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Research about Yellowstone National Park

Source-linked reports with geographic coverage including Yellowstone National Park.

At least 37 records · Page 2Linked to original sources
USGS2022

Geophysical imaging of the Yellowstone hydrothermal plumbing system

The nature of Yellowstone National Park’s plumbing system linking deep thermal fluids to its legendary thermal features is virtually unknown. The prevailing concepts of Yellowstone hydrology and chemistry are that fluids reside in reservoirs with unknown geometries, flow laterally from distal sources and emerge at the edges of lava flows . Here we present a high-resolution synoptic view of pathways of the Yellowstone hydrothermal system derived from electrical resistivity and magnetic susceptibility models of airborne geophysical data . Groundwater and thermal fluids containing appreciable total dissolved solids significantly reduce resistivities of porous volcanic rocks and are differentiated by their resistivity signatures . Clay sequences mapped in thermal areas and boreholes typically form at depths of less than 1,000 metres over fault-controlled thermal fluid and/or gas conduits . We show that most thermal features are located above high-flux conduits along buried faults capped with clay that has low resistivity and low susceptibility. Shallow subhorizontal pathways feed groundwater into basins that mixes with thermal fluids from vertical conduits. These mixed fluids emerge at the surface, controlled by surficial permeability, and flow outwards along deeper brecciated layers. These outflows, continuing between the geyser basins, mix with local groundwater and thermal fluids to produce the observed geochemical signatures. Our high-fidelity images inform geochemical and groundwater models for hydrothermal systems worldwide.

Idaho, Wyoming↗
USGS2022

Modelling physiological costs to assess impacts of climate change on amphibians in Yellowstone National Park, U.S.A

Amphibians are vital elements of ecosystems, serving as predator and prey. Their biphasic nature makes them dependent on aquatic and terrestrial habitats; as wet-skinned ectotherms, they are vulnerable to a range of environmental threats, including climate change. Yellowstone National Park (YNP) is becoming warmer and drier, and some wetlands important to amphibians have diminished. Continued climate change is predicted to reduce snowpack, soil moisture, and forest cover. We used data from models of future climate and vegetation cover to mechanistically model how climate change might affect the movements of Western Toads ( Anaxyrus boreas ) across the landscape of three test areas in YNP for the years 2050 and 2090, compared to 2000 as a baseline. Least-cost path analysis produced mixed results: for 2050 and 2090, physiological costs of movement increased in one test area and decreased in another; they were mixed in the third. These changes generally reflect the preference by toads for more open forests. Estimating costs for other species of YNP amphibians produced more negative results. For Columbia Spotted Frogs ( Rana luteiventris ) and Boreal Chorus Frogs ( Pseudacris maculata ) (both more aquatic and less adapted to terrestrial habitats), movement costs increased by about 2–15X. Reduced frequency or duration of rain events might limit the nocturnal movements of Western Tiger Salamanders ( Ambystoma mavortium ). Climate change may not have negative impacts on all amphibians throughout YNP, but increased movement costs for terrestrial habitats will accentuate effects of drying wetlands in at least parts of YNP. Land management actions that preserve habitat structure of both forest and low shrub cover may help mitigate continued drying conditions of climate change.

Montana, Wyoming↗
USGS2022

Rub tree use and selection by American black bears and grizzly bears in northern Yellowstone National Park

