Geology topics

Research about United States

Source-linked reports with geographic coverage including United States.

At least 1,621 records · Page 90Linked to original sources

USGS2025

The 3D Elevation Program—Supporting Connecticut's economy

Introduction Connecticut has a diverse, largely forested landscape characterized by hills and low mountains in the Western Upland, hills in the Eastern Upland, ridges and broad valleys in the Central Lowland, and many beaches and harbors along the coast of Long Island Sound. Connecticut is manufacturing and service focused, ranking almost highest among the 50 States in the United States in personal income per capita. Due to Connecticut’s dense population, many people, especially the approximately 60 percent living near the coast, may be affected by climate-driven disasters. High-quality elevation data can inform the activities of many nongovernmental organizations and municipal and academic entities statewide, resulting in substantial economic impact. Government at the State and local levels relies on these data to support regulatory permitting, resource and infrastructure management, and various engineering and planning-level analyses. Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features. The 3D Elevation Program (3DEP) is managed by the U.S. Geological Survey in partnership with Federal, State, Tribal, U.S. territorial, and local agencies to acquire consistent lidar coverage at quality level 2 or better to meet the many needs of the Nation and Connecticut. The status of available and in-progress 3DEP baseline lidar data in Connecticut is shown. 3DEP baseline lidar data include quality level 2 or better, 1-meter or better digital elevation models, and lidar point clouds, and must meet the Lidar Base Specification version 1.2 or newer requirements. The National Enhanced Elevation Assessment identified user requirements and conservatively estimated that availability of lidar data would result in at least $4.40 million in new benefits annually to the State. The top 10 Connecticut business uses for 3D elevation data, which are based on the estimated annual conservative benefits of 3DEP, are shown.

Connecticut↗

USGS2025

Factors associated with survival, recovery, and movements in the western Gulf Coast population of mottled ducks

The mottled duck ( Anas fulvigula ) is nonmigratory and a priority species for regional conservation and management because of its limited range and declining population trajectory in the western Gulf Coast (WGC) of Louisiana and Texas, USA. We developed multistate dead-recovery models for banding and recovery data (1997–2020) to evaluate potential drivers of survival, recovery, and post-summer movements for the WGC population of mottled ducks in Louisiana and Texas. Annual survival was most strongly associated with sex and year, with females having lower survival ( ± = 0.544 ± 0.114) than males (0.619 ± 0.062). Of the 32 environmental covariates tested, fall precipitation was the factor most strongly associated with survival. Conditional recovery probability (i.e., given mortality, the probability a bird had been shot by a hunter, retrieved, and had their band number reported) varied by sex, age, geographic state, and year, with juvenile males generally having highest conditional recovery (0.303 ± 0.072), followed by juvenile females (0.201 ± 0.100), adult males (0.156 ± 0.038), and adult females (0.095 ± 0.057). Estimates of harvest probabilities followed similar patterns as conditional recovery. Models containing effects of harvest regulations on conditional recovery were not competitive compared to models with general year effects; however, post hoc analyses suggested conditional recovery and harvest probabilities for adult and juvenile females decreased with the daily bag limit reduction in Louisiana and, for juvenile females, implementation of the 5-day closure regulation in Texas. Post-summer movement was substantially higher in the direction of Texas to Louisiana, decreased with distance to the Louisiana–Texas border, was higher for males than females, and varied with winter precipitation. These results contribute to a better understanding of the factors influencing demographic performance, harvest, and movement between states with differing harvest regulations and environmental pressures, which is important for mottled duck conservation planning. Wildlife managers can consider expanding banding effort throughout the full range of the WGC population and collecting and reporting live-recapture data to allow for stronger population-level inferences and increased power to detect differences in important demographic parameters at more refined spatial scales.

