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All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Modeling lunar volcanic eruptions

Simple physical arguments are used to show that basaltic volcanos on different planetary bodies would fountain to the same height if the mole fraction of gas in the magma scaled with the acceleration of gravity. It is suggested that the actual eruption velocities and fountain heights are controlled by the velocities of sound in the two phase gas/liquid flows. These velocities are in turn determined by the gas contents in the magma. Predicted characteristics of Hawaiian volcanos are in excellent accord with observations. Assuming that the only gas in lunar volcano is the CO which would be produced if the observed Fe metal in lunar basalts resulted from graphite reduction, lunar volcanos would fountain vigorously, but not as spectacularly as their terrestrial counterparts. The volatile trace metals, halogens, and sulfur released would be transported over the entire moon by the transient atmosphere. Orange and black glass type pyroclastic materials would be transported in sufficient amounts to produce the observed dark mantle deposits.

Housley, R. M.↗
NASA NTRS1979

The structure and emplacement of cinder cone fields

The paper examines the structure and emplacement of cinder cone fields. Terrestrial cinder cone fields occur in volcanic provinces upon the flanks of major volcanoes or within relatively flat-lying volcanic fields. Measurements of cone shape and distribution were made in three volcano cone fields and three platform cone fields, and it was found that modal average values of cone basal diameter are on the order of 300 to 400 m within volcano cone fields and 900 to 1000 m within platform cone fields. The average morphometric parameters for the six fields indicate that cone diameter is positively correlated with cone separation distance, and that the size and spacing of cinder cones formed on the flanks of volcanoes is less than the size and spacing of cones constructed in volcanic fields.

Settle, M.↗
NASA NTRS1985

Topographic Evidence for Shield Volcanism on Io

A volcano was identified whose morphology, especially topography, supports and extends current evidence that shield volcanoes occur on Io. The feature is centered at 30 deg. S, 246 deg w and lies in a region near the terminator. The presence of shield volcanism on Io was inferred from the planimetric configuration of flaws on such features as Ra Patera. A central edifice roughly 40 to 50 km in diameter is situated on intervent plains material, and a broad, slightly elliptical base 75 to 90 km across. The size of this feature is comparable to large shield volcanoes found on Earth. In addition, the topography is similar to some terrestrial shield volcanoes that exhibit a change in slope; the steepening may be explained by shorter and/or thicker flows emplaced during late stage eruptions.

Albin, E. F.↗
NASA NTRS1987

Small Martian valcanoes

Various types of volcanoes were identified on Mars, mainly on the basis of qualitative morphologic criteria such as relief, circularity, summit craters, and alignment with structural trends. A survey of Viking Orbiter images is being conducted to identify possible candidates for Martian volcanoes. The topographic profiles of the selected Martian volcanoes that are currently being acquired will be compared with tabulated data for terrestrial and lunar volcanoes. Variation in volcanic style with age will also be examined.

Davis, Philip A.↗
NASA NTRS1988

Polygenic eruptions on Alba Patera, Mars

A new model for the evolution of the martian volcano Alba Patera is constructed. Numerous digitate channel networks on the flanks of the volcano are interpreted to be carved by sapping due to the release of nonjuvenile water from unconsolidated flank deposits. The particle size of these deposits is estimated to be 3-10 microns, which, together with theoretical modelling of the disperison of explosively derived volcanic materials, leads to the conclusion that the flank deposits on Alba Patera are low-relief pyroclastic flows. The recognition of numerous late-stage summit and subterminal lava flows thus makes Alba Patera a unique martian volcano that is transitional between the older pyroclastic-dominated highland paterae and the more recent effusive central-vent volcanoes such as the Tharsis Montes.