Several of the world's bear species exhibit tree-rubbing behavior, which is thought to be a form of scent-marking communication. Many aspects of this behavior remain unexplored, including differences in rub tree selection between sympatric bear species. We compiled rub tree data collected on Yellowstone National Park's Northern Range (USA) and compared rub tree selection of sympatric American black bears ( Ursus americanus ) and grizzly bears ( U. arctos ) at local and landscape scales. During 2017 and 2018, we identified 217 rub trees and detected black bears at 117 rub trees and grizzly bears at 18 rub trees, based on genetic analysis of collected hair samples. Rub trees generally were located in areas with gentle slopes and close to existing animal trails. Trees selected by black bears were typically in forested areas, whereas trees selected by grizzly bears were in forested and more open areas. Use of rub trees varied seasonally and between sexes for black bears, but seasonal data were inconclusive for grizzly bears. Black bears showed preferences for certain tree species for rubbing, but we did not find evidence that rub tree selection by grizzly bears differed among tree species. Both bear species selected trees that lacked branches on the lower portions of tree trunks and the maximum rub height was consistent with the body length of the bear species that used the tree. Although the sample size for grizzly bears was small, identifying the species and sex of bears based on genetic analysis enhanced interpretation of rub tree use and selection by bears. Scent-marking by black bears and grizzly bears on similar rub objects in well-traversed areas likely serves to enhance communication within and between the 2 species.

Wyoming↗
USGS2021

Scavengers reduce potential brucellosis transmission risk in the Greater Yellowstone Ecosystem

Scavengers likely play an important role in ecosystem energy flow as well as disease transmission, but whether they facilitate or reduce disease transmission is often unknown. In the Greater Yellowstone Ecosystem, scavengers are likely to reduce the transmission and subsequent spread of brucellosis within and between livestock and elk by consuming infectious abortion materials, thereby removing the infectious agent from the landscape. We used remote cameras to monitor the time to removal of simulated abortion materials by scavengers at 264 sites from February to June in 2017 and 2018 and assessed the effects of habitat and land management on time to removal in southwest Montana. Time to removal of fetal materials decreased in grassland habitats ( x ̄ ">

Wyoming↗
USGS2021

Physiological consequences of consuming low-energy foods: Herbivory coincides with a stress response in Yellowstone bears.

Meat, fruit, seeds and other high-energy bear foods are often highly localized and briefly available and understanding which factors influence bear consumption of these foods is a common focus of bear conservation and ecology. However, the most common bear foods, graminoids and forbs, are more widespread but of lower quality. We poorly understand how herbage consumption impacts bear physiology, such as endocrine system function that regulates homeostasis and stress responses. Here, we described bear diets with a novel approach, measuring the concentration of chlorophyll in bear scats (faecal chlorophyll) to index the proportion of the recent diet that was composed of leaves from graminoids and forbs. We measured faecal chlorophyll and faecal cortisol in 351 grizzly ( Ursus arctos , n = 255) and black bear ( Ursus americanus , n = 96) scats from Yellowstone National Park in 2008–2009. We compared models of faecal chlorophyll and faecal cortisol concentrations considering the effects of spatial, dietary, scat and bear-specific factors including species. Faecal chlorophyll levels were the strongest predictor of faecal cortisol in a manner that suggested an endocrine response to a low-energy diet. Both compounds were highest during the spring and early summer months, overlapping the breeding season when higher energy foods were less available. Effects of scat composition, scat weathering, bear age, bear sex, species and other factors that have previously been shown to influence faecal cortisol in bears were not important unless faecal chlorophyll was excluded from models. The top models of faecal chlorophyll suggested grazing was primarily influenced by spatial attributes, with greater grazing closer to recreational trails, implying that elevated cortisol with grazing could be a response to anthropogenic activity. Our results confirm that higher stress hormone concentrations correspond with lower quality diets in bears, particularly grazing, and that faecal chlorophyll shows promise as a metric for studying grazing behaviour and its consequences.

Wyoming↗
USGS2021

Elk migration influences the risk of disease spillover in the Greater Yellowstone Ecosystem

