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Fumarole

A fumarole is a vent or opening in the Earth's surface, typically in volcanic regions, through which steam and volcanic gases such as carbon dioxide, sulfur dioxide, hydrogen sulfide, and hydrogen chloride are emitted, often accompanied by a hissing or roaring sound.^[1]^[2]^[3] These features form when groundwater or surface water is heated by underlying magma or hot rocks, flashing into steam that escapes along cracks, fissures, or chaotic clusters.^[1]^[2] Fumaroles vary in size and activity, ranging from small holes emitting gentle vapors to large fissures releasing intense jets of gas, and they can persist for decades or centuries if sustained by a persistent heat source like magma chambers, or last only weeks to months on cooling lava flows or pyroclastic deposits.^[1]^[3] The gases and steam often deposit minerals such as sulfur and opal around the vent, leading to colorful encrustations and hydrothermal alteration of surrounding rocks.^[2] In some cases, limited water supply causes the liquid to vaporize completely before surfacing, making fumaroles the hottest type of hydrothermal feature, with temperatures exceeding 300°F (149°C).^[2] These vents are commonly found near active or dormant volcanoes, including in national parks and geothermal areas across the globe.^[2] Notable examples include the thousands of fumaroles in Yellowstone National Park's Norris Geyser Basin and Roaring Mountain, where they hiss continuously; the high-temperature Big Boiler in Lassen Volcanic National Park's Bumpass Hell, reaching 322°F (161°C); and active sites on Kīlauea Volcano in Hawaiʻi Volcanoes National Park, as well as in Alaska's Katmai, Lake Clark, and Aniakchak parks.^[2]^[1] Fumaroles also occur in regions like the Valley of Ten Thousand Smokes in Alaska, a vast field of extinct vents from a 1912 eruption.^[2] Fumaroles play a crucial role in volcanology by providing direct samples of subsurface gases, which scientists analyze to monitor magma movement, assess eruption risks, and forecast volcanic activity through changes in gas composition, emission rates, and temperatures.^[1] However, they pose hazards due to toxic, invisible gases that can accumulate in low areas, causing respiratory issues or asphyxiation, and unstable ground around vents that may collapse.^[2] Additionally, fumarolic emissions contribute to atmospheric sulfur aerosols and support unique extremophile microbial communities in harsh conditions.^[1]^[2]

Definition and Characteristics

Definition

A fumarole is an opening in the Earth's crust or a planetary surface that chronically emits steam and volcanic gases, often without significant ash or lava.^[1]^[3] These features represent a surface manifestation of subsurface heat and fluid movement, where superheated water and gases escape through fractures or vents.^[2] Fumaroles can vary in scale from small cracks to larger fissures and are commonly associated with volcanic regions, though they may persist long after major eruptive activity ceases.^[3] The term "fumarole" derives from the Latin fumus, meaning "smoke," reflecting the visible vapor plumes often observed; it entered English usage in geological literature around 1811 via French fumerolle.^[1]^[4] This etymology underscores the feature's characteristic emission of steamy fumes, though the output is primarily water vapor and gases rather than combustion products.^[1] Unlike eruptive volcanic vents, which discharge molten material, ash, and fragments during explosive events, fumaroles are generally non-explosive and maintain steady, persistent emissions over extended periods, sometimes for decades or centuries above sustained heat sources.^[3]^[2] Fumaroles form as a consequence of volcanism, driven by magmatic heat that boils groundwater and liberates trapped volatiles, without involving the detailed mechanics of magma ascent.^[5] This process links them fundamentally to planetary volcanic activity, with analogous features identified in extraterrestrial contexts such as Mars.^[6]

Physical Characteristics

Fumaroles typically appear as small openings or vents in the Earth's surface, varying in size from tiny cracks mere centimeters wide to larger fissures or orifices up to several meters across, often occurring in clusters, chaotic fields, or linear alignments along fractures. These morphological features can include irregular funnel-shaped structures in non-welded volcanic deposits, facilitating the escape of gases through permeable pathways. The surrounding areas frequently exhibit colorful mineral encrustations formed by condensation of emitted vapors, such as bright yellow sulfur crystals, variably hued native sulfur ranging from pink to dark gray, opalescent silica deposits, and other minerals like gypsum and hematite, which create visually striking halos around the vents.^[3]^[7]^[2]^[8] Environmental indicators of active fumaroles include prominent steam plumes rising up to 150 meters high, making them visible from afar, as well as characteristic hissing or growling sounds produced by escaping gases. These features often correlate with barren, altered soil zones devoid of vegetation, resulting from the harsh conditions near the emissions. Fumarole activity displays variability in expression, ranging from diffuse soil degassing over broad areas to concentrated flows from discrete vents, largely governed by subsurface permeability that directs gas migration through fractures or porous media.^[2]^[9]^[10] Initial field assessments of fumaroles commonly involve thermocouples inserted or placed directly onto vent surfaces for accurate temperature measurements, while infrared imaging enables remote detection of thermal anomalies across larger areas without direct contact. These methods provide essential data on vent activity and heat output, aiding in the monitoring of hydrothermal systems.^[11]^[12]