Mouginis-Mark, P. J.↗
NASA NTRS1991

Volcanic effects on climate

Volcanic eruptions which inject large amounts of sulfur-rich gas into the stratosphere produce dust veils which last years and cool the earth's surface. At the same time, these dust veils absorb enough solar radiation to warm the stratosphere. Since these temperature changes at the earth's surface and in the stratosphere are both in the opposite direction of hypothesized effects from greenhouse gases, they act to delay and mask the detection of greenhouse effects on the climate system. Tantalizing recent research results have suggested regional effects of volcanic eruptions, including effects on El Nino/Southern Oscillation (ENSO). In addition, a large portion of the global climate change of the past 100 years may be due to the effects of volcanoes, but a definite answer is not yet clear. While effects of several years were demonstrated with both data studies and numerical models, long-term effects, while found in climate model calculations, await confirmation with more realistic models. Extremely large explosive prehistoric eruptions may have produced severe weather and climate effects, sometimes called a 'volcanic winter'. Complete understanding of the above effects of volcanoes is hampered by inadequacies of data sets on volcanic dust veils and on climate change. Space observations can play an increasingly important role in an observing program in the future. The effects of volcanoes are not adequately separated from ENSO events, and climate modeling of the effects of volcanoes is in its infancy. Specific suggestions are made for future work to improve the knowledge of this important component of the climate system.

Robock, Alan↗
NASA NTRS1992

Venus volcanism: A global overview from Magellan data

A preliminary analysis of a global survey of Magellan data covering over 90 percent of the surface and designed to document the characteristics, location, and dimensions of all major volcanic features on Venus has revealed over 1660 landforms and deposits. These include over 550 shield fields (concentrations of small volcanos less than 20 km in diameter), 274 intermediate volcanos between 20 and 100 km diameter with a variety of morphologies, 156 large volcanos in excess of 100 km diameter, 86 calderalike structures independent of those associated with shield volcanos and typically 60-80 km in diameter, 175 coronae (annulus of concentric ridges or fractures), 259 arachnoids (inner concentric and outer radial network pattern of fractures and ridges), 50 novae (focused radial fractures forming stellate patterns), and 53 lava flood-type flow fields, and 50 sinuous lava channels (all of which are in excess of 10(exp 2)-10(exp 3) km in length). The near-global coverage of Magellan data analyzed in this study confirms and extends the results of earlier observations that showed that volcanism is a widespread and significant process on the surface of Venus for the period of time in the presently observed record (less than about the last one billion years).

Head, James W., III↗
NASA NTRS2002

Effects of Volcanic Eruptions on Stratospheric Ozone Recovery

The effects of the stratospheric sulfate aerosol layer associated with the Mt. Pinatubo volcano and future volcanic eruptions on the recovery of the ozone layer is studied with an interactive two-dimensional photochemical model. The time varying chlorine loading and the stratospheric cooling due to increasing carbon dioxide have been taken into account. The computed ozone and temperature changes associated with the Mt. Pinatubo eruption in 1991 agree well with observations. Long model runs out to the year 2050 have been carried out, in which volcanoes having the characteristics of the Mount Pinatubo volcano were erupted in the model at 10-year intervals starting in the year 2010. Compared to a non-volcanic run using background aerosol loading, transient reductions of globally averaged column ozone of 2-3 percent were computed as a result of each of these eruptions, with the ozone recovering to that computed for the non-volcanic case in about 5 years after the eruption. Computed springtime Arctic column ozone losses of from 10 to 18 percent also recovered to the non-volcanic case within 5 years. These results suggest that the long-term recovery of ozone would not be strongly affected by infrequent volcanic eruptions with a sulfur loading approximating Mt. Pinatubo. Sensitivity studies in which the Arctic lower stratosphere was forced to be 4 K and 10 K colder resulted in transient ozone losses of which also recovered to the non-volcanic case in 5 years. A case in which a volcano five times Mt. Pinatubo was erupted in the year 2010 led to maximum springtime column ozone losses of 45 percent which took 10 years to recover to the background case. Finally, in order to simulate a situation in which frequent smaller volcanic eruptions result in increasing the background sulfate loading, a simulation was made in which the background aerosol was increased by 10 percent per year. This resulted in a delay of the recovery of column ozone to 1980 values of more than 10 years.

