ca2+ ratio), and the indirect influences of climate on soils. We used ordination to identify the major axes of variation in common species abundances, structural equation models to analyze the relationship of community axes and endemic and exotic species richness to the environment, and group analysis techniques to identify consistent groupings of species and characterize their properties. We found that community variation could be explained by a two-axis ordination. One axis ranged from conifer forest to grassland and was strongly related to precipitation. The second axis ranged from chaparral to grassland and had little relationship to current environmental conditions, suggesting a possible role for successional history. Precipitation and elevation were respectively the largest influences on endemic and exotic richness, followed by Mg 2+/Ca2+. The results also support the idea that long-term precipitation patterns have altered the Mg2+/Ca2+ ratio via selective leaching, resulting in indirect influences on endemics (positive) and exotics (negative) but not affecting the abundances of common species. We discuss implications of these findings for the conservation of the California serpentine flora. ?? 2007 Springer Science+Business Media B.V.

Conference Paper↗

USGS2015

Archive of sediment data from vibracores collected in 2010 offshore of the Mississippi barrier islands

In 2010, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center collected sediment cores from coastal waters offshore of the Mississippi barrier islands. With funding support from the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project, 65 subaqueous sediment cores were collected over an area of 480 square kilometers (km 2 ), from Ship Island to Petit Bois Island Pass, Mississippi, within the boundary of Gulf Islands National Seashore. This represents only a fraction of the total area encompassed by the NGOM project, which extends from Sabine Lake, Louisiana, to Perdido Bay, Alabama. The primary objectives of the NGOM project are to understand the evolution of coastal ecosystems on the northern gulf coast, the impact of human activities on these ecosystems, and the vulnerability of ecosystems and human communities to more frequent and intense hurricanes in the future. Selection of the core site locations was based on geophysical surveys conducted around the islands from 2008 to 2010. The surveys, using acoustic systems to image and interpret the nearsurface stratigraphy, were conducted to investigate the geologic controls on island evolution. This data series serves as an archive of sediment data collected from August to September 2010, offshore of the Mississippi barrier islands. Data products, including descriptive core logs, core photographs, results of sediment grain-size analyses, sample location maps, and geographic information system (GIS) data files with accompanying formal Federal Geographic Data Committee (FDGC) metadata can be downloaded from the data products and downloads page.

Mississippi↗

USGS2001

HAZUS 99 estimated annualized earthquake losses for the United States

Recent earthquakes around the world show a pattern of steadily increasing damages and losses. The increases are due primarily to two factors: 1) significant growth in urban areas that are prone to earthquakes; and 2) the vulnerability of the older building stock, even buildings that were constructed within the past twenty years. In the United States, earthquake risk has grown substantially with development, while the earthquake hazard has remained relatively constant. To understand the hazard, we study earthquake characteristics and locales in which they occur. To understand risk, we must include characteristics of the built environment in the locales where earthquakes occur, and we must assess potential damages to the built environment and the people who use it. That is a complex undertaking and one this study intends to advance. It is important to estimate the varying degrees of seismic risk throughout the United States because we need that understanding in order to make informed decisions on mitigation policies, priorities, strategies and funding levels—in both the public and private sectors. We can reduce earthquake losses to older buildings by rehabilitating them, and we can reduce earthquake losses in new buildings by applying seismic codes to their design and construction. However, decisions to spend money on either of those solutions require evidence of risk. In the absence of a nationally accepted criterion and methodology for comparing seismic risk across regions, a consensus on optimal mitigation approaches has been difficult to reach. We are all aware of regions with high hazard and high risk, such as Los Angeles, but there is growing recognition that some regions with low seismic hazard actually have high seismic risk, as is the case in New York City and Boston. This risk results, in part, from concentrations of buildings and infrastructure built without use of seismic codes or provisions. Additionally, mitigation policies and practices in the public and private sectors may not have been adopted because a community’s earthquake risk was not clearly demonstrated, and neither was the value of mitigation measures in reducing that risk. The low hazard/high risk problem exists in a number of areas in the U.S., where the infrequency of damaging earthquakes has been interpreted, wrongly, as lack of risk. While earth scientists work to increase knowledge about the hazard throughout the United States, structural engineers and other professionals work to enumerate the many factors that comprise risk. This study is one result of that endeavor. It is based on loss estimates generated by Hazards U.S. (HAZUS), a Geographic Information System (GIS)- based earthquake loss estimation tool, developed by the Federal Emergency Management Agency (FEMA) in cooperation with the National Institute of Building Sciences (NIBS). The HAZUS tool provides an approach to quantifying future earthquake losses that is national in scope, uniform in application, and comprehensive in its coverage of the built environment.

Report↗

USGS2019

Probabilistic relationships between acid-base chemistry and fish assemblages in streams of the western Adirondack Mountains, New York, USA

Surface waters across much of the Adirondacks of New York were acidified in the late 20th century but began to recover after the 1990 amendments to the Clean Air Act. Little data, however, were available to characterize biological impacts and predict recovery of fish assemblages in regional streams. Quantitative fish and chemistry surveys were completed in 47 headwater streams during summer 2014-16 to develop logistic (probabilistic) models that characterize the status of contemporary fish assemblages and predict how different N and S deposition loads may affect future fish assemblages. Models for Ali and richness ≥1 species, ANC and total density >400 fish/0.1 ha, ANC and total biomass >1500 g/0.1, presence of Brook Trout, trout density >200 fish/0.1 ha, and trout biomass >1000 g/0.1 ha were suitable for evaluating community and population responses to changes in acid-base chemistry. Anticipated changes in national (US) secondary standards for atmospheric emissions of NOx and SOx to achieve target N and S deposition loads will alter acid-base chemistry and the probabilities for observing various levels of fish metrics in streams across the region and elsewhere.

New York↗