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A New Analysis of Caldera Unrest through the Integration of Geophysical Data and FEM Modeling: The Long Valley Caldera Case Study. REMOTE SENSING 2021. [DOI: 10.3390/rs13204054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Long Valley Caldera, located at the eastern edge of the Sierra Nevada range in California, has been in a state of unrest since the late 1970s. Seismic, gravity and geodetic data strongly suggest that the source of unrest is an intrusion beneath the caldera resurgent dome. However, it is not clear yet if the main contribution to the deformation comes from pulses of ascending high-pressure hydrothermal fluids or low viscosity magmatic melts. To characterize the nature of the intrusion, we developed a 3D finite element model which includes topography and crust heterogeneities. We first performed joint numerical inversions of uplift and Electronic Distance Measurement baseline length change data, collected during the period 1985–1999, to infer the deformation-source size, position, and overpressure. Successively, we used this information to refine the source overpressure estimation, compute the gravity potential and infer the intrusion density from the inversion of deformation and gravity data collected in 1982–1998. The deformation source is located beneath the resurgent dome, at a depth of 7.5 ± 0.5 km and a volume change of 0.21 ± 0.04 km3. We assumed a rhyolite compressibility of 0.026 ± 0.0011 GPa−1 (volume fraction of water between 0% and 30%) and estimated a reservoir compressibility of 0.147 ± 0.037 GPa−1. We obtained a density of 1856 ± 72 kg/m3. This density is consistent with a rhyolite melt, with 20% to 30% of dissolved hydrothermal fluids.
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Li BQ, Smith JD, Ross ZE. Basal nucleation and the prevalence of ascending swarms in Long Valley caldera. SCIENCE ADVANCES 2021; 7:7/35/eabi8368. [PMID: 34452917 PMCID: PMC8397262 DOI: 10.1126/sciadv.abi8368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Earthquake swarms are ubiquitous in volcanic systems, being manifestations of underlying nontectonic processes such as magma intrusions or volatile fluid transport. The Long Valley caldera, California, is one such setting where episodic earthquake swarms and persistent uplift suggest the presence of active magmatism. We quantify the long-term spatial and temporal characteristics of seismicity in the region using cluster analysis on a 25-year high-resolution earthquake catalog derived using leading-edge deep-learning algorithms. Our results show that earthquake swarms beneath the caldera exhibit enlarged families with statistically significant tendency for upward migration patterns. The ascending swarms tend to nucleate at the base of the seismogenic zone with a spatial footprint that is laterally constrained by the southern rim of the caldera. We suggest that these swarms are driven by the transport of volatile-rich fluids released from deep volcanic processes. The observations highlight the potential for extreme spatial segmentation of earthquake triggering processes in magmatic systems.
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Affiliation(s)
- Bing Q Li
- Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA.
- Department of Civil and Environmental Engineering, Western University, London, ON, Canada
| | - Jonathan D Smith
- Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
| | - Zachary E Ross
- Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
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Pritchard ME, Mather TA, McNutt SR, Delgado FJ, Reath K. Thoughts on the criteria to determine the origin of volcanic unrest as magmatic or non-magmatic. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180008. [PMID: 30966934 PMCID: PMC6335482 DOI: 10.1098/rsta.2018.0008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/24/2018] [Indexed: 06/02/2023]
Abstract
As our ability to detect volcanic unrest improves, we are increasingly confronted with the question of whether the unrest has a magmatic origin (magma on the move) or a non-magmatic origin from a change in the hydrothermal system (fluids that are not magma on the move) or tectonic processes. The cause of unrest has critical implications for the potential eruptive hazard (e.g. used in constructing Bayesian Event Trees), but is frequently the subject of debate, even at well-studied systems. Here, we propose a set of multi-disciplinary observations and numerical models that could be used to evaluate conceptual models about the cause of unrest. These include measurements of gas fluxes and compositions and the isotopic signature of some components (e.g. H2, He, C, SO2, H2 O, CH4 and CO2), the spatial and temporal characteristics of ground deformation, thermal output, seismicity, changes in gravity, and whether there is topographic uplift or subsidence spanning hundreds to thousands of years. In several volcanic systems, both magmatic and non-magmatic unrest is occurring at the same time. While none of these observations or models is diagnostic on its own, we illustrate several examples where they have been used together to make a plausible conceptual model of one or more episodes of unrest and whether eruptions did or did not follow the unrest. This article is part of the Theo Murphy meeting issue 'Magma reservoir architecture and dynamics'.