Rosenfield, Joan E.↗
NASA NTRS2005

Discrete element simulations of gravitational volcanic deformation: Deformation structures and geometries - 1

We have carried out two-dimensional particle dynamics simulations of granular piles subject to frictional Coulomb failure criteria to gain a first-order understanding of different modes of gravitational deformation within volcanoes. Under uniform basal and internal strength conditions, granular piles grow self-similarly, developing distinctive stratigraphies, morphologies, and structures. Piles constructed upon cohesive substrates exhibit particle avalanching, forming outward dipping strata and angle of repose slopes. Systematic decreases in basal strength lead to progressively deeper and steeper internal detachment faults and slip along a basal decollement; landslide forms grade from shallow slumps to deep-seated landslide and, finally, to axial subsidence and outward flank displacements, or volcanic spreading. Surface slopes decrease and develop concave up morphologies with decreasing decollement strength; depositional layers tilt progressively inward. Spatial variations in basal strength cause lateral transitions in pile structure, stratigraphy, and morphology. This approximation of volcanoes as Coulomb granular piles reproduces the richness of deformational structures and surface morphologies in many volcanic settings. The gentle slopes of Hawaiian volcanoes and Olympus Mons on Mars suggest weak basal decollements that enable volcanic spreading. High-angle normal faults, favored above weak decollements, are interpreted in both settings and may explain catastrophic sector collapse in Hawaii and broad aureole deposits surrounding Olympus Mons. In contrast, steeper slopes and shallow detachment faults predominate in the Canary Islands, thought to lack a weak decollement, favoring smaller, more frequent slope failures than predicted for Hawaii. The numerical results provide a useful predictive tool for interpreting dynamic behavior and associated geologic hazards of active volcanoes.

Morgan, Julia K.↗
NASA NTRS2008

Geologic Mapping of the Zal, Hi'iaka, and Shamshu Regions of Io

We have produced regional geologic maps of the Zal, Hi'iaka, and Shamshu regions of Io s antijovian hemisphere based on Galileo mission data. Here we discuss the geologic features, summarize the map units and structures that are present, discuss the nature of volcanic activity, and give an analysis of the volcanic, tectonic, and gradational processes that affect the regions in order to better understand Io s geologic evolution. Zal Region: The Zal region (25-45degN, 65-85degW) consists of Zal Patera (120 km wide x 197 km long), two major mountains (north and south Zal Montes) which border Zal Patera to the west and south [1], and an unnamed patera ("Patera A") west of south Zal Montes. The Zal region includes at least two hotspots detected by Galileo: one along the western scarp of the Zal Patera volcano and one at the "Patera A" volcano. The floor of Zal Patera has been partly resurfaced by dark lava flows since Voyager imaging; portions of the patera floor appear unchanged during the Galileo mission. Mountains exhibit stages of degradation. The western bounding scarp of Zal Patera appears to be a fissure source vent for multiple silicate lava flows. The Zal Montes and Patera complex appears to be an example of volcano-tectonic interactions [1, 2]. Several of the flow units emanate from the fissure at the western scarp [2]. Hi'iaka Region: The Hi'iaka region (approx.12degS-5degN, 75-87degW) consists of Hi'iaka Patera, a large (60 km wide x 95 km long) patera, north and south Hi iaka Montes which border Hi'iaka Patera to the west and south and are L-shaped mirror-images of each other, west Hi'iaka Montes, a small isolated peak, and an unnamed patera ("Patera B") located south of north Hi'iaka Montes. The region includes one hotspot at Hi'iaka Patera. The floor of the patera exhibits flow deposits of differing ages. The eastern scarp of Hi'iaka Patera may be a fissure source vent for the patera floor materials. The Hi iaka Montes and Patera complex appears to be an example of volcano-tectonic interactions [1, 2]. Shamshu Region: The Shamshu region (approx.15degS-5degS, 55-77degW) consists of Shamshu Patera, three mountain units (west, north, and south Shamshu Mons), and a small unnamed patera ("Patera C") southwest of Shamshu Mons.