Formation and Types

Geological Formation

Fumaroles primarily form through the heating of groundwater by subsurface magmatic sources or geothermal gradients, which vaporizes the water into steam that escapes to the surface along fractures and fissures. This process is driven by heat transfer from molten magma or cooling intrusive bodies, causing meteoric water—derived from precipitation—to circulate downward, absorb heat, and ascend as superheated vapor mixed with other volatiles. In volcanic settings, this steam-dominated emission creates the characteristic vents observed at the surface.^[2] Key geological processes sustaining fumaroles include hydrothermal circulation, where convecting fluids form loops in permeable rock layers, transporting heat and dissolved gases upward; degassing from underlying magma chambers, as rising pressure decreases allow volatiles to exsolve and permeate through the crust; and tectonic faulting, which reactivates fractures to provide preferential pathways for gas migration. These mechanisms often interconnect in a magma-hydrothermal regime, where magmatic fluids interact with circulating groundwater, enhancing fluid boiling and pressure buildup that propels emissions. Conceptual cross-sections of such systems illustrate downward-percolating cold water heated at depth, forming buoyant plumes that fracture overlying rocks to reach the surface.^[13]^[14]^[15] Fumaroles evolve through stages tied to volcanic activity, beginning during active phases with direct magmatic degassing and intense hydrothermal boiling near eruptive centers, transitioning to post-eruptive residual activity in dormant volcanoes where lingering geothermal heat from solidified intrusions sustains lower-output vents for centuries. As the heat source cools, fumarolic activity diminishes, potentially leading to extinction if fluid recharge or permeability declines.^[1] Influencing factors include rock permeability, which determines the ease of fluid and gas escape through fractures versus sealing by mineral precipitation; water availability from regional aquifers or rainfall, ensuring a continuous steam supply; and pressure changes, such as those from tectonic stress or magma withdrawal, that can trigger sudden degassing episodes or alter vent locations. These elements collectively control the longevity and intensity of fumarolic systems.^[2]^[16]

Classification of Fumaroles

Fumaroles are classified primarily based on their temperature, gas flux rates, duration and variability of activity, and associations with other hydrothermal features, providing a framework for understanding their role in volcanic systems. Temperature serves as a key criterion, with high-temperature fumaroles exceeding 100°C often linked to direct magmatic influence, while low-temperature ones below 100°C typically reflect shallower hydrothermal processes.^[17] Gas flux rates further categorize them, ranging from low-output diffuse emissions to high-flux point sources that can exceed several tons of gas per day, influencing local atmospheric and environmental impacts.^[18] Associations with features like hot springs indicate integrated hydrothermal systems where fumaroles contribute to broader fluid circulation.^[19] Activity duration and variability yield main types: perpetual fumaroles exhibit constant emissions over extended periods in persistently active volcanic settings, temporary ones arise post-eruptively and diminish as magmatic heat wanes, and seasonal variants fluctuate with precipitation-driven groundwater recharge, altering steam production. Perpetual types maintain steady output, as observed in long-term monitoring of active craters.^[1] Temporary fumaroles often emerge immediately after eruptions, signaling residual heat and degassing before fading.^[20] Seasonal influences, such as increased activity during wet periods due to enhanced boiling, highlight hydrological controls on emission patterns.^[21] Subtypes based on dominant emissions include solfataras, characterized by sulfur-rich gases like SO₂ and H₂S, mofettes dominated by CO₂ at lower temperatures, and steam vents primarily releasing water vapor. Solfataras derive their name from the Italian term for sulfur, reflecting historical observations at sites like the Solfatara crater near Naples, where sulfurous fumes were noted in ancient accounts. Mofettes, originating from Italian "mofeta" denoting a moldy exhalation and later applied to cold CO₂ vents in Central European volcanic fields, represent a late-stage degassing phase. Steam vents, a broader category, emphasize H₂O output without specifying other gases, often overlapping with the above in mixed systems.^[22] This classification supports volcanic monitoring and forecasting by correlating changes in type or intensity—such as a shift from temporary to perpetual activity—with underlying magmatic or tectonic unrest, enabling early detection of potential eruptions through integrated gas and thermal surveillance.^[23]