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Affiliation(s)
- M. E. Pritchard
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA
| | - T. A. Mather
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - S. R. McNutt
- School of Geosciences, University of South Florida, 4202 E. Fowler Avenue, NES 107, Tampa, FL 33620, USA
| | - F. J. Delgado
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA
| | - K. Reath
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA
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Tree-ring width reveals the preparation of the 1974 Mt. Etna eruption. Sci Rep 2017; 7:44019. [PMID: 28266610 PMCID: PMC5339818 DOI: 10.1038/srep44019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 02/02/2017] [Indexed: 11/08/2022] Open
Abstract
Reduced near-infrared reflectance observed in September 1973 in Skylab images of the western flank of Mt. Etna has been interpreted as an eruption precursor of the January 1974 eruption. Until now, it has been unclear when this signal started, whether it was sustained and which process(es) could have caused it. By analyzing tree-ring width time-series, we show that the reduced near-infrared precursory signal cannot be linked to a reduction in annual tree growth in the area. However, comparing the tree-ring width time-series with both remote sensing observations and volcano-seismic activity enables us to discuss the starting date of the pre-eruptive period of the 1974 eruption.
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Seiler R, Kirchner JW, Krusic PJ, Tognetti R, Houlié N, Andronico D, Cullotta S, Egli M, D'Arrigo R, Cherubini P. Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy). PLoS One 2017; 12:e0169297. [PMID: 28099435 PMCID: PMC5242533 DOI: 10.1371/journal.pone.0169297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/14/2016] [Indexed: 11/26/2022] Open
Abstract
On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We consequently aimed at determining whether an increase in ambient temperature or additional water availability owing to the rise of magma and degassing of water vapour prior to the eruption could have increased photosynthesis of Mt. Etna's trees. Using dendro-climatic analyses we quantified the sensitivity of tree ring widths to temperature and precipitation at high elevation stands on Mt. Etna. Our findings suggest that tree growth at high elevation on Mt. Etna is weakly influenced by climate, and that neither an increase in water availability nor an increase in temperature induced by pre-eruptive activity is a plausible mechanism for enhanced photosynthesis before the 2002/2003 flank eruption. Our findings thus imply that other, yet unknown, factors must be sought as causes of the pre-eruption enhancement of NDVI on Mt. Etna.
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Affiliation(s)
- Ruedi Seiler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Department of Geography, University of Zurich, Zürich, Switzerland
- * E-mail:
| | - James W. Kirchner
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Department of Environmental Systems Science, ETH Zurich, Zürich, Switzerland
| | - Paul J. Krusic
- Navarino Environmental Observatory, Messinia, Greece
- Institutionen för Naturgeografi, Stockholm University, Sweden
| | - Roberto Tognetti
- Dipartimento di Bioscienze e territorio, Università del Molise, Contrada Fonte Lappone, Pesche, Italy
| | - Nicolas Houlié
- Department of Earth Sciences, ETH Zurich, Zürich, Switzerland
| | | | | | - Markus Egli
- Department of Geography, University of Zurich, Zürich, Switzerland
| | - Rosanne D'Arrigo
- Lamont-Doherty Earth Observatory, Palisades, New York, United States of America
| | - Paolo Cherubini
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Department of Geography, University of Zurich, Zürich, Switzerland
- Lamont-Doherty Earth Observatory, Palisades, New York, United States of America
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Vanorio T, Kanitpanyacharoen W. ROCK PHYSICS. Rock physics of fibrous rocks akin to Roman concrete explains uplifts at Campi Flegrei Caldera. Science 2015; 349:617-21. [PMID: 26160377 DOI: 10.1126/science.aab1292] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/17/2015] [Indexed: 11/03/2022]
Abstract
Uplifts in the Campi Flegrei caldera reach values unsurpassed anywhere in the world (~2 meters). Despite the marked deformation, the release of strain appears delayed. The rock physics analysis of well cores highlights the presence of two horizons, above and below the seismogenic area, underlying a coupled process. The basement is a calc-silicate rock housing hydrothermal decarbonation reactions, which provide lime-rich fluids. The caprock above the seismogenic area has a pozzolanic composition and a fibril-rich matrix that results from lime-pozzolanic reactions. These findings provide evidence for a natural process reflecting that characterizing the cementitious pastes in modern and Roman concrete. The formation of fibrous minerals by intertwining filaments confers shear and tensile strength to the caprock, contributing to its ductility and increased resistance to fracture.
