Article
Geochemistry & Geophysics
Minoru Takeo
Summary: This study proposes a source model for harmonic tremors, explaining the mechanism of volcanic seismic tremors through the effects of non-linear viscous fluid flow in a flexible channel. The model successfully simulates the frequency peaks and phase portraits of harmonic tremors observed during the 2011 Shinmoe-dake eruption.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Tomofumi Kozono, Satoshi Okumura
Summary: We investigated the essential factors controlling magma fragmentation during moderate-intensity explosive eruptions by combining observational data and analytical expressions. Our study revealed that a drastic increase in magma viscosity induced by magma crystallization plays a crucial role in the occurrence of fragmentation. The viscosity increase is closely related to the microscopic structure of crystal-bearing magma, highlighting the importance of combining petrological information and conduit flow modeling for understanding the magma ascent process during moderate-intensity explosive eruptions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Patrick R. Phelps, Helge M. Gonnermann, Heather Winslow, Philipp Ruprecht, Matthew E. Pritchard, Francisco Delgado, Yang Liao
Summary: The 2011-2012 eruption at Cordon Caulle in Chile produced crystal-poor rhyolitic magma with crystal-rich mafic enclaves. It is believed that the eruptible rhyolites are associated with crystal-rich magma mushes, and the enclaves within the Cordon Caulle rhyolite confirm the existence of such a magma mush. The inflation observed during and after the eruption may be attributed to magma segregation from a crystal mush, leading to an increase in system volume.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
C. Novoa, M. Gerbault, D. Remy, J. Cembrano, L. E. Lara, J. Ruz-Ginouves, A. Tassara, J. C. Baez, R. Hassani, S. Bonvalot, R. Contreras-Arratia
Summary: This study uses synthetic aperture radar (SAR) imagery to analyze the ground displacements before, during, and after the 2011-2012 Cordon-Caulle eruption in Chile. The researchers find that a similar prolate spheroidal source explains the ground deformation for the pre-eruptive and post-eruptive periods. They also use 3D numerical elasto-plastic models to assess the failure conditions resulting from pre-eruptive magma injection. The study suggests that the eruption may have been triggered by slip motion along a fault system or collapse of the caldera.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Diego Gonzalez-Vidal, Christoph Sens-Schoenfelder, Jose Luis Palma, Felipe Quiero, Luis Franco, Matthew Miller, Dietrich Lange, Gerd Sielfeld, Jose Cembrano
Summary: Volcano seismology is a crucial tool in monitoring volcanic activities and predicting eruptions. Various seismic signals, including the newly discovered VLP signal, can provide important information about the migration of fluids inside volcanoes. Our observation at Villarrica volcano in 2015 reveals the correlation between LP and VLP signals, shedding light on the fluxes in the magmatic reservoir and aiding volcanic forecasting.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Franziska Keller, Olivier Bachmann, Nobuo Geshi, Ayumu Miyakawa
Summary: The Aso-4 caldera-forming event is the second largest volcanic eruption Earth experienced in the past 100 ka, resulting in ignimbrite sheets with clear compositional, mineralogical, and thermal gradients. These gradients are primarily attributed to extensive magma mixing of two compositionally distinct magmas in a complex upper crustal reservoir rather than solely magma mixing.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Theodorus Permana, Takeshi Nishimura, Hisashi Nakahara, Nikolai Shapiro
Summary: Classification of volcanic tremors and earthquakes using seismic wave correlation analysis provides a valuable tool for monitoring volcanic activities. This study developed a classification technique based on spatial coherence analysis of seismic signals and applied it to data from Sakurajima volcano in Japan. The results showed that the classification method could effectively distinguish volcanic tremors and B-type earthquakes, and the activity patterns matched well with observations made by the Japan Meteorological Agency.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Qing-Yu Wang, Michel Campillo, Florent Brenguier, Albanne Lecointre, Tetsuya Takeda, Keisuke Yoshida