Wildlife migrations provide important ecosystem services, but they are declining. Within the Greater Yellowstone Ecosystem (GYE) some elk ( Cervus canadensis ) herds are losing migratory tendencies, which may increase spatiotemporal overlap between elk and livestock (domestic bison [ Bison bison ] and cattle [ Bos taurus ]), potentially exacerbating pathogen transmission risk. We combined disease, movement, demographic, and environmental data from eight elk herds in the GYE to examine the differential risk of brucellosis transmission (through aborted fetuses) from migrant and resident elk to livestock. For both migrants and residents, we found that transmission risk from elk to livestock occurred almost exclusively on private ranchlands as opposed to state or federal grazing allotments. Weather variability affected the estimated distribution of spillover risk from migrant elk to livestock, with a 7‐12% increase in migrant abortions on private ranchlands during years with heavier snowfall. In contrast, weather variability did not affect spillover risk from resident elk. Migrant elk were responsible for the majority (68%) of disease spillover risk to livestock because they occurred in greater numbers than resident elk. On a per‐capita basis, however, our analyses suggested that resident elk disproportionately contributed to spillover risk. In five of seven herds, we estimated that the per‐capita spillover risk was greater from residents than from migrants. Averaged across herds, an individual resident elk was 23% more likely than an individual migrant elk to abort on private ranchlands. Our results demonstrate links between migration behavior, spillover risk, and environmental variability, and highlight the utility of integrating models of pathogen transmission and host movement to generate new insights about the role of migration in disease spillover risk. Further, they add to the accumulating body of evidence across taxa that suggests that migrants and residents should be considered separately during investigations of wildlife disease ecology. Finally, our findings have applied implications for elk and brucellosis in the GYE, and suggest that managers should prioritize actions that maintain spatial separation of elk and livestock on private ranchlands during years when snowpack persists into the risk period.

Wyoming↗
USGS2021

Yellowstone Volcano Observatory 2019 annual report

The Yellowstone Volcano Observatory (YVO) monitors volcanic and hydrothermal activity associated with the Yellowstone magmatic system, conducts research into magmatic processes occurring beneath Yellowstone Caldera, and issues timely warnings and guidance related to potential future geologic hazards. This report summarizes the activities and findings of YVO during the year 2019, focusing on the Yellowstone volcanic system. Highlights of YVO research and related activities during 2019 included deploying a portable seismic array near Steamboat Geyser in Norris Geyser Basin that recorded signals from seven major water eruptions; deploying a semipermanent Global Positioning System array; surveying soil carbon dioxide flux and temperature and operating an eddy covariance system to make continuous measurements; collecting and analyzing water samples from Shoshone Geyser Basin, the outlets of Shoshone and Lewis Lakes, Cinder Pool in Norris Geyser Basin, and several locations along Obsidian Creek; exploring and documenting a new thermal area near Tern Lake that was discovered in 2018; measuring specific conductance along major rivers to determine the chloride flux and total heat output of the Yellowstone hydrothermal system; conducting an inventory of hydrothermal features in Norris Geyser Basin and Upper Geyser Basin as part of a park-wide project that began in 2018; and sampling of tree rings and silica sinter deposits in the Upper Geyser Basin to better understand hydrothermal activity over time. Continuing the pattern that started in 2018, Steamboat Geyser, in Norris Geyser Basin, erupted 48 times in 2019—a new record for a calendar year! Overall, however, noteworthy geyser activity in Yellowstone National Park was much reduced relative to the previous year. Thermal features on Geyser Hill in the Upper Geyser Basin had returned to their normal activity styles after Ear Spring’s September 2018 eruption and did not show any significant changes in 2019. Giant Geyser, also in the Upper Geyser Basin, did not experience any eruptions after March 2019. Seismicity was reduced relative to previous years, and deformation of Norris Geyser Basin, which started as uplift in 2015 and paused in late 2018, shifted to subsidence in late 2019. Overall subsidence of the caldera floor, ongoing since late 2015 or early 2016, continued at rates of a few centimeters (1–2 inches) per year.