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Affiliation(s)
- Tiziana Vanorio
- Stanford Rock Physics Laboratory, Department of Geophysics, Stanford University, Stanford, CA 94305, USA.
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Feng L, Newman AV. Constraints on continued episodic inflation at Long Valley Caldera, based on seismic and geodetic observations. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb006240] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jahr T, Jentzsch G, Gebauer A, Lau T. Deformation, seismicity, and fluids: Results of the 2004/2005 water injection experiment at the KTB/Germany. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008jb005610] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chang WL, Smith RB, Wicks C, Farrell JM, Puskas CM. Accelerated uplift and magmatic intrusion of the Yellowstone caldera, 2004 to 2006. Science 2007; 318:952-6. [PMID: 17991858 DOI: 10.1126/science.1146842] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Yellowstone caldera began a rapid episode of ground uplift in mid-2004, revealed by Global Positioning System and interferometric synthetic aperture radar measurements, at rates up to 7 centimeters per year, which is over three times faster than previously observed inflation rates. Source modeling of the deformation data suggests an expanding volcanic sill of approximately 1200 square kilometers at a 10-kilometer depth beneath the caldera, coincident with the top of a seismically imaged crustal magma chamber. The modeled rate of source volume increase is 0.1 cubic kilometer per year, similar to the amount of magma intrusion required to supply the observed high heat flow of the caldera. This evidence suggests magma recharge as the main mechanism for the accelerated uplift, although pressurization of magmatic fluids cannot be ruled out.
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Affiliation(s)
- Wu-Lung Chang
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA.
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Bartel BA, Hamburger MW, Meertens CM, Lowry AR, Corpuz E. Dynamics of active magmatic and hydrothermal systems at Taal Volcano, Philippines, from continuous GPS measurements. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb002194] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Beth A. Bartel
- Department of Geological Sciences; Indiana University; Bloomington Indiana USA
| | | | | | - Anthony R. Lowry
- Department of Physics; University of Colorado; Boulder Colorado USA
| | - Ernesto Corpuz
- Philippine Institute of Volcanology and Seismology; Department of Science and Technology; Quezon City Philippines
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Furuya M, Okubo S, Sun W, Tanaka Y, Oikawa J, Watanabe H, Maekawa T. Spatiotemporal gravity changes at Miyakejima Volcano, Japan: Caldera collapse, explosive eruptions and magma movement. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb001989] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Masato Furuya
- Earthquake Research Institute; University of Tokyo; Tokyo Japan
| | - Shuhei Okubo
- Earthquake Research Institute; University of Tokyo; Tokyo Japan
| | - Wenke Sun
- Earthquake Research Institute; University of Tokyo; Tokyo Japan
| | | | - Jun Oikawa
- Earthquake Research Institute; University of Tokyo; Tokyo Japan
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Prejean S, Ellsworth W, Zoback M, Waldhauser F. Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jb001168] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Stephanie Prejean
- Department of Geophysics; Stanford University; Stanford California USA
| | | | - Mark Zoback
- Department of Geophysics; Stanford University; Stanford California USA
| | - Felix Waldhauser
- Department of Geophysics; Stanford University; Stanford California USA
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Lundgren P, Usai S, Sansosti E, Lanari R, Tesauro M, Fornaro G, Berardino P. Modeling surface deformation observed with synthetic aperture radar interferometry at Campi Flegrei caldera. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jb000194] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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