Skip to main content
Advanced Search

Filters: Tags: caldera (X)

22 results (73ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
Long Valley Caldera in eastern California formed 0.76 Ma ago in a cataclysmic eruption that resulted in the deposition of 600 km3 of Bishop Tuff. The total current heat flow from the caldera floor is estimated to be ~ 290 MW, and a geothermal power plant in Casa Diablo on the flanks of the resurgent dome (RD) generates ~40 MWe. The RD in the center of the caldera was uplifted by ~ 80 cm between 1980 and 1999 and was explained by most models as a response to magma intrusion into the shallow crust. This unrest has led to extensive research on geothermal resources and volcanic hazards in the caldera. Here we present results from precise, high-resolution, temperature–depth profiles in five deep boreholes (327–1,158...
thumbnail
The San Juan Mountains in southwestern Colorado have long been recognized as a site of exceptionally voluminous mid-Tertiary volcanism, including at least 24 major ignimbrite sheets (each 150-5,000 km3) and associated caldera structures active at 33-23 Ma. More recent volcanologic and petrologic studies in the San Juan region have focused mainly on several ignimbrite-caldera systems: the southeastern area (Platoro complex), western calderas (Uncompahgre-Silverton-Lake City), the central cluster (La Garita-Creede calderas). The northeast San Juan region that was far less studied until recently occupies a transition between earlier volcanism in central Colorado and the larger-volume younger ignimbrite-caldera foci...
thumbnail
The Taupo Volcanic Zone (TVZ), New Zealand, is the most productive area of explosive silicic volcanism in the world. Faulted early and middle Pleistocene volcanic products are generally concealed beneath voluminous, generally unfaulted, younger volcanic products. An exception is the southeast margin of the TVZ where the two parallel, northeast-trending Paeroa and Te Weta Fault blocks expose Quaternary volcanic products consisting predominantly of caldera-related, rhyolitic ignimbrites and lacustrine sediments. The Taupo-Reporoa Basin is situated along the eastern part of the map area, and its northernmost part underwent collapse to form Reporoa Caldera. The Paeroa Fault block is the largest exposed fault block within...
Although giant calderas (“supervolcanoes”) may slumber for tens of thousands of years between eruptions, their abundant earthquakes and crustal deformation reveal the potential for future upheaval. Any eventual supereruption could devastate global human populations, so these systems must be carefully scrutinized. Insight into dormant but restless calderas can be gained by monitoring their output of heat and gas. At Yellowstone, the large thermal and CO2 fluxes require massive input of basaltic magma, which continues to invade the lower to mid-crust, sustains the overlying high-silica magma reservoir, and may result in volcanic hazard for millennia to come. The high flux of CO2 may contribute to the measured deformation...
thumbnail
Aerial photography surveys during and after the 2018 eruption of Veniaminof Volcano, Alaska were conducted to track the evolution of the lava flow field, active volcanic vent, and glacial ice loss from the eruption. Imagery from two surveys was processed with structure-from-motion (SfM) photogrammetric methods to derive the digital elevation models (DEMs) and orthophotos in this data release. The datasets cover the active volcanic cone and intracaldera ice cap, which both show significant topographic and groundcover change between surveys, and relative to previous topographic reference data, due to the 2018 eruption and variable snow and ice cover. A syn-eruption survey on September 26, 2018 was conducted by the...
thumbnail
Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The...
thumbnail
Okmok volcano, Aleutian Islands, Alaska, explosively erupted over a five-week period between July 12 and August 23, 2008. The eruption was predominantly phreatomagmatic, producing fine-grained tephra that covered most of northeastern Umnak Island. The eruption had a maximum Volcanic Explosivity Index (VEI) of 4, with eruption column heights up to 16 km during the opening phase. Several craters and a master tuff cone formed in the caldera as a result of phreatomagmatic explosions and accumulated tephra-fall and surge deposits. Ascending magma continuously interacted with an extensive shallow groundwater table in the caldera, resulting in the phreatomagmatic character of the eruption. Syneruptive explosion and collapse...