Louisiana, Texas↗

USGS2025

The functional traits behind fish rarity in an impounded river basin

Reservoirs alter flows and aquatic habitats, reordering rarity patterns of reservoir ichthyofauna by allowing certain fish traits to flourish while filtering others. We reviewed the composition of fish species in an impounded river basin (Tennessee River, USA) to identify traits that influence rarity. We delineate levels of rarity based on the number of occupied reservoirs and species distribution, compare traits across rarity levels, and pinpoint traits that influence species rarity inside reservoirs. Four rarity levels were designated to 212 fish species: absent from the reservoir, rare and restricted within the basin, rare and spread throughout the basin, and common throughout the basin. Common species had the most distinctive traits, suggesting highly filtered species. They exhibited higher fecundity, longevity, piscivory, potamodromy, and association with large woody debris, vegetation, slow current, and lacustrine habitats. Rare and spread and rare and restricted species were separated by a few macrohabitat traits, with the former tending to be more lowland, slow current, large river, and lacustrine-oriented whereas the latter more creek and lotic oriented. Only age at maturity, longevity, fecundity, and potamodromy—all of which were lower in absent species—separated the absent from the rare and restricted. About half of rare and restricted species were already rare and restricted pre-impoundment; the rest had wider distributions pre-impoundment denoting species vulnerable in reservoirs and needing conservation to prevent local extinctions. Signals gleaned from species traits and rarity analysis indicate that conservation of rare species may need to focus on enhancements to selected reservoir habitats and to basin-wide connectivity.

Alabama, Georgia, Kentucky, Tennessee↗

USGS2025

Evidence for petit-spot volcanism in the Puerto Rico Trench

Petit-spot volcanism occurs in intraplate settings along the outer rise of subducting plates. Here we present evidence for petit-spot type of volcanism from multibeam bathymetry and backscatter data from the Puerto Rico Trench (PRT). It is the first report of such volcanism in the Atlantic basin. Up to 34 possible petit-spot volcanic cones are mapped in the eastern section of the PRT, with an average diameter of 950 m and a mean height of 92 m. The seamounts are in a region of the PRT that has the longest and highest bending faults, up to 50.6 km long and 1.49 km high. Some of the volcanic cones are associated with fault scarps. The larger bending fault scarps in the region of the volcanic cones suggest the stress state in the eastern PRT is favorable for allowing asthenospheric melt to escape to the surface.

Puerto Rico Trench↗

USGS2025

Mobile radar provides insights into hydrologic responses in burn areas

Background Wildfires often occur in mountainous terrain, regions that pose substantial challenges to operational meteorological and hydrologic observing networks. Aims A mobile, post-fire hydrometeorological observatory comprising remote-sensing and in situ instrumentation was developed and deployed in a burnt area to provide unique insights into rainfall-induced post-fire hazards. Methods Mobile radar-based rainfall estimates were produced throughout the burn area at 75-m resolution and compared with rain gauge accumulations and basin response variables. Key results The mobile radar was capable of resolving details in intra-basin rain fields as well as detecting storms approaching the burn area with accuracy equivalent to rain gauges. Runoff responses were complex and dependent on spatiotemporal patterns and magnitude of rainfall intensity over the burn area. Conclusions The complement of the mobile radar with the near-field, non-contact instruments measuring the hydrologic response provided valuable information in regions that are difficult to access and are not routinely monitored by conventional observing networks. Implications Post-fire observatories equipped with mobile radars deployed on burn areas provide real-time data, early alerting capabilities and visualizations to potentially guide impact-based decision support for local authorities.

