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At least 343 records · Page 19Linked to original sources
USGS2014

Analysis of the impact of spatial resolution on land/water classifications using high-resolution aerial imagery

Long-term monitoring efforts often use remote sensing to track trends in habitat or landscape conditions over time. To most appropriately compare observations over time, long-term monitoring efforts strive for consistency in methods. Thus, advances and changes in technology over time can present a challenge. For instance, modern camera technology has led to an increasing availability of very high-resolution imagery (i.e. submetre and metre) and a shift from analogue to digital photography. While numerous studies have shown that image resolution can impact the accuracy of classifications, most of these studies have focused on the impacts of comparing spatial resolution changes greater than 2 m. Thus, a knowledge gap exists on the impacts of minor changes in spatial resolution (i.e. submetre to about 1.5 m) in very high-resolution aerial imagery (i.e. 2 m resolution or less). This study compared the impact of spatial resolution on land/water classifications of an area dominated by coastal marsh vegetation in Louisiana, USA, using 1:12,000 scale colour-infrared analogue aerial photography (AAP) scanned at four different dot-per-inch resolutions simulating ground sample distances (GSDs) of 0.33, 0.54, 1, and 2 m. Analysis of the impact of spatial resolution on land/water classifications was conducted by exploring various spatial aspects of the classifications including density of waterbodies and frequency distributions in waterbody sizes. This study found that a small-magnitude change (1–1.5 m) in spatial resolution had little to no impact on the amount of water classified (i.e. percentage mapped was less than 1.5%), but had a significant impact on the mapping of very small waterbodies (i.e. waterbodies ≤ 250 m 2 ). These findings should interest those using temporal image classifications derived from very high-resolution aerial photography as a component of long-term monitoring programs.

Louisiana↗
USGS2025

Assessing causes and consequences of winter surface water dynamics in California’s Central Valley using satellite remote sensing

California's Central Valley is increasingly vulnerable to winter floods. A comprehensive spatial baseline of flood extents is critical for inundation analyses that can enhance future flood predictions, but cloud cover has prevented the regular observation of surface water extents with optical satellite imagery. In this study, we leveraged the daily resolution of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data to create a continuous series of monthly Dynamic Surface Water Extent (DSWEmod) images across the Central Valley from January 2003 to January 2023. We used the timeseries to assess the climatic driving forces of winter (Oct–April) surface water variability at sub-basin and pixel scales. At the sub-basin scale, we evaluated the influences of winter precipitation, occurrence of atmospheric rivers, and antecedent soil moisture on monthly surface water extents and found that the greatest correspondence occurs in mid-winter (Dec–Feb); in contrast, non-precipitation drivers such as water management play a stronger role in autumn and spring. The pixel-level analysis identified the probabilities of precipitation-driven surface water occurrences in the Sacramento basin are highest along rivers, conveyance channels, and floodways, with higher probabilities under wetter antecedent soil moisture conditions. Precipitation-driven surface water occurrences are also common in leveed areas and outside flood boundaries designated by state and federal agencies where exposure of structures to inundation was larger in terms of their value. Finally, areas with more frequent precipitation-driven flooding have poor recharge potential but are commonly within 5 km of areas classified as having good potential. This study demonstrates a novel approach for exploring the utility of MODIS for understanding surface water dynamics in mid-winter, a period characterized by peak precipitation, flood risk, and surface water extent. This information can provide valuable insights for (1) assessing flood risks for infrastructure and populations, (2) identifying areas most suited to strategic water management investments to increase recharge, and (3) analyzing precipitation thresholds that trigger flooding to allow proactive water management strategies to minimize damage and maximize recharge.