Chemical Composition

Emitted Gases

Fumarole emissions are dominated by water vapor (H₂O), which constitutes 50–95% of the total gas output, alongside major components such as carbon dioxide (CO₂) and sulfur dioxide (SO₂), and lesser amounts of hydrogen sulfide (H₂S), with trace constituents including hydrogen chloride (HCl), hydrogen fluoride (HF), and noble gases like helium and argon.^[24]^[25] These proportions can vary by site, but H₂O often arises from both magmatic fluids and condensed groundwater, while CO₂ and SO₂ typically reflect deeper volcanic sources.^[25] The origins of these gases are tied to distinct geological processes: SO₂ and CO₂ primarily stem from magmatic degassing, where volatiles exsolve from ascending magma in the Earth's crust, whereas H₂S forms through water-rock interactions in hydrothermal systems, often via reduction of sulfate minerals or thermochemical reactions involving sulfur species.^[25] Isotopic analysis provides key insights into sourcing; for instance, δ¹³C values of CO₂ ranging from -8‰ to -3‰ indicate a predominantly magmatic mantle origin, while more positive values suggest contributions from crustal carbonates or organic matter.^[26] Noble gas isotopes, such as ³He/⁴He ratios exceeding atmospheric levels, further confirm magmatic inputs by tracing helium from the mantle.^[26] Detection of fumarole gases employs a suite of analytical techniques for precise characterization. Laboratory methods like gas chromatography separate and quantify gas mixtures, while mass spectrometry identifies specific species and their isotopic compositions; these are often applied to samples collected via direct sampling tubes or Multi-GAS instruments that measure H₂O, CO₂, SO₂, and H₂S in real time.^[25] Remote sensing via spectroscopy, including ultraviolet (UV) and Fourier-transform infrared (FTIR) methods, enables non-invasive monitoring of plumes from afar, with differential optical absorption spectroscopy (DOAS) deployed on unmanned aircraft for elevated fumaroles.^[25] A common chemical transformation observed is the atmospheric oxidation of H₂S, exemplified by the reaction:

$2\mathrm{H_2S} + 3\mathrm{O_2} \rightarrow 2\mathrm{SO_2} + 2\mathrm{H_2O}

which converts reduced sulfur to oxidized forms, influencing downwind compositions.^[27] Temporal variations in gas composition serve as indicators of subsurface dynamics, with shifts such as rising SO₂ fluxes or increasing CO₂/SO₂ ratios signaling magmatic recharge and potential unrest.^[25] For example, elevated CO₂/SO₂ ratios months before the 2009 eruption of Redoubt Volcano suggested deepening degassing depths, while at Kīlauea in 2018, changes in H₂S and SO₂ tracked the progression of eruptive activity.^[25] Such monitoring, combining isotopic trends like δ¹³C enrichment with gas ratio anomalies, helps forecast volcanic behavior by revealing interactions between magmatic and hydrothermal fluids.^[26]^[25]