Colorado↗

USGS2025

Forecasting dynamics of a recolonizing wolf population under different management strategies

Species recovery can be influenced by a wide variety of factors, such that predicting the spatiotemporal dynamics of recovering species can be exceedingly difficult. These predictions, however, are valuable for decision makers tasked with managing species and determining their legal status. We applied a spatially explicit projection model to estimate population growth and viability of gray wolves ( Canis lupus ) from 2021 to 2070 in the state of Washington, USA, where wolves have been naturally recolonizing since the establishment of the first resident pack in 2008. Using this model, we predicted the effects of 12 scenarios relating to management actions (e.g., lethal removals by the state agency, translocation, recreational harvest) and system uncertainties (e.g., immigration from out of state, disease) on the probability of meeting Washington's wolf recovery goals, the probability of extinction, and other metrics related to population status. Population recovery was defined under Washington's Wolf Conservation and Management Plan as four breeding pairs in each of three recovery regions and three additional breeding pairs anywhere in the state. The baseline and two translocation scenarios indicated a high (> 90%) probability of wolf recovery in Washington by 2070, but scenarios related to harvest mortality (removal of 5% of the population every 6 months), increased lethal removals (removal of 8.53% of the population across the state each year), and cessation of immigration from out of state resulted in probabilities of < 0.20 (0.01, 0.04, and 0.17, respectively) of meeting recovery goals by 2070. Only two scenarios of 12 (increased harvest and lethal removals scenarios) resulted in a geometric mean of population growth ≤ 1, indicating long-term population stability or growth for most scenarios. Our results suggest that wolves will continue to recolonize Washington and that recovery goals are likely to be met so long as harvest and lethal removals are not at unsustainable levels and adjacent populations support immigration into Washington.

Washington↗

USGS2025

Combining acoustic telemetry and side-scan sonar to estimate abundance of endangered shortnose sturgeon in the Hudson River, New York

For endangered shortnose sturgeon (Acipenser brevirostrum), the ability to estimate and monitor population size is critical for tracking species’ recovery. Yet, contemporary abundance estimates have not been completed for many shortnose sturgeon populations, largely owing to the difficulty in using traditional abundance estimators for sturgeons. Here, we estimate the adult shortnose sturgeon population size of the Hudson River, NY by integrating data from two largely passive sampling methods – acoustic telemetry and side-scan sonar – into a Bayesian hierarchical model of abundance. We estimated the adult abundance to be 69,798 individuals (95% CI = 9,207-185,666), making the Hudson River the largest extant shortnose sturgeon population. Despite this, the population remains vulnerable to localized disturbances, as over 40% of the population congregated in a small overwintering habitat that coincides with an area of high anthropogenic activity. Accordingly, recurrent demographic surveys may be beneficial for gaining insight into the relative effects of anthropogenic and naturally stochastic processes shaping shortnose sturgeon demography. Our modeling framework provides a relatively low-cost alternative for future demographic monitoring of species of conservation concern.

New York↗

USGS2025

Ecological scenarios: Embracing ecological uncertainty in an era of global change

Scenarios, or plausible characterizations of the future, can help natural resource stewards plan and act under uncertainty. Current methods for developing scenarios for climate change adaptation planning are often focused on exploring uncertainties in future climate, but new approaches are needed to better represent uncertainties in ecological responses. Scenarios that characterize how ecological changes may unfold in response to climate and describe divergent and surprising ecological outcomes can help natural resource stewards recognize signs of nascent ecological transformation and identify opportunities to intervene. Here, we offer principles and approaches for more fully integrating ecological uncertainties into the development of future scenarios. We provide examples of how specific qualitative and quantitative methods can be used to explore variation in ecological responses to a given climate future. We further highlight opportunities for ecological researchers to generate actionable projections that capture uncertainty in both climatic and ecological change in meaningful and manageable ways to support climate change adaptation decision making.

Nebraska↗

USGS2025

Insights from megacryst-included zircon dates on the spatial extent of magma mixing in the Tuolumne Intrusive Suite, California, USA