thumbnail
This database was prepared using a combination of materials that include aerial photographs, topographic maps (1:24,000 and 1:250,000), field notes, and a sample catalog. Our goal was to translate sample collection site locations at Yellowstone National Park and surrounding areas into a GIS database. This was achieved by transferring site locations from aerial photographs and topographic maps into layers in ArcMap. Each field site is located based on field notes describing where a sample was collected. Locations were marked on the photograph or topographic map by a pinhole or dot, respectively, with the corresponding station or site numbers. Station and site numbers were then referenced in the notes to determine...
Inflation and deflation of large calderas is traditionally interpreted as being induced by volume change of a discrete source embedded in an elastic or viscoelastic half-space, though it has also been suggested that hydrothermal fluids may play a role. To test the latter hypothesis, we carry out numerical simulations of hydrothermal fluid flow and poroelastic deformation in calderas by coupling two numerical codes: (1) TOUGH2 [Pruess et al., 1999], which simulates flow in porous or fractured media, and (2) BIOT2 [Hsieh, 1996], which simulates fluid flow and deformation in a linearly elastic porous medium. In the simulations, high-temperature water (350°C) is injected at variable rates into a cylinder (radius 50...
thumbnail
LiDAR scans were taken using a tripod mounted Riegl VZ-400 scanning LiDAR. The tripod was set up such that the scanner was between 1.5 and 2.5 m tall. The VZ-400 is a near infrared (1550 nm) scanner. Geometric control was achieved using a pair of Trimble RB GPS antennae, one mounted on the LiDAR scanner (rover) and the other setup as a base station. Before taking a LiDAR scan, the VZ-400 would use the GPS to fix a real time kinematic (RTK) solution for the scanner’s location and then use that position (scan position) as a reference for LiDAR returns. Post processing was done using RIScan-Pro version 2 (scanner specific software). Also, in post-processing, overlapping areas of point clouds were merged and inaccuracies...
This dataset contains Unoccupied Aircraft Systems (UAS) footage from the 2018 summit collapse of Kīlauea Volcano, Island of Hawai‘i. The intrusion of magma into Kīlauea’s lower East Rift Zone triggered draining of the summit lava lake and magma withdrawal from the shallow reservoir. This resulted in 62 subsequent collapse events at the summit between May and early-August 2018. Each collapse event released energy equivalent to a magnitude-5.3 earthquake. The total collapse volume was about 0.8 km^3, with subsidence of more than 500 m in some places. There are 73 UAS videos in this publication, recorded from May 19 to September 5, which have been separated into subpages by month. Sub-pages for each month also contain...
The dataset includes whole-rock geochemistry, phenocryst/mineral trace element compositions, zircon U–Pb geochronology, and zircon in situ Lu–Hf isotopes for intrusions associated with the Oligocene Platoro caldera complex of the San Juan volcanic locus in Colorado features numerous exposed plutons, both within the caldera and outside its margins, enabling investigation of the timing and evolution of postcaldera magmatism. Intrusion and , coupled with new document distinct pulses of magma derived from different depths beneath the caldera complex. Fourteen intrusions, the Chiquito Peak Tuff, and the dacite of Fisher Gulch were dated, showing intrusive magmatism began after the 28.8 Ma-eruption of the Chiquito Peak...
Ground surface displacement (GSD) in large calderas is often interpreted as resulting from magma intrusion at depth. Recent advances in geodetic measurements of GSD, notably interferometric synthetic aperture radar, reveal complex and multifaceted deformation patterns that often require complex source models to explain the observed GSD. Although hydrothermal fluids have been discussed as a possible deformation agent, very few quantitative studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent increases in the power and availability of computing resources allow robust quantitative assessment of the complex time‐variant thermal interplay between aqueous fluid flow and crustal...