Bunte, Melissa K.↗
NASA NTRS2015

Volcanism on Mars

Spacecraft exploration has revealed abundant evidence that Mars possesses some of the most dramatic volcanic landforms found anywhere within the solar system. How did a planet half the size of Earth produce volcanoes like Olympus Mons, which is several times the size of the largest volcanoes on Earth? This question is an example of the kinds of issues currently being investigated as part of the space-age scientific endeavor called "comparative planetology." This chapter summarizes the basic information currently known about volcanism on Mars. The volcanoes on Mars appear to be broadly similar in overall morphology (although, often quite different in scale) to volcanic features on Earth, which suggests that Martian eruptive processes are not significantly different from the volcanic styles and processes on Earth. Martian volcanoes are found on terrains of different age, and Martian volcanic rocks are estimated to comprise more than 50% of the Martian surface. This is in contrast to volcanism on smaller bodies such as Earth's Moon, where volcanic activity was mainly confined to the first half of lunar history (see "Volcanism on the Moon"). Comparative planetology supports the concept that volcanism is the primary mechanism for a planetary body to get rid of its internal heat; smaller bodies tend to lose their internal heat more rapidly than larger bodies (although, Jupiter's moon Io appears to contradict this trend; Io's intense volcanic activity is powered by unique gravitational tidal forces within the Jovian system; see "Volcanism on Io"), so that volcanic activity on Mars would be expected to differ considerably from that found on Earth and the Moon.

Mars↗
NASA NTRSDate not supplied

Detecting Volcanic Co2 Emissions Hidden in Tropical Volcanic Forests Using Fixed-Wing sUAS

CO2 emissions are among the earliest indicators of subsurface state change and reactivation of volcanic systems and these deep signals reflect in faint diffuse emissions variations on volcanic flanks. Monitoring vast areas of rainforests covering tropical volcanoes is challenging, and space-borne sensors like OCO-2 are not sensitive enough. Fortunately, trees exposed to mild enhancements of CO2 may experience fertilization and build excess CO2 into excess biomass (Cawse-Nicholson, et al. 2018, Biogeosciences). They also process excess CO2 through photosynthesis, measurable by fluorescence (Bogue et al., 2019, Biogeosciences). Furthermore, spaceborne remote sensing instruments have demonstrated increasing NDVI months to years before eruptions, unexplained by other factors (e.g., Houlie et al. 2006, EPSL; Seiler et al. 2017, PLoS One). By providing a means to map large areas of above-canopy CO2 variations over tropical rainforest on the flanks of actively degassing volcanoes, we enable to interpret the signals plants provide in response to excess CO2 with airborne and spaceborne hyperspectral remote sensing methods, including a possible future Surface Biology and Geology (SBG) NASA satellite mission.As a critical step to mature and test this concept, we deployed small unmanned aerial systems (sUAS) using a fixed-wing sUAS designed for autonomous operations and long endurance in extreme environments, without causing significant disturbance of the sampled air. We integrated an in-situ sensor to record the CO2 enhancement field above the forest canopy. Test flight results on the flanks of Turrialba volcano in Costa Rica above forest canopies covering known moderate gas seeps demonstrate the sUAS-borne detection and mapping capabilities of above-canopy elevated CO2 gradients. The strong detection capabilities and high detector signal stability resulted from key system design elements including RF shielding, mechanical stabilization, and calibration procedures. This highly robust system is readily applied for diffuse volcanic CO2 emission studies on active volcanoes covered by dense vegetation.

Volcanic↗
NASA NTRSDate not supplied

The Project “Analogs for VENus’s GEologically Recent Surfaces” (AVENGERS): Unveiling Active Volcanism on Venus