The spatial extent of mixing between separately emplaced batches of magma is a key component in understanding the incremental assembly of plutons. Potassium feldspar megacrysts (>3 cm length) in granodioritic rocks are hypothesized to record magma mixing and transport over hundred kyr timescales. CA-ID-TIMS U-Pb dates from zircon inclusions within 11 new megacryst samples and their surrounding matrix from the Tuolumne Intrusive Suite are presented as a means of evaluating the extent of mixing across a less than two km wide gradational contact. Megacrysts from within the gradational contact yielded zircon dates consistent with mixing or transport from the older porphyritic Half Dome Granodiorite, but the zircon included in megacrysts from the younger Cathedral Peak Granodiorite show no evidence of interaction with the porphyritic Half Dome. These results, along with the trace element geochemistry of the zircon, suggest that the porphyritic Half Dome and Cathedral Peak magmas where we sampled were not comagmatic, which constrains the width of a mixing front to the kilometer scale gradational contact between these units. From within this gradational contact, we do find evidence of mixing consistent with prior studies. Differences between the core- and rim-included zircon date spectra also suggest that protracted growth is recorded in some K-feldspar megacrysts but may not be a requirement for forming them.

California↗

USGS2025

Effects of restoration thinning on live tree carbon in northern secondary coastal redwood forests

At Redwood National and State parks restoration efforts are underway to promote the recovery of forests following a history of intense logging. Unmanaged secondary forests at the parks have high stem density with slow stand development. Restoration thinning treatments of these stands are designed to promote the representation of redwood and improve the growth of residual trees. Restoration treatments, by definition, remove live tree carbon, so there is a potential conflict with restoration and carbon sequestration goals. We used data from 151 monitoring plots to determine early treatment effects (mostly ≤ 10 years following treatments) on live tree forest carbon in thinned and unthinned stands. Aboveground live tree carbon in untreated secondary forests was primarily related to stand age. Both treated and untreated stands accumulated carbon over time, with evidence that treated stands had a slightly faster rate of carbon accumulation. For a subset of plots where we had sufficient replicates of thinning prescriptions, we found thinning resulted in reductions in live tree aboveground carbon, particularly for heavy thinning, but with plots accumulating live tree carbon stocks similar to pre-treatment levels within 6–10 years. Stand projections suggested that both thinned and unthinned stands have the capacity to greatly increase aboveground live tree carbon in coming decades, with thinned stands accumulating aboveground live tree carbon at a slightly faster pace.

California↗

USGS2025

Optimizing the effectiveness of connectivity modifiers to reduce dryland degradation

Dryland degradation from unsustainable land use and increasing aridity often manifests as bare, interconnected areas that facilitate the loss or redistribution of resources (soil, seeds, and nutrients) through wind and run-off. Physical structures like branches and stick bundles, which disrupt these pathways and retain resources, are crucial for rehabilitation and restoration. Connectivity modifiers or ConMods, which are galvanized mesh structures that mimic low stature vegetation, are tools specifically designed to interrupt connected pathways and help reinforce overall site stability. Yet, how to effectively and consistently use ConMods to achieve site stability has not been thoroughly tested. Here, we used the Aeolian EROsion model to investigate the combined effects of ConMod height, porosity, and spacing on simulated horizontal sediment flux, a key indicator of site stability. We assessed ConMod performance as percent reduction in predicted sediment flux versus a bare, unvegetated 10,000 m 2 area for a range of horizontal sediment flux. Additionally, in a field experiment, ConMods increased litter retention by up to 15.6 mm compared to bare ground plots, demonstrating their potential to enhance both soil stabilization and resource retention. These findings underscore the potential of ConMods as flexible, cost-effective tools that interrupt positive feedbacks to degradation and provide measurable benchmarks for restoration success.

Utah↗

USGS2025

Assessment of active sand volumes at Rockaway Beach and Fire Island in New York and Seven Mile Island in New Jersey

Between 2018 and 2023, the U.S. Geological Survey assessed shoreface sediment availability at three Atlantic Coast barrier island study sites in support of a National Fish and Wildlife Foundation project entitled, “Monitoring Hurricane Sandy Beach and Marsh Resilience in New York and New Jersey.” The three study sites are Seven Mile Island, New Jersey, Rockaway Beach peninsula, New York, and Fire Island, N.Y. Previously interpreted geologic boundaries from shoreface geophysical surveys and data from repeat bathymetric surveys at each of the study sites were integrated to quantify the active sediment volume, or the volume of sediment that could contribute to beach and shoreline behavior over annual to decadal time scales. This report describes the methods used to calculate these volumes and the variability of active sediment volume for each survey at the three study sites. Our data show that when shoreface volumes account for varying alongshore extent of each study site, Seven Mile Island and Rockaway Beach peninsula have about 1.5 times the active sediment volume measured at Fire Island.