Temperature Variations

Fumaroles exhibit a wide range of temperatures depending on their proximity to magmatic heat sources and environmental conditions. In low-energy hydrothermal fields, temperatures often remain near boiling (~100°C), as seen in peripheral vents where boiling groundwater dominates. Conversely, fumaroles in high-energy volcanic settings near active magma chambers can reach superheated conditions exceeding 400°C, with recorded maxima up to 800–900°C in some cases. These extremes reflect the transition from hydrothermal to magmatic-dominated systems.^[11]^[28]^[29] Several factors influence fumarole temperatures, primarily the depth to the underlying heat source, which determines the initial thermal energy available for gas ascent. Shallower depths to magma or hot intrusions result in higher surface temperatures due to reduced conductive heat loss along the conduit. Gas expansion during ascent leads to cooling through adiabatic processes, where the gas loses heat as it expands without external heat exchange, often lowering temperatures by tens to hundreds of degrees from source depths. Atmospheric mixing, including diurnal pressure variations and precipitation, further modulates surface readings; for instance, rainfall can cause rapid temperature drops by infiltrating and cooling vents, while barometric changes alter gas flow rates.^[30]^[31]^[30] Temperatures are measured using a combination of direct and remote techniques to capture both point-specific and field-scale data. Direct probes, such as thermocouples or infrared radiometers inserted into vents, provide precise readings for individual fumaroles, often yielding values from 100°C to over 500°C in active sites. Infrared thermography via handheld or fixed cameras maps thermal anomalies across larger areas, identifying hot spots with resolutions down to centimeters. For expansive fields, satellite remote sensing, like NASA's ASTER instrument, detects diffuse heat fluxes over kilometers using thermal infrared bands, estimating average temperature excesses of 4–10°C above ambient for monitoring long-term trends.^[28]^[28] Sudden temperature spikes in fumaroles often serve as indicators of heightened volcanic activity, potentially preceding eruptions by days to months. These increases, sometimes exceeding 50°C, correlate with seismic swarms and fracturing that enhance permeability and heat transfer from depth, as observed in systems like Vulcano where spikes followed high-frequency earthquakes. Such precursors highlight the role of thermal monitoring in assessing unrest, though they must be interpreted alongside other geophysical signals.^[32]^[32]

Human Interactions

Economic Uses

Fumaroles serve as significant sources of geothermal energy, where superheated steam and hot fluids are harnessed to generate electricity and provide direct heating applications. In dry steam geothermal systems, vapor emitted directly from fumaroles drives turbines in power plants, a method pioneered at Larderello in Tuscany, Italy, where the world's first geothermal electricity generation occurred in 1904 using steam to power an experimental dynamo that lit five bulbs. This site, rich in fumarolic activity, expanded into the first commercial geothermal plant by 1913, producing up to 250 kW and demonstrating the viability of exploiting volcanic steam for baseload power without fuel combustion. Today, similar dry steam facilities, such as those in California's Geysers field, continue to utilize fumarole-like vents to generate renewable electricity, contributing to stable energy output with capacities exceeding 700 MW historically, though output has declined due to resource depletion. For lower-temperature fumaroles, binary cycle plants employ a secondary working fluid to transfer heat from geothermal fluids to turbines, enhancing efficiency in areas like New Zealand's Taupo Volcanic Zone, where fumarolic steam supports over 800 MW of installed capacity. Beyond electricity, fumaroles enable direct-use geothermal applications, including district heating, agricultural drying, and spa operations, leveraging the consistent heat from steam vents for economic benefits in rural communities. In Iceland and New Zealand, geothermal heat from fumarole fields powers greenhouses for year-round crop production and fish farming, reducing reliance on imported fuels and supporting local economies through energy cost savings estimated at up to 30% compared to conventional heating. These applications prioritize sites with stable steam flow and minimal corrosive gases to ensure long-term viability. Fumaroles also facilitate mineral extraction, particularly sulfur and boric acid, from condensates and deposits formed by volcanic gases. At Larderello, boric acid production began in the 19th century by condensing steam from fumaroles, yielding a key antiseptic and industrial chemical that predated electricity generation and drove early economic development in the region. Sulfur mining from fumarolic sublimates remains active at sites like Kawah Ijen in Indonesia, where miners manually collect up to 14 tons daily from vent pipes channeling volcanic gases, exporting the mineral for use in fertilizers, rubber vulcanization, and sulfuric acid production, generating vital income in remote areas despite hazardous conditions. Historical sulfur extraction from volcanic fumaroles in Sicily during the 14th century supplied gunpowder manufacturing across Europe, underscoring the long-standing economic role of these deposits. Tourism represents another economic avenue, with fumarole fields drawing visitors to witness geothermal spectacles and participate in related activities. In Ischia, Italy, the Maronti Beach fumaroles heat black sand to over 100°C, attracting tourists for natural steam baths and culinary experiences like baking bread in volcanic pits, contributing to the island's €500 million annual tourism revenue. Similarly, the Poça da Dona Beija site in Portugal's Azores features accessible fumarole pools used for therapeutic soaking, bolstering eco-tourism that emphasizes volcanic heritage and generates employment in guided tours and hospitality. Scientific drilling around fumaroles supports geothermal exploration and research, enabling resource assessment and technology testing that informs broader energy projects. In the Azores, Portugal, exploratory wells near fumarolic zones have mapped subsurface reservoirs, facilitating investments in sustainable power generation and reducing exploration risks through data on steam purity and flow rates. Economic viability of fumarole exploitation hinges on factors such as gas composition, with high steam purity minimizing equipment corrosion, and stable output to ensure reliable revenue streams. Sites with low non-condensable gases like hydrogen sulfide allow for higher efficiency, as seen in Italy's Tuscany fields producing approximately 6,000 GWh annually (as of 2024) with reinjection techniques to sustain pressure. Recent advancements in the 2020s include agreements to utilize separated CO2 from geothermal plants for industrial applications, such as producing food-grade CO2, which helps reduce direct emissions and supports environmental goals.^[33]