The recently selected missions to Venus opened a new era for the exploration of the Earth’s hellish twin sister. One of the key questions that the selected missions to Venus will address is whether the planet is volcanically active. The identification of ongoing volcanic activity on Venus can indeed unveil important clues on the geologic evolution of the planet, also helping us to better understand how volcanic and atmospheric processes work on Earth, especially those related to the climate change produced by greenhouse gases. To fully contextualize the higher resolution datasets to be provided by the future missions to Venus, we need to be able to exploit the wealth of data to be produced in the best possible way. Different types of instruments will indeed perform unprecedent orbiting and in-situ investigations of the surface and subsurface of Venus. To this regard, the Project “Analogs for VENus’s GEologically Recent Surfaces” (AVENGERS) aims to build a comprehensive database of Terrestrial active volcanoes which may act as suitable analogs for identifying ongoing volcanic activity on Venus. To do this, the project AVENGERS will combine the implementation of terrestrial orbiter radar data analysis techniques (i.e., radar interferometry) with infrared and laboratory analyses of lava flow samples from Terrestrial active volcanoes. As a first suitable analog of the Project AVENGERS, we selected Mount Etna in Sicily for a direct comparison with potentially active volcanic structures of Venus, and with Idunn Mons, one of the most promising possibly active volcanoes of Venus. Given its composite nature, Mount Etna offers the opportunity to identify and study multiple types of eruptive products (both effusive and explosive) from the analysis of high-resolution radar images. The frequent eruptions characterizing this volcano will also allow to test techniques of radar interferometry. Moreover, its ease of access facilitates geologic field trips and in-situ investigations with related sample retrieving. Ongoing infrared laboratory analysis on several altered and unaltered samples retrieved by Mount Etna will help to distinguish spectral signatures of fresh vs weathered volcanic deposits.

P. D’Incecco↗
DOE OSTI2020

Play Fairway analysis of geothermal resources across the State of Hawai‘i: 4. Updates with new groundwater chemistry, subsurface stress analysis, and focused geophysical surveys

This paper is the fourth in a series on a play fairway analysis of geothermal resources across the State of Hawai‘i. Here we describe recent exploration activities that include groundwater sampling in ten locations statewide, as well as geophysical surveys on Lana‘i, across the SW rift of Haleakala Volcano (Maui), and surrounding Mauna Kea Volcano (Hawai‘i Island). We derive a first-order method for computing topographic stress using Green’s functions, finding that topography can induce appreciable crustal stress. We develop a new method for incorporating depth information about resistivity, density, and topographic stresses into our previously published equations to calculate resource probability and confidence. We incorporate newly collected and modeled data into our calculations to update statewide maps of probability and confidence. Lana‘i Island and southeast Mauna Kea are identified as the top targets for exploratory drilling. The east rift of Haleakala Volcano, the southern-most region of Mauna Loa’s SW rift (Hawai‘i Island), and central Kauai are identified as targets for geophysical surveying.

15 GEOTHERMAL ENERGY↗
DOE OSTI2020

Prussian blue analogues as platform materials for understanding and developing oxygen evolution reaction electrocatalysts

Transition metal based materials containing Fe have drawn great attention as oxygen evolution reaction (OER) catalysts. The nature of the electrocatalytic active species remains under debate due to the ambiguous physicochemical properties of the catalyst materials, such as the oxidation states and crystal structures. Here, in order to address this issue, transition metal Prussian blue analogues (TM-PBA, Na(TM)(Fe)(CN) 6 , TM = V, Fe, Co, and Ni) with an isomorphous structure are investigated for OER catalysis. Our combined experimental measurements and density functional theory (DFT) calculations reveal that TM-PBAs exhibit volcano-like OER activity with Ni-PBA located near the top of the volcano. Such a volcano-like activity profile can be attributed to the distinctive binding energy difference between *O and *OH on different TM-PBAs surfaces. This research demonstrates that TM-PBAs can be used as platform materials for understanding structure-property-activity relationships in OER catalysts.

25 ENERGY STORAGE↗
DOE OSTI2023

Revised Nitrogen Reduction Scaling Relations from Potential-Dependent Modeling of Chemical and Electrochemical Steps

The electrochemical nitrogen reduction reaction (NRR) is a promising route to enable carbon-free ammonia production. However, this reaction is limited by the poor activity and selectivity of current catalysts. The rational design of superior NRR electrocatalysts requires a detailed mechanistic understanding of current material limitations to inform how these might be overcome. The current understanding of how scaling limits NRR on metal catalysts is predicated on a simplified reaction pathway that considers only proton-coupled electron transfer (PCET) steps. Here, we apply grand-canonical density functional theory to investigate a more comprehensive NRR mechanism that includes both electrochemical and chemical steps on 30 metal surfaces in solvent under an applied potential. We applied ..phi..max, a grand-canonical adaptation of the Gmax thermodynamic descriptor, to evaluate trends in catalyst activity. This approach produces a ..phi..max "volcano" diagram for NRR activity scaling on metals that qualitatively differs from the scaling relations identified when only PCET steps are considered. NH3* desorption was found to limit the NRR activity for materials at the top of the volcano and truncate the volcano's peak at increasingly reducing potentials. These revised scaling relations may inform the rational design of superior NRR electrocatalysts. This approach is transferable to study other materials and reaction chemistries where both electrochemical and chemical steps are modeled under an applied potential.