New York, New Jersey↗

USGS2025

Enhanced geothermal systems electric-resource assessment for the Great Basin, southwestern United States

The U.S. Geological Survey recently (2025) completed a provisional assessment of the geothermal-electric resources associated with high-temperature, low-permeability rock formations of the Great Basin, Southwestern United States. If sufficient technological advances to commercialize enhanced geothermal systems occur, then a current best provisional estimate for electric-power generation capacity of 135 gigawatts electric are available from the upper 6 kilometers of the Earth’s crust. This estimate is a potential substantial increase of the installed geothermal electricity-generating capacity from <1 to 10 percent of current total U.S. power production capacity.

California, Idaho, Nevada, Oregon, Utah↗

USGS2025

Using high-resolution geospatial imagery and data to document the evolution of the Wilderness Breach that was created by Hurricane Sandy in 2012 at Fire Island National Seashore, New York

The U.S. Geological Survey’s National Civil Applications Center obtained remote sensing data and imagery collected from 1939 through 2023 to monitor changes at Fire Island National Seashore, New York. On October 29, 2012, an inlet was created during Hurricane Sandy on Fire Island that remained open for 10 years. This inlet, named the “Wilderness Breach,” formed at the same location where an inlet had previously existed and remained open from 1763 to 1825. This report documents the morphological changes that occurred at the Wilderness Breach during the 10-year existence of this feature.

New York↗

USGS2025

Quality assessment of past spawning mark estimations from a long-term survey in the Connecticut River watershed

The calcified structures of fishes provide insight into their periodic growth rates and can be combined with other biological variables to identify metrics such as size or age at maturity and mortality rates. Collecting this information on growth and life history can help evaluate the success of conservation efforts and inform future management decisions for a species in need. However, before these life history data can be applied to larger stock assessments that direct management decisions, confidence in the validity of the data needs to be reported through metrics of accuracy and precision. For this report, we assessed the bias and precision of paired reader estimations of spawning marks on scales of Blueback herring (Alosa aestivalis) collected in the U.S. Fish & Wildlife (USFWS) Annual Adult River Herring Stock Assessment for the lower Connecticut River basin. The paired reads on scales from a total of 8,698 fish over the ten years of the long term monitoring program were evaluated for the annual presence of systematic bias and precision using a combination of qualitative (i.e., frequency tables) and quantitative (i.e., Evan’s and Hoenig’s Test of Symmetry, and Coefficient of Variation (CV) calculations) analyses. While seven out of the ten survey years had systematic bias detected by the tests of symmetry, only three years (2013, 2016, 2018) had imprecision values >10% CV threshold. Data were further categorized into specific age classes within survey years to increase our resolution on where bias and imprecision was most prevalent. While the ability for accurate bias detection was limited by sufficient sample sizes (>25 fish), average imprecision values increased with age, and median age classes (4 through 6) commonly had bias detected. However, the removal of insufficient age classes prior to calculating average annual CV did not significantly change the initial average. Lastly, 2023, which was the first year to implement a standardized training procedure prior to production estimating, had the highest precision for both the annual average and specific age classes compared to all prior survey years. This standardized training procedure will continue to be used by USFWS for the lower Connecticut River tributaries, and can be modified for other river systems. Overall, this report’s results highlight the importance of assessing precision and encourage the standardization of spawning mark identification quality control and assurance for future studies. With more quality assessments and baseline information on precision and bias, there can be more beneficial discussion on defining thresholds and how to implement spawning history variability into catch curve analyses.