California↗
USGS2025

Review: The hydrogeology of critical mineral resources relevant to the energy transition

Attaining the goals of the international treaty on climate change (the Paris Agreement) will greatly increase the demand for the critical minerals required to implement clean-energy technologies. This poses both challenges and opportunities to the hydrogeologic community from several perspectives. Here, important insights that the hydrogeological sciences have to offer for mineral exploration, mineral production, and addressing environmental issues related to mining and mine decommissioning are summarized. This study focuses on copper, cobalt, lithium, and rare earths to represent the broad spectrum of critical minerals and illustrate their relevance by referring to projected demands and production rates. The current understanding of the hydrogeologic processes that form major deposits of these minerals are then summarized. Ore is defined as the naturally occurring material from which minerals of economic value can be extracted, where most ore deposits are the products of complex hydrogeologic couplings between fluid flow, heat transport, solute transport, chemical reactions, and mechanical deformation. Exploration models for the discovery of deeper, hidden deposits are potentially informed by hydrogeologic theory and hydrogeochemical processes. Hydrogeologic understanding and methods are also essential to production and recovery. Longstanding challenges are mine dewatering and (conversely) mine water supply, as well as mineral-extraction practices such as spoil heap leaching and in situ mining. New challenges arise from element extraction from subsurface brines. Finally, the quantity of water use and potential environmental impacts of mining on water quality are at the core of ‘social license’: the approval and acceptance of society to mining activities.

Hydrogeology Journal↗
USGS2017

Imputation approaches for animal movement modeling

The analysis of telemetry data is common in animal ecological studies. While the collection of telemetry data for individual animals has improved dramatically, the methods to properly account for inherent uncertainties (e.g., measurement error, dependence, barriers to movement) have lagged behind. Still, many new statistical approaches have been developed to infer unknown quantities affecting animal movement or predict movement based on telemetry data. Hierarchical statistical models are useful to account for some of the aforementioned uncertainties, as well as provide population-level inference, but they often come with an increased computational burden. For certain types of statistical models, it is straightforward to provide inference if the latent true animal trajectory is known, but challenging otherwise. In these cases, approaches related to multiple imputation have been employed to account for the uncertainty associated with our knowledge of the latent trajectory. Despite the increasing use of imputation approaches for modeling animal movement, the general sensitivity and accuracy of these methods have not been explored in detail. We provide an introduction to animal movement modeling and describe how imputation approaches may be helpful for certain types of models. We also assess the performance of imputation approaches in two simulation studies. Our simulation studies suggests that inference for model parameters directly related to the location of an individual may be more accurate than inference for parameters associated with higher-order processes such as velocity or acceleration. Finally, we apply these methods to analyze a telemetry data set involving northern fur seals ( Callorhinus ursinus ) in the Bering Sea. Supplementary materials accompanying this paper appear online.

Journal of Agricultural, Biological, and Environme↗
USGS2020

Seasonal manganese transport in the hyporheic zone of a snowmelt-dominated river (East River, Colorado)

Manganese (Mn) plays a critical role in river-water quality because Mn-oxides serve as sorption sites for contaminant metals. The aim of this study is to understand the seasonal cycling of Mn in an alpine streambed that experiences large spring snowmelt events and the potential responses to changes in snowmelt timing and magnitude. To address this goal, annual variations in river-water/groundwater interaction and Mn (aq) transport were measured and modeled in the bed of East River, Colorado, USA. In observations and numerical models, oxygenated river water containing dissolved organic carbon (DOC) mixes with groundwater rich in Mn (aq) in the streambed. The mixing depth increases during spring snowmelt when river discharge increases, leading to a greater DOC supply to the hyporheic zone and net respiration of Mn-oxides, despite an enhanced supply of oxygen. As groundwater upwelling resumes during the subsequent baseflow period, Mn (aq) -rich groundwater mixes with oxygenated river water, resulting in net accumulation of Mn-oxides until the bed freezes in winter. To explore potential responses of Mn transport to different climate-induced hydrological regimes, three hydrograph scenarios were numerically modeled (historic, low-snow, and storm) for the Rocky Mountain region. In a warming climate, Mn (aq) export to the river decreases, and Mn (aq) oxidation is favored in the upper streambed sediments over more of the year. One important implication is that the streambed may have an increased sorption capacity for metals over more of the year, leading to potential changes in river-water quality.