Wyoming↗
USGS2021

Yellowstone Volcano Observatory 2018 annual report

The Yellowstone Volcano Observatory (YVO) monitors volcanic and hydrothermal activity associated with the Yellowstone magmatic system, conducts research into magmatic processes occurring beneath Yellowstone Caldera, and issues timely warnings and guidance related to potential future geologic hazards. This report summarizes the activities and findings of YVO during the year 2018, focusing on the Yellowstone magmatic system. The most noteworthy seismic activity of the year was a February swarm of hundreds of earthquakes in the same area as the 2017 Maple Creek earthquake swarm. The February 2018 activity is viewed as a continuation of the 2017 swarm. Ground deformation trends were mostly unchanged throughout the year, with uplift of the Norris Geyser Basin area and subsidence of the caldera. Field work in 2018, conducted under research permits granted by the National Park Service, included routine maintenance visits to seismic and geodetic stations as well as deployment of a semipermanent Global Positioning System network during the summer months; installation of an eddy covariance system for tracking carbon dioxide emissions and heat flux near Norris Geyser Basin; deployment of nodal seismic arrays on Geyser Hill, near Steamboat Geyser, and around Yellowstone Lake; and collection of water and gas samples from the Bechler River area in the southwest part of Yellowstone National Park. In addition, examination of satellite thermal imagery resulted in the discovery of a new thermal area on the east side of the Sour Creek resurgent dome, near west Tern Lake. This thermal area appears to have started forming in the early 2000s; before then it was an area of healthy forest. The year might best be remembered, however, for some extraordinary geyser and hot spring activity, specifically at Steamboat Geyser and Ear Spring.

Wyoming↗
USGS2021

Thermal constraints on energy balance, behaviour and spatial distribution of grizzly bears

1. Heat dissipation limit theory posits that energy available for growth and reproduction in endotherms is limited by their ability to dissipate heat. In mammals, endogenous heat production increases markedly during gestation and lactation, and thus female mammals may be subject to greater thermal constraints on energy expenditure than males. Such constraints likely have important implications for behaviour and population performance in a warming climate. 2. We used a mechanistic simulation model based on the first principles of heat and mass transfer to study thermal constraints on activity (both timing and intensity) of captive female grizzly bears Ursus arctos in current and future climate scenarios. We then quantified the relative importance of regulatory behaviours for maintaining heat balance using GPS telemetry locations of lactating versus non-lactating female bears from Yellowstone National Park, and assessed the degree to which costs of thermoregulation constrained the distribution of sampled bears in space and time. 3. Lactating female bears benefitted considerably more from behavioural cooling mechanisms (e.g. partial submersion in cool water or bedding on cool substrate) than non-lactating females in our simulations; the availability of water for thermoregulation increased the number of hours during which lactating females could be active by up to 60% under current climatic conditions and by up to 43% in the future climate scenario. Moreover, even in the future climate scenario, lactating bears were able to achieve heat balance 24 hr/day by thermoregulating behaviourally when water was available to facilitate cooling. 4. The most important predictor of female grizzly bear distribution in Yellowstone, regardless of reproductive status, was elevation. However, variables associated with the thermal environment were relatively more important for predicting the distribution of lactating than non-lactating female bears. 5. Our results suggest that the costs of heat dissipation, which are modulated by climate, may impose constraints on the behaviour and energetics of large endotherms like grizzly bears, and that access to water for cooling will likely be an increasingly important driver of grizzly bear distribution in Yellowstone as the climate continues to warm.

Wyoming↗
USGS2021

The structure and volume of large geysers in Yellowstone National Park, USA and the mineralogy and chemistry of their silica sinter deposits

Siliceous sinter is formed by biogenic and abiogenic opal deposition around hot springs and geysers. Using Structure-from-Motion photogrammetry we generated three-dimensional models of Giant and Castle Geysers from the Upper Geyser Basin of Yellowstone National Park. We use these models to calculate an approximate mass of sinter for each (~2 and ~ 5 kton, respectively) and estimate a range of plausible long-term deposition rates for Castle Geyser (470 to 940 kg·yr −1 ). We estimate ~2% of the silica discharged from Castle Geyser is deposited as sinter in the cone and proximal terraces. We collected 15 sinter samples following the stratigraphy of each geyser from an older terrace to a younger cone and examined them using a variety of analytical methods. We find that young opaline sinter with a water content of <12 wt% (from loss on ignition) contains higher concentrations of major and trace elements, notably As, Sb, Rb, Ga and Cs, relative to older dehydrated sinter. Rare earth element (REE) concentrations in sinter are 2–3 orders of magnitude higher than in the thermal water from which they are deposited. Sinter deposits are enriched in light REE, Gd and Yb when normalized to concentrations in thermal water and enriched in Eu, Tm, and Yb when normalized to the underlying rhyolite. Sinter samples with the highest REE concentrations are also enriched in organic material, implying either microbial uptake of REE, or that organic molecules are efficient ligands that form metal complexes.