Associated Hazards

Fumaroles pose significant health risks to humans primarily through the emission of toxic gases, such as hydrogen sulfide (H₂S), which can cause respiratory failure and other severe effects upon inhalation.^[34] Exposure to H₂S at concentrations above 100 ppm can lead to immediate collapse and death due to its interference with cellular respiration, while lower levels may cause irritation of the eyes, throat, and lungs.^[35] Additionally, hot steam emanating from fumaroles can result in severe burns to the skin and respiratory tract, particularly in close proximity to vents.^[36] Asphyxiation is another critical danger, especially in low-lying or confined areas where denser gases like carbon dioxide (CO₂) accumulate, displacing oxygen and leading to suffocation, as documented in fatal incidents at volcanic sites.^[37] Environmentally, fumarole emissions contribute to acid rain formation through sulfur dioxide (SO₂), which reacts with atmospheric water to produce sulfuric acid, lowering precipitation pH and harming aquatic and terrestrial ecosystems.^[37] This acidification leaches essential nutrients from soil while mobilizing toxic metals like aluminum, leading to soil contamination that inhibits plant growth and microbial activity.^[38] Ecosystem disruption is evident in areas with persistent emissions, where high CO₂ levels in soils stunt or kill vegetation, causing localized barren zones and broader biodiversity loss.^[37] Long-term effects include deforestation, as acid rain weakens tree canopies and roots, making forests more susceptible to dieback, particularly in montane regions near active vents.^[39] Fumaroles threaten infrastructure by accelerating corrosion of metals and materials due to acidic gases and high temperatures, which degrade equipment, pipelines, and buildings in proximity.^[40] Hydrothermal alteration from fumarolic fluids weakens surrounding rock, reducing shear strength and promoting ground instability that can culminate in collapses or landslides.^[41] Such instability has been linked to edifice failures at volcanoes, where altered zones act as failure planes, endangering roads, utilities, and settlements.^[42] Mitigation of fumarole hazards involves deploying gas monitoring networks to detect elevated levels of toxic emissions in real-time, enabling timely alerts.^[43] Warning systems, including seismic and gas sensors, integrate with evacuation protocols to protect communities, as implemented by observatories like the USGS Hawaiian Volcano Observatory.^[44] A notable case occurred during the 2018 Kīlauea summit collapses, where continuous monitoring of gas plumes and ground deformation facilitated park closures and evacuations, preventing casualties amid explosive events and hazardous gas releases.^[45]

Occurrences

Terrestrial Examples

Fumarole fields are prominent in volcanic settings across North America, exemplified by the Yellowstone Caldera in Wyoming, USA, where diverse gases including carbon dioxide, hydrogen sulfide, methane, nitrogen, carbon monoxide, and helium escape through numerous vents, reflecting contributions from magmatic, crustal, and atmospheric sources.^[46] These fumaroles, part of the park's extensive hydrothermal system, exhibit varied chemistry such as elevated ammonium and mercury in acid-sulfate features, highlighting the caldera's active geothermal dynamics.^[47] Similarly, at Mount St. Helens in Washington, USA, increased fumarolic activity served as a key precursor to the major 1980 eruption, with heightened gas emissions and related stream acidification observed in the preceding months, underscoring fumaroles' role in signaling eruptive unrest.^[48]^[49] In Europe, the Solfatara di Pozzuoli within the Campi Flegrei caldera near Naples, Italy, represents a historically significant volcanic site, known since ancient Roman times as the domain of Vulcan, the god of fire, where fumaroles have continuously emitted steam and gases, drawing early observations of geothermal phenomena.^[50] These vents maintain temperatures around 147–149°C, contributing to the area's ongoing hydrothermal activity without recent eruptions.^[51] Further north, Iceland's Reykjanes Peninsula hosts geothermal areas like Gunnuhver and Seltún, where low-temperature fumaroles, mud pools, and steam vents emerge from tectonic rifts, creating colorful landscapes driven by shallow hydrothermal circulation rather than active magmatism.^[52]^[53] In the Asia-Pacific region, the Philippines' Taal Volcano has shown notable fumarole activity in the 2020s, with persistent gas-and-steam emissions from summit vents observed during ongoing unrest, including elevated plumes rising hundreds of meters amid Alert Level 1 status, as part of post-2020 monitoring efforts.^[54] Complementing this, New Zealand's Rotorua geothermal field provides examples of low-temperature fumaroles, where steam vents and associated features like mud pools operate at surface temperatures below 100°C, sustained by regional heat flow in the Taupō Volcanic Zone and integrated into sustainable energy practices.^[55]^[56] Historically, fumaroles have signaled eruptive precursors, as seen at Mount St. Helens, where pre-1980 intensification of vent activity and gas release indicated magma ascent, informing modern hazard assessments.^[57] Post-2020, monitoring of fumaroles worldwide has seen enhancements through remote sensing and drone-based gas sampling, partly to investigate climate-volcano interactions such as how glacial retreat influences hydrothermal systems and degassing rates.^[25]^[58] These advancements allow for real-time tracking of gas fluxes, aiding in the detection of subtle environmental feedbacks.