Colorado↗
USGS2014

Volcanology: Lessons learned from Synthetic Aperture Radar imagery

Twenty years of continuous Earth observation by satellite SAR have resulted in numerous new insights into active volcanism, including a better understanding of subsurface magma storage and transport, deposition of volcanic materials on the surface, and the structure and development of volcanic edifices. This massive archive of data has resulted in fundamental leaps in our understanding of how volcanoes work – for example, identifying magma accumulation at supposedly quiescent volcanoes, even in remote areas or in the absence of ground-based data. In addition, global compilations of volcanic activity facilitate comparison of deformation behavior between different volcanic arcs and statistical evaluation of the strong link between deformation and eruption. SAR data are also increasingly used in timely hazard evaluation thanks to decreases in data latency and growth in processing and analysis techniques. The existing archive of SAR imagery is on the cusp of being enhanced by a new generation of satellite SAR missions, in addition to ground-based and airborne SAR systems, which will provide enhanced temporal and spatial resolution, broader geographic coverage, and improved availability of data to the scientific community. Now is therefore an opportune time to review the contributions of SAR imagery to volcano science, monitoring, and hazard mitigation, and to explore the future potential for SAR in volcanology. Provided that the ever-growing volume of SAR data can be managed effectively, we expect the future application of SAR data to expand from being a research tool for analyzing volcanic activity after the fact, to being a monitoring and research tool capable of imaging a wide variety of processes on different temporal and spatial scales as those processes are occurring. These data can then be used to develop new models of how volcanoes work and to improve quantitative forecasts of volcanic activity as a means of mitigating risk from future eruptions.

Journal of Volcanology and Geothermal Research↗
USGS1995

Long-term simulation of PCB export from the Fox River to Green Bay

A mass balance approach was used to model long-term PCB transport in the Fox River (Wisconsin) from Lake Winnebago to Green Bay. The objectives of this research were to (1) extend the modeling approach for the Fox River to permit realistic long-term simulations of contaminant transport and fate, (2) forecast long-term PCB export from the Fox River to Green Bay, and (3) develop a rational approach for evaluating sediment remediation alternatives. Field data collected as part of the Green Bay Mass Balance Study during 1988-90 and additional data collected by the Wisconsin Department of Natural Resources and the U.S. Geological Survey during 1992-93 were used to develop the model. A 10-year hindcast was conducted to confirm long-term model predictions. A series of 25-year forecasts were then conducted to explore the potential effects of hydrograph structure, extremely high flows, and sediment remediation on long-term PCB export from the Fox River to Green Bay. PCB export from the Fox River is forecast to decrease, and most (75%) of the PCB reservoir in Fox River sediment is expected to remain in place. However, extremely high flows in future years are forecast to cause significant PCB resuspension and export. Model forecasts suggest that long-term PCB export is only mildly sensitive to changes in hydrograph structure. Sediment remediation is forecast to reduce but not eliminate PCB export.

Wisconsin↗
USGS2023

Spatial and temporal analysis of geologic slip rates, Cucamonga Fault, California, USA: Implications for along-strike applications and multi-fault rupture

To constrain fault processes and hazard, fault slip rates may be extrapolated over different fault lengths or time intervals. Here, we investigate slip rates for the Cucamonga Fault (CF). The CF is located at the junction of the Transverse Range fault system with the San Andreas and San Jacinto Faults, and it is hypothesized to connect with these faults, promoting the propagation of large, multi-fault earthquakes. Previous work has shown that CF displacements on late Quaternary alluvial fan surfaces are highly variable along strike. We present two new 10 Be surface exposure ages from depth profiles on the alluvial fans. Slip rates are consistent with a rate of 1.4 ± 0.3 m/kyr over time intervals of ∼20, ∼30, and ∼40 kyr. If the CF participates in multi-fault ruptures, then these earthquakes occur either rarely or with sufficient regularity to maintain apparently steady rates over multiple intervals. We also explore along-strike fault displacement variability using a calibrated morphological model. The model successfully reproduces scarp profiles and indicates that fault displacement variability can be explained in part by scarp age but not uplift rate. We infer that both erosion by ephemeral gullying and distributed deformation contribute to fault displacement variability, although both are difficult to detect confidently without excavations across the scarp. These investigations show that better characterization of cumulative-slip variability along strike may improve accuracy and precision of slip rates. Slip rates that do not consider epistemic uncertainties may not be suitable for extrapolation over longer fault sections.