Wyoming↗
USGS2021

Multiscale hyperspectral imaging of hydrothermal alteration in Yellowstone National Park, USA

Imaging spectroscopy (hyperspectral imaging) data have mainly been used to map surface materials covering relatively small areas from airborne sensors over the past 20+ years. As part of the U.S. Geological Survey Integrated hyperspectral, geophysical and geochemical studies of Yellowstone National Park hydrothermal systems project, we have collected multiscale imaging spectrometer data including borehole core, field, and airborne data. These data give us the unique opportunity to map subsurface and surface alteration of shallow epithermal systems at scales ranging from microns to meters per pixel. Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), Corescan HCI-3, HySpex VNIR-1800 and SWIR-384 imaging spectrometers, and a Riegl VZ-2000i terrestrial lidar system were used in this study. Maps utilizing spectral analysis of multiscale hyperspectral data indicate the presence of mineral assemblages consistent with epithermal deposits. Minerals such as alunite, hydrated silica, and kaolinite typically form in steam-heated cap systems and can be found in core and AVIRIS data. At depth, higher temperature fluids that are less acidic produce mixed-layer kaolinite with clay/muscovite and then montmorillonite and muscovite towards the bottom of the borehole. This transition can be seen in AVIRIS and field data at the Grand Canyon of the Yellowstone and in borehole Corescan data at Y-12 Norris-Ii R874. Instrument specifications, collection parameters, and setup for data acquisition will be discussed as well as mapping software and preliminary results.

Idaho, Montana, Wyoming↗
USGS2021

Acoustic interaction between a pair of owls and a wolf

During summer 2019, we recorded an apparent vocal interaction, lasting just under 4 min, between a pair of Great Horned Owls ( Bubo virginianus ) and a gray wolf ( Canis lupus ) in Yellowstone National Park. To our knowledge, this is the first report of such an acoustic interaction in the scientific literature. The increased use of passive acoustic recorders, which record spontaneous vocalizations emitted by animals over long periods, will allow us to better document and study the importance of such interspecific interactions.

Wyoming↗
USGS2020

Yellowstone's Old Faithful Geyser shut down by a severe 13th century drought

To characterize eruption activity of the iconic Old Faithful Geyser in Yellowstone National Park over past centuries, we obtained 41 new radiocarbon dates of mineralized wood preserved in the mound of silica that precipitated from erupted waters. Trees do not grow on active geyser mounds, implying that trees grew on the Old Faithful Geyser mound during a protracted period of eruption quiescence. Rooted stumps and root crowns located on higher parts of the mound are evidence that at the time of tree growth, the geyser mound closely resembled its current appearance. The range of calibrated radiocarbon dates (1233–1362 CE) is coincident with a series of severe multidecadal regional droughts toward the end of the Medieval Climate Anomaly, prior to the onset of the Little Ice Age. Climate models project increasingly severe droughts by mid‐21st century, suggesting that geyser eruptions could become less frequent or completely cease.