Connecticut, Massachusetts↗

USGS2025

White‐tailed deer habitat use and implications for chronic wasting disease transmission

Animal space use, activity patterns, and habitat selection—and heterogeneity in these patterns—have important implications for where and when infectious diseases are transmitted. White-tailed deer ( Odocoileus virginianus ) are habitat generalists, with a high degree of heterogeneity in their movement ecology based on sex, age, season, and region. These heterogeneities have important implications for the transmission and management of chronic wasting disease (CWD), which is a deadly prion disease transmitted both directly and indirectly through the environment. As such, favored deer habitats may promote direct interactions between conspecifics or indirect spatial overlap and subsequent environmental transmission. However, little is known about how individual animal space use translates to actual spatial overlap between individuals, leaving uncertainty in how habitat shapes the risk of direct or environmental CWD transmission. In this study, we evaluated seasonal activity patterns, home ranges, and habitat selection for 596 white-tailed deer in southwest Wisconsin, USA, from 2017-2022. We also estimated seasonal encounter distributions—regions where a pair of deer were most likely to encounter each other—for all pairs of deer putatively in different social groups (between-group) in our study, and quantified seasonal variation in the habitat composition of these areas. We found that deer selection for crops, pasture, or grasslands was generally low, relative to forest, but was highest in the post-fawning (summer) and non-breeding (winter) seasons. We observed similar patterns for the habitat composition of encounter distributions, suggesting that crops, pasture, and grasslands may be attractive resources that facilitate between-group transmission. Site fidelity between years was generally high; combined with small female home ranges in the fawning season, this implies that females likely re-use the same small, high-quality fawning habitats from year to year. We found that attraction toward between-group individuals was low during the post-fawning season but high during the breeding (fall) and non-breeding seasons. These results suggest that space use and habitat selection could shape the risk of environmental transmission in the fawning and post-fawning seasons, social selection could favor direct transmission risk in the breeding season, and combined social and habitat selection may shape risk of both direct and environmental transmission during the non-breeding season. We provide a detailed picture of the physiological and social drivers of deer movement through the year, with implications for CWD transmission and management.

Iowa, Wisconsin↗

USGS2025

Linking fire radiative power to land cover, fire history, and environmental setting in Alaska, 2003–2022

Background Fire radiative power (FRP) shows promise as a diagnostic and predictive indicator of fire behavior and post-fire effects in Alaska, USA. Aims To investigate relationships between FRP, vegetation functional groups, and environmental settings in Alaska (2003–2022) under various fire history conditions. Methods We tested for distinctness of MODIS FRP distributions associated with vegetation classes and fire legacies (frequency and number of previous burns). We used a random forest model to examine relative importance of vegetation class for FRP versus bottom-up biophysical and temporal parameters. Key results FRP distributions are statistically distinct among vegetation functional groups with contrasting fuel biomass, or within functional groups with contrasting burn characteristics. Location and topography, which constrain vegetation class, strongly determine FRP, and fire history is of lesser importance over the 19-year analysis period. Conclusions FRP can be used to identify wildfire consumption in dissimilar vegetation classes but is highly conditioned by geographic location. The complex and evolving vegetation composition of post-fire boreal landscapes precludes a clear association of expected FRP at distinct stages of recovery. Implications These results can inform further study of FRP as an indicator of fire behavior and fuel consumption and for informing dynamics of post-fire recovery across Alaska.

Alaska↗

USGS2025

Assessment of conventional and continuous oil and gas resources in the Mowry Composite Total Petroleum System in the Southwestern Wyoming Province, Wyoming, Colorado, and Utah, 2024

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional and continuous resources of 473 million barrels of oil and 27 trillion cubic feet of gas in the Mowry Composite Total Petroleum System in the Southwestern Wyoming Province, Wyoming, Colorado, and Utah.

Colorado, Utah, Wyoming↗