California↗
USGS2004

Mapping saline groundwater beneath the Sea Galilee and its vicinity using time domain electromagnetic (TDEM) geophysical technique

An extensive time domain electromagnetic (TDEM) survey covering the Sea of Galilee with a dense grid of points has been recently carried out. A total of 269 offshore and 33 supplementary onshore TDEM soundings were performed along six N-S and ten W-E profiles and at selected points both offshore and onshore along the whole coastal line. The interpreted resistivities were calibrated with the direct salinity measurements in the Haon-2 borehole and relatively deep (5 m) cores taken from the lake bottom. It was found that resistivities below 1 ohm-m are solely indicative of groundwater salinity exceeding 10,000 mg Cl/l. Such low resistivities (high salinities) were detected at depths greater than 15 m below almost the entire bottom of the lake. At some parts of the lake, particularly in the south, the saline water was detected at shallower depths, sometimes at a few meters below the bottom. Relatively high resistivity (fresh groundwater) was found along the margins of the lake down to roughly 100 m, the maximum exploration depth of the system. The detected sharp lateral contrasts at the lake margin between high and low resistivities coincide with the faults separating the carbonate and clastic units, respectively. The geometry of the fresh/saline groundwater interface below the central part of the lake is very similar to the shape of the lake bottom, probably due to the diffusive salt transport from the bottom sediments to the lake water. The above geophysical observations suggest differentsalt transport mechanisms from the sediments to the central part of the lake (diffusion) and from regional aquifers to the margins of the lake (advection). ?? 2004 Science From Israel/LPPLtd.

Israel Journal of Earth Sciences↗
USGS2017

Connecting crustal seismicity and earthquake-driven stress evolution in Southern California

Tectonic stress in the crust evolves during a seismic cycle, with slow stress accumulation over interseismic periods, episodic stress steps at the time of earthquakes, and transient stress readjustment during a postseismic period that may last months to years. Static stress transfer to surrounding faults has been well documented to alter regional seismicity rates over both short and long time scales. While static stress transfer is instantaneous and long lived, postseismic stress transfer driven by viscoelastic relaxation of the ductile lower crust and mantle leads to additional, slowly varying stress perturbations. Both processes may be tested by comparing a decade-long record of regional seismicity to predicted time-dependent seismicity rates based on a stress evolution model that includes viscoelastic stress transfer. Here we explore crustal stress evolution arising from the seismic cycle in Southern California from 1981 to 2014 using five M ≥6.5 source quakes: the M 7.3 1992 Landers, M6.5 1992 Big Bear, M 6.7 1994 Big Bear, M 7.1 1999 Hector Mine, and M 7.2 2010 El Mayor-Cucapah earthquakes. We relate the stress readjustment in the surrounding crust generated by each quake to regional seismicity using rate-and-state friction theory. Using a log likelihood approach, we quantify the potential to trigger seismicity of both static and viscoelastic stress transfer, finding that both processes have systematically shaped the spatial pattern of Southern California seismicity since 1992.

California↗
USGS2025

Timing of Steller’s Eider remigial molt has delayed over 26-year span

The Steller’s Eider is a sea duck that uses specific molting areas in lagoons in southwest Alaska, and these molting populations have declined in recent decades. The annual flight feather molt is a significant stage in avian life-history. The focus of this study was to characterize the phenology of Steller’s Eider flight feather molt timing and explore if molt timing is (1) earlier, (2) remained unchanged, or (3) is delayed. We developed a flight feather growth function throughout molt using data from captive birds. We used measurements from free-ranging birds over a 26-year period to investigate variation in molt start dates among sexes, years, and locations. Results indicate that fall molt timing has delayed over 26 years for Steller’s Eiders in our study area. We speculate that drivers of observed change in timing may be related to changes in seasonal Arctic environmental conditions. Our findings can be used by managers to inform timing of population surveys.