Wyoming↗
USGS2020

Hydrothermal activity in the southwest Yellowstone Plateau Volcanic Field

In the past two decades, the U.S. Geological Survey and the National Park Service have studied hydrothermal activity across the Yellowstone Plateau Volcanic Field (YPVF) to improve the understanding of the magmatic-hydrothermal system and to provide a baseline for detecting future anomalous activity. In 2017 and 2018 we sampled water and gas over a large area in the southwest YPVF and used Landsat 8 thermal infrared data to estimate radiative heat flow. Most of the thermal activity in this region is in close proximity to the Yellowstone Caldera boundary. Springs and fumaroles discharge from a variety of lithologies including some of the youngest rhyolites in the YPVF. Gas compositions and helium isotope ratios of most samples resemble those in other parts of the YPVF. The waters have meteoric origins and tritium was detected in several samples. Thermal waters from some areas have compositions that plot along a line connecting thermal and non-thermal water endmember compositions. The thermal water endmember equilibrated at 160-170 °C, lower than waters in Yellowstone’s geyser basins. Heat discharged by springs and fumaroles originates from within the Yellowstone Caldera and is transported laterally by advection, mainly along the base of rhyolite flows that cover the inferred caldera boundaries.

Yellowstone National Park↗
USGS2020

A newly emerging thermal area in Yellowstone

Yellowstone is a large restless caldera that contains many dynamic thermal areas that are the surface expression of the deeper magmatic system. In 2018, using a Landsat 8 nighttime thermal infrared image, we discovered the emergence of a new thermal area located near Tern Lake on the northeast margin of the Sour Creek dome. A high-spatial-resolution airborne visible image from August 2017 revealed a large (~33,000 m2) area of recently fallen trees, mostly devoid of vegetation, with bright soil, similar to other nearby thermal areas. Field observations in August 2019 confirmed that this was a steam-heated acid-sulfate thermal area, with an arc-shaped zone of hydrothermally altered soil and heated ground, with surface temperatures of 60-80 °C, several steaming fumaroles, and boiling temperatures (93 °C) just beneath the surface. Fallen trees in contact with warm ground were being carbonized, yet there were some cooler areas with new trees growing. Observations of stressed or dying vegetation from archived satellite and airborne remote sensing data going back to 1994 indicated that this thermal area started emerging around 2000. It increased in size slowly until around 2005, when the radiative heat output started measurably increasing. From 2005 to 2012 it grew more rapidly; and from 2012 through 2019 the growth rate slowed and the heat output stabilized. We predict that this stabilizing trend will continue in the coming years. The initial formation of this new thermal area was not clearly linked to any distinct seismic or geodetic events, although the period of rapid growth partly coincided with a period of rapid local uplift, possibly suggesting a causative relationship. The identification of this emerging thermal area illustrates the importance of satellite thermal infrared imaging combined with high-spatial-resolution remote sensing data and field observations for mapping, measuring, and monitoring Yellowstone's thermal areas. It is also an example of the dynamics we expect to observe within large caldera systems like Yellowstone, where changes in the size and distribution of thermal areas are normal and do not indicate an impending eruption nor any significant changes in the broader magmatic system.

Wyoming↗
USGS2020

Magma intrusion and volatile ascent beneath Norris Geyser Basin, Yellowstone National Park

Recent activity has provided new insights into the causes of surface deformation in and around the Yellowstone Caldera, a topic that has been debated since the discovery of caldera floor uplift more than four decades ago. An episode of unusually rapid uplift (>15 cm/yr) centered near Norris Geyser Basin along the north caldera rim began in late 2013 and continued until a M w 4.9 earthquake on 30 March 2014; thereafter, uplift abruptly switched to subsidence. Uplift at rates of several centimeters per year resumed in 2016 and continued at least through the end of 2018. Modeling of Global Positioning System and interferometric synthetic aperture radar data suggests an evolving process of deep magma intrusion during 1996–2001 followed by volatile ascent and accumulation at shallow levels, perhaps as shallow as a few hundred meters depth. The depth of shallow volatile accumulation appears to have shallowed from the 2014 to the 2016 deformation episode, and frequent eruptions of Steamboat Geyser since March 2018 are likely a surface manifestation of this ongoing process. Hydrothermal explosion features are prominent in the Norris Geyser Basin area, and the apparent shallow nature of the volatile accumulation implies an increased risk of hydrothermal explosions.

Wyoming↗