electrocatalysis↗
DOE OSTI2022

Trans-crustal structural control of CO 2 -rich extensional magmatic systems revealed at Mount Erebus Antarctica

Erebus volcano, Antarctica, with its persistent phonolite lava lake, is a classic example of an evolved, CO 2 -rich rift volcano. Seismic studies provide limited images of the magmatic system. Here we show using magnetotelluric data that a steep, melt-related conduit of low electrical resistivity originating in the upper mantle undergoes pronounced lateral re-orientation in the deep crust before reaching shallower magmatic storage and the summit lava lake. The lateral turn represents a structural fault-valve controlling episodic flow of magma and CO 2 vapour, which replenish and heat the high level phonolite differentiation zone. This magmatic valve lies within an inferred, east-west structural trend forming part of an accommodation zone across the southern termination of the Terror Rift, providing a dilatant magma pathway. Unlike H 2 O-rich subduction arc volcanoes, CO 2 -dominated Erebus geophysically shows continuous magmatic structure to shallow crustal depths of < 1 km, as the melt does not experience decompression-related volatile supersaturation and viscous stalling.

58 GEOSCIENCES↗
DOE OSTI2022

Global patterns of diversity and metabolism of microbial communities in deep-sea hydrothermal vent deposits

When deep-sea hydrothermal fluids mix with cold oxygenated fluids, minerals precipitate out of solution and form hydrothermal deposits. These actively venting deep-sea hydrothermal deposits support a rich diversity of thermophilic microorganisms which are involved in a range of carbon, sulfur, nitrogen, and hydrogen metabolisms. Global patterns of thermophilic microbial diversity in deep-sea hydrothermal ecosystems have illustrated the strong connectivity between geological processes and microbial colonization, but little is known about the genomic diversity and physiological potential of these novel taxa. Here we explore this genomic diversity in 42 metagenomes from four deep-sea hydrothermal vent fields and a deep-sea volcano collected from 2004 to 2018 and document their potential implications in biogeochemical cycles. Our dataset represents 3635 metagenome-assembled genomes encompassing 511 novel and recently identified genera from deep-sea hydrothermal settings. Some of the novel bacterial (107) and archaeal genera (30) that were recently reported from the deep-sea Brothers volcano were also detected at the deep-sea hydrothermal vent fields, while 99 bacterial and 54 archaeal genera were endemic to the deep-sea Brothers volcano deposits. We report some of the first examples of medium- (≥ 50% complete, ≤ 10% contaminated) to high-quality (> 90% complete, < 5% contaminated) MAGs from phyla and families never previously identified, or poorly sampled, from deep-sea hydrothermal environments. We greatly expand the novel diversity of Thermoproteia, Patescibacteria (Candidate Phyla Radiation, CPR), and Chloroflexota found at deep-sea hydrothermal vents and identify a small sampling of two potentially novel phyla, designated JALSQH01 and JALWCF01. Metabolic pathway analysis of metagenomes provides insights into the prevalent carbon, nitrogen, sulfur, and hydrogen metabolic processes across all sites and illustrates sulfur and nitrogen metabolic “handoffs” in community interactions. We confirm that Campylobacteria and Gammaproteobacteria occupy similar ecological guilds but their prevalence in a particular site is driven by shifts in the geochemical environment. Our study of globally distributed hydrothermal vent deposits provides a significant expansion of microbial genomic diversity associated with hydrothermal vent deposits and highlights the metabolic adaptation of taxonomic guilds. Collectively, our results illustrate the importance of comparative biodiversity studies in establishing patterns of shared phylogenetic diversity and physiological ecology, while providing many targets for enrichment and cultivation of novel and endemic taxa.

59 BASIC BIOLOGICAL SCIENCES↗