Alaska↗
USGS2021

Single-well production history matching and geostatistical modeling as proxy to multi-well reservoir simulation for evaluating dynamic reservoir properties of coal seams

Reservoir properties of coal seams such as gas and water effective permeabilities and gas content, as well as spatial distributions thereof, affect the success of gas production and CO 2 -enhanced gas recovery (EGR) with simultaneous CO 2 sequestration. These properties change during production and injection operations due to variations in reservoir pressure, matrix shrinkage/swelling, and water saturation and are therefore referred to as dynamic properties. Predicting distribution of such important reservoir properties and how they evolve during production, or injection, at unsampled locations can be particularly important for field development and project economics. In this work, dynamic properties of Black Creek coal seam of Black Warrior Basin, Alabama were mapped using pointwise results from single-well production history matching of 45 wells and classical geostatistics . It is explored if this approach can be a proxy, with its limitations, to multi-well reservoir simulation. For this purpose, a reservoir model was built using available reservoir, well and production data to compare its results with those of the geostatistical maps for the same properties. Despite the expected local discrepancies due to differences between the two approaches, the results showed similar patterns and global distributions. Specific results showed that despite long-time operation of the wells in this area, there were still areas with high gas content and low gas effective permeability within the modeled time interval that might have benefited from further development using additional wells.

Alabama↗
USGS2020

The influence of frost weathering on the debris flow sediment supply in an alpine basin

Rocky, alpine mountains are prone to mass wasting from debris flows. The Chalk Cliffs study area (central Colorado, USA) produces debris flows annually. These debris flows are triggered when overland flow driven by intense summer convective storms mobilizes large volumes of sediment within the channel network. Understanding the debris flow hazard in this, and similar alpine settings, requires determining the magnitude of sed- iment accumulation between debris flow seasons, and identifying the control on sediment production. To address these knowledge gaps, we measured changes in sediment produc- tion using a sediment retention fence to quantify how sedimentation was influenced by temperature at the plot scale. These measurements were extrapolated to a larger area, where we extended the sediment fence results to explore how rockfall sedimentation con- tributed to channel refilling between active debris flow periods. This work shows debris flow channel refilling is correlated with low temperatures and time in the frost-cracking window, implicating frost weathering mechanisms as a key driver of sedimentation. This sediment production process resulted in a large amount of sediment accumulation dur- ing a single winter season in our study reach (up to 0.4 m in some locations). Using these observations, we develop a channel refilling model that generally describes the mass bal- ance of debris flow watersheds in alpine areas.

Colorado↗
USGS2004

Infection experiments with Aphanomyces invadans in four species of estuarine fish

Along the eastern seaboard of the US, Atlantic menhaden, Brevoortia tyrannus, develop characteristic ulcerative lesions, a condition termed ulcerative mycosis. These lesions are identical to those seen across Asia in fish affected by epizootic ulcerative syndrome, a condition caused by the fungus-like oomycete Aphanomyces Invadans. Young-of-the-year menhaden inhabiting estuarine environments are the primary species affected in the USA and little is known about the factors involved in the initiation of the lesions, or why menhaden are predominantly infected. Atlantic menhaden, hogchoker, Trinectus maculatus, striped killifish, Fundulus majalis, and mummichog, Fundulus heteroclitus, were inoculated with A. invadans (80 zoospores per fish) to explore species differences in infection and lesion development. All four species developed lesions. Killifish developed frank lesions similar to those observed in menhaden but the gross lesions occurred later, approximately 5-10 days after those on menhaden. Hogchoker and mummichog did not develop gross skin ulcers; rather, their lesions appeared as reddened areas under the epidermis. Mummichogs also showed evidence of significant healing with a well-developed granuloma and significant myocyte regeneration. These experiments show that species barriers as well as ecological barriers can explain some of the factors involved in the development of lesions in, and specificity of the water mould for, menhaden.