Extraterrestrial Occurrences

Fumaroles, or gas vents associated with volcanic or hydrothermal activity, have been inferred or directly observed on several extraterrestrial bodies through planetary missions, extending the concept beyond Earth to environments driven by diverse geological processes. On Mars, the Curiosity rover has detected hints of sulfur-bearing gases and evidence of past hydrothermal activity in Gale Crater during its exploration in the 2010s, suggesting potential cryovolcanic fumaroles that could have released volatiles like sulfur dioxide from subsurface reservoirs. These findings, including pure sulfur crystals exposed in 2024, indicate episodic gas emissions possibly linked to ancient geothermal systems, though no active vents have been confirmed.^[59]^[60] Jupiter's moon Io exhibits the most intense volcanic activity in the Solar System, with plumes interpreted as fumarolic emissions powered by tidal heating from Jupiter's gravitational pull. These plumes, first imaged by the Voyager missions in 1979 and studied extensively by Galileo from 1995 to 2003, eject sulfur dioxide and other gases up to hundreds of kilometers high, forming colorful deposits on the surface. Recent James Webb Space Telescope (JWST) observations in the 2020s have detected sulfur emissions at 1.707 microns during eruptions, confirming ongoing gas venting from multiple sites.^[61]^[62] On Venus, Magellan mission radar data from the 1990s revealed possible active volcanic vents contributing to the planet's sulfuric acid atmosphere, with changing lava flows at sites like Maat Mons suggesting gas emissions including sulfur compounds that form acid droplets. Saturn's moon Enceladus features icy geysers at its south pole, observed by Cassini from 2005 to 2017, which serve as analogs to fumaroles by expelling water vapor, organics, and salts from a subsurface ocean through cryovolcanic processes. These plumes, driven by hydrothermal activity, provide geothermal energy that could support habitability.^[63] Detection of such features relies on orbital spectroscopy to identify gas signatures like SO₂ absorption lines and lander instruments for direct sampling of volatiles, as demonstrated by Curiosity's mass spectrometer on Mars. In astrobiology, these extraterrestrial fumaroles highlight potential niches for life, where geothermal heat and chemical gradients from gas emissions could sustain microbial ecosystems, analogous to Earth but adapted to extreme conditions.^[64]