Categories: Publication; Types: Citation; Tags: caldera, hydrothermal, model
thumbnail
Fisher volcano, containing the largest Holocene caldera in the Aleutian volcanic arc, is an active volcano near the center of Unimak Island, about 120 kilometers southwest of Cold Bay and about 175 kilometers northeast of Dutch Harbor. The volcano is composed of numerous small volcanic centers around and within a large, oval caldera 12 by 18 kilometers in diameter and 500 to 1,000 meters deep that formed during a catastrophic eruption about 9,400 years ago. Since then, more than 30 separate vents inside and outside the caldera have erupted; the most recent eruption occurred in 1826. These eruptions have produced lava flows and widespread tephra (volcanic ash) deposits, and have occasionally been accompanied by large...
Inflation and deflation of large calderas is traditionally interpreted as being induced by volume change of a discrete source embedded in an elastic or viscoelastic half-space, though it has also been suggested that hydrothermal fluids may play a role. To test the latter hypothesis, we carry out numerical simulations of hydrothermal fluid flow and poroelastic deformation in calderas by coupling two numerical codes: (1) TOUGH2 [Pruess et al., 1999], which simulates flow in porous or fractured media, and (2) BIOT2 [Hsieh, 1996], which simulates fluid flow and deformation in a linearly elastic porous medium. In the simulations, high-temperature water (350°C) is injected at variable rates into a cylinder (radius 50...
thumbnail
Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The...
thumbnail
This Raw Data File presents major-oxide glass geochemical results from the ca. 3.6 ka caldera-forming eruption of Aniakchak volcano, Alaska. These data are part of a larger effort to identify and characterize tephra deposits from the largest eruptions in Alaska for use as geochronological marker horizons. Aniakchak is one of at least 29 volcanoes in Alaska that has had multiple large tephra-producing eruptions. Other deposit and sample metadata including geospatial distributions of this tephra deposit are held in the Alaska Volcano Observatory's online database, the Geologic Database of Information on Volcanoes in Alaska (GeoDIVA), and will be linked to these new geochemical data once published. Products included...


map background search result map search result map Geologic Map of the Tularosa Mountains 30� � 60� Quadrangle, Catron County, New Mexico Generalized Geologic Map of the Upper Animas River Watershed and Vicinity, Silverton, Colorado Geology of Kasatochi volcano, Aleutian Islands, Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska Major-element glass compositions of tephra from the circa 3.6 ka eruption of Aniakchak volcano, Alaska Peninsula, Alaska Preliminary volcano-hazard assessment for Fisher volcano, Unimak Island, Alaska The 2008 phreatomagmatic eruption of Okmok Volcano, Aleutian Islands, Alaska: Chronology, deposits, and landform changes Database for the Geologic Map of the Bonanza Caldera Area, Northeastern San Juan Mountains, Colorado Database for the geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand UAS video of the 2018 summit eruption of Kīlauea Volcano—May 1-31, 2018 Petrologic data for 'Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountains Volcanic Field, Colorado' Digital elevation models and orthoimagery from the 2018 eruption of Veniaminof, Alaska Yellowstone Sample Collection - database NASA GIFT Iceland Highlands: 2019 Oskjuvatn LiDAR NASA GIFT Iceland Highlands: 2019 Oskjuvatn LiDAR Digital elevation models and orthoimagery from the 2018 eruption of Veniaminof, Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska UAS video of the 2018 summit eruption of Kīlauea Volcano—May 1-31, 2018 Database for the geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand Generalized Geologic Map of the Upper Animas River Watershed and Vicinity, Silverton, Colorado Petrologic data for 'Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountains Volcanic Field, Colorado' Database for the Geologic Map of the Bonanza Caldera Area, Northeastern San Juan Mountains, Colorado The 2008 phreatomagmatic eruption of Okmok Volcano, Aleutian Islands, Alaska: Chronology, deposits, and landform changes Yellowstone Sample Collection - database Preliminary volcano-hazard assessment for Fisher volcano, Unimak Island, Alaska