Journal of Fish Diseases↗
USGS2004

Combined interpretation of radar, hydraulic, and tracer data from a fractured-rock aquifer near Mirror Lake, New Hampshire, USA

An integrated interpretation of field experimental cross-hole radar, tracer, and hydraulic data demonstrates the value of combining time-lapse geophysical monitoring with conventional hydrologic measurements for improved characterization of a fractured-rock aquifer. Time-lapse difference-attenuation radar tomography was conducted during saline tracer experiments at the US Geological Survey Fractured Rock Hydrology Research Site near Mirror Lake, Grafton County, New Hampshire, USA. The presence of electrically conductive saline tracer effectively illuminates permeable fractures or pathways for geophysical imaging. The geophysical results guide the construction of three-dimensional numerical models of ground-water flow and solute transport. In an effort to explore alternative explanations for the tracer and tomographic data, a suite of conceptual models involving heterogeneous hydraulic conductivity fields and rate-limited mass transfer are considered. Calibration data include tracer concentrations, the arrival time of peak concentration at the outlet, and steady-state hydraulic head. Results from the coupled inversion procedure suggest that much of the tracer mass migrated outside the three tomographic image planes, and that solute is likely transported by two pathways through the system. This work provides basic and site-specific insights into the control of permeability heterogeneity on ground-water flow and solute transport in fractured rock.

New Hampshire↗
USGS2004

Landsat yesterday and today: An American vision and an old challenge

Since the late 1960s, the United States government has invested more than $1 billion in designing, launching, and operating the Landsat (land satellite) series of Earth-observing satellites. Global change researchers, geologists, and environmental scientists have used images gathered by the satellites for purposes ranging from human health research, energy exploration, and pollution detection to agricultural assessments, urban growth monitoring, and earthquake lineament studies. The earliest data were captured on a digital medium called wide-band video tape (WBVT). However, two decades of unsound media storage conditions and a poorly maintained processing system have left the physically deteriorating WBVTs with no mechanism for interpretation. A national treasure was in jeopardy. With seed money from the National Aeronautics and Space Administration (NASA), the U.S. Geological Survey (USGS) began a project to rescue the data. More than 21,000 tapes from the 1970s have been transcribed to stable, archival media, preserving the data for future studies in Earth System Science.

Journal of Map & Geography Libraries↗
USGS2009

Heritage strain and diet of wild young of year and yearling lake trout in the main basin of Lake Huron

Restoration of lake trout Salvelinus namaycush stocks in Lake Huron is a fish community objective developed to promote sustainable fish communities in the lake. Between 1985 and 2004, 12.65 million lake trout were stocked into Lake Huron representing eight different genetic strains. Collections of bona fide wild fish in USGS surveys have increased in recent years and this study examined the ancestry and diet of fish collected between 2004 and 2006 to explore the ecological role they occupy in Lake Huron. Analysis of microsatellite DNA revealed that both pure strain and inter-strain hybrids were observed, and the majority of fish were classified as Seneca Lake strain or Seneca Lake hybrids. Diets of 50 wild age-0 lake trout were examined. Mysis, chironomids, and zooplankton were common prey items of wild age-0 lake trout. These results indicate that stocked fish are successfully reproducing in Lake Huron indicating a level of restoration success. However, continued changes to the benthic macroinvertebrate community, particularly declines of Mysis, may limit growth and survival of wild fish and hinder restoration efforts.

Journal of Great Lakes Research↗
USGS2013

The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1 MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO 4 -H 2 O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous sulfates likely to be found on Mars enhance our understanding of the degrees of hydration of various sulfates that should currently exist on Mars at various seasons and locations and during various atmospheric pressure and obliquity periods. Two sets of systematic experiments were described; one on hydrous Mg sulfates and the other on hydrous Fe 3+ sulfates. Also, their implications to Mars sulfates mineralogy were discussed.

Journal of Asian Earth Sciences↗