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Jul 31, 2021 · We conclude that hydrothermal alteration decreases volcano stability and thus expedites volcano spreading and increases the likelihood of mass wasting events.
[39]
Hidden mechanical weaknesses within lava domes provided by ...
Feb 25, 2022 · Indeed, previous studies have highlighted that weakened hydrothermally altered zones can promote volcano instability and collapse, but the ...
[40]
Who monitors volcanic gases emitted by Kīlauea and how is it done?
... water vapor, in addition to carbon dioxide and sulfur dioxide. This straightforward discovery overturned a popular volatile theory of the day and, in the ...
[41]
Geologic Investigations of the Kīlauea Summit Collapse - USGS.gov
Data from this instrument allowed USGS to advise Hawaiʽi Volcanoes National Park (HAVO) on potential hazards and for HAVO to take effective hazard mitigation ...
[42]
[PDF] Volcanic Hazard at the Summit of Kīlauea: June 29, 2018 Update
Jun 29, 2018 · This document is a guide for understanding current activity and hazard at and around the summit of Kīlauea Volcano.
[43]
Capturing Yellowstone's elusive gases - USGS.gov
Nov 1, 2020 · Other gases escaping with water vapor, such as carbon dioxide (CO2), hydrogen sulfide (H2S), methane, nitrogen, carbon monoxide, and helium, are ...
[44]
The diverse chemistry of Yellowstone's hydrothermal features
Dec 16, 2019 · Some acid-sulfate waters contain elevated concentrations of ammonium and mercury. These features tend to be fumaroles, mud pots, or acid-sulfate ...
[45]
[PDF] Mount St. Helens A bibliography of geoscience literature, 1882-1986
22). In March 1980 scientists detected increased seismic activity followed by releases of ash and by other changes in the volcano, which culminated in ...
[46]
Monitoring Volcanoes (U.S. National Park Service)
Aug 7, 2024 · On 2 April 1980, “Operators of a fish hatchery some 5 miles from Mount St. Helens reported a decrease in pH from 6.8 to 5.8 caused by stream ...
[47]
Volcanoes, archaeology and the secrets of Roman concrete
Feb 26, 2019 · Solfatara crater, home of Vulcan, the Roman god of fire, gurgles on the edge of town. And just offshore, sculptures, thermal baths, a villa, ...
[48]
Campi Flegrei - Global Volcanism Program
The temperatures of the fumaroles in the Solfatara crater are 147-149°C, the same as those measured by Tazieff in 1967 and those reported by D.E. White for ...Missing: ancient | Show results with:ancient
[49]
Gunnuhver Geothermal Area Travel Guide - Guide to Iceland
Gunnuhver is the name of an impressive and colourful geothermal field of various mud pools and fumaroles in the southwest part of the Reykjanes Peninsula.
[50]
The history of Seltún Geothermal Area - Visit Reykjanes
Apr 29, 2024 · Seltún Geothermal Area forms part of the Seltún Krýsuvík Geothermal Field. Its hot springs, solfataras, fumaroles and mud pools make it an interesting visitor ...
[51]
Smithsonian / USGS Weekly Volcanic Activity Report
May 15, 2024 · The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger ...
[52]
Surface features - Geothermal - Bay Of Plenty Regional Council
Geothermal surface features in New Zealand are hydrothermal in nature (water or steam dominated) with most groupings having gradational boundaries.
[53]
Geothermal energy | Te Ara Encyclopedia of New Zealand
Geothermal systems occur where circulating groundwater is heated and rises as a column of hot water to the surface.
[54]
Understanding and forecasting phreatic eruptions driven by ...
May 18, 2018 · This paper examines phreatic eruptions which are driven by inputs of magma and magmatic gas. We synthesize data from several significant phreatic systems.
[55]
[PDF] Volcanic Diffuse Volatile Emissions Tracked by Plant Responses ...
Mar 11, 2023 · We detected increases in plant stress caused by increases in soil temperature and sulfur emissions before they were detectable by other types of ...
[56]
Formation of Tridymite and Evidence for a Hydrothermal History at ...
Dec 11, 2020 · In August 2015, the Curiosity Mars rover discovered tridymite, a high-temperature silica polymorph, in Gale crater. The existing model for ...
[57]
Active Volcanic Plumes on Io | NASA Jet Propulsion Laboratory (JPL)
Mar 26, 1998 · Plumes on Io have a blue color, so the plume shadow is reddish. The Prometheus plume can be seen in every Galileo image with the appropriate ...
[58]
An Energetic Eruption With Associated SO 1.707 Micron Emissions ...
Jul 18, 2023 · The James Webb Space Telescope (JWST) presents an opportunity to observe Io's 1.707-μm forbidden SO emission without the need for AO.2 Jwst Observations · 3 Results · 4.2 So Emissions
[59]
Magellan Spacecraft Uncovers Signs of Active Volcanism on Venus
Apr 15, 2023 · Researchers analyzing Magellan spacecraft radar images discovered a changing volcanic vent on Venus, providing new evidence of active ...
[60]
A Low-Diversity Microbiota Inhabits Extreme Terrestrial Basaltic ...
Mar 6, 2019 · The planet Mars, which sits in the outer regions of the so-called “habitable zone,” is today a cold desert-like world dominated by basaltic ...