Summary: Using ambient-noise-based seismic monitoring, we detected an anomalous seismic velocity decrease in Honshu about one year after the 2011 Tohoku-Oki earthquake, suggesting a possible relation to volcanic processes and internal physical changes. Tiltmeter observations revealed temporal variations correlated with velocity changes, supporting the hypothesis of actual physical deformation in the crust. The observed decrease in fault strength and concurrent increase in low-frequency events in the volcanic area further indicate changes in physical properties and an increase in pore pressure in the upper crust.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Multidisciplinary Sciences
Heather Winslow, Philipp Ruprecht, Helge M. Gonnermann, Patrick R. Phelps, Carolina Munoz-Saez, Francisco Delgado, Matthew Pritchard, Alvaro Amigo
Summary: Two distinct types of rare crystal-rich mafic enclaves have been identified in the rhyolite lava flow from the 2011-12 Cordon Caulle eruption. These enclaves, including coarse-crystalline and porphyritic types, have compositions that differ significantly from the rhyolite host. The presence of interstitial melt in the enclaves suggests a direct derivation of the crystal-poor rhyolite magma from the underlying basaltic magma mush, bypassing the typical magmatic differentiation process.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
David P. Sahara, Puput P. Rahsetyo, Andri Dian Nugraha, Devy Kamil Syahbana, Sri Widiyantoro, Zulfakriza Zulfakriza, Ardianto Ardianto, Aria W. Baskara, Shindy Rosalia, Martanto Martanto, Haunan Afif
Summary: This study analyzes pre-eruptive seismicity events for volcano eruption forecasting and identifies two types of seismic activity related to magma intrusion. By improving the accuracy of hypocenter locations, the study provides a better understanding of the subsurface structure of the volcano.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Yanfang Qin, Yasuyuki Nakamura, Shuichi Kodaira, Gou Fujie
Summary: This study collected seismic data from different regions along the Japan trench during the 2011 Tohoku earthquake to investigate the impact of along-trench structures on seismic activities. The study found variations in geological structures, such as differences in sediment thickness and the presence of fold-and-thrust belts in the south. These structural variations influence shallow megathrust slip and tsunami generation.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Tomofumi Kozono, Takehiro Koyaguchi, Hideki Ueda, Taku Ozawa, Tadashi Yamasaki
Summary: Based on the relationship between geodetic volume change of magma chamber and erupted magma volume, this study investigated the magma storage conditions prior to the 2011 and 2018 eruptions at Kirishima Shinmoe-dake volcano in Japan. The study derived an analytical expression for the volume ratio, which is strongly dependent on the effective compressibility of the magma chamber and related parameters. The results suggest efficient gas segregation from the chamber occurred prior to the eruptions.
EARTH PLANETS AND SPACE
(2023)
Article
Remote Sensing
Simon Plank, Francesco Massimetti, Arianna Soldati, Kai-Uwe Hess, Michael Nolde, Sandro Martinis, Donald B. Dingwell
Summary: The 2018 lower East Rift Zone eruption at Kilauea Volcano was the largest event in the last 200 years, with an estimated lava volume of 9.24 x 10(8) m(3). The eruption began on May 3, with increasing lava effusion rates throughout May and reaching a peak of 137.67 m(3) s(-1) by the beginning of August.
INTERNATIONAL JOURNAL OF REMOTE SENSING
(2021)
Article
Geosciences, Multidisciplinary
Koki Yoshinaga, Takeshi Matsushima, Hiroshi Shimizu, Yusuke Yamashita, Ken'ichi Yamazaki, Shintaro Komatsu, Satoshi Fujiwara
Summary: Using strain and tilt observations, we have inferred the temporal changes in pressure sources that caused crustal deformation during the eruption of Shinmoe-dake volcano in 2018. Our findings reveal that the deep magmatic activity associated with the early stages of the eruption began approximately 19 hours earlier than previously estimated. Tilt changes observed during the eruption coincided with lava outflow and dome formation, indicating the deflation of a spherical pressure source.
EARTH PLANETS AND SPACE
(2023)
Article
Geosciences, Multidisciplinary
V. D. Espinosa, J. L. Arce, R. Castro-Govea
Summary: The Malinche Pumice II is a fallout deposit from a Plinian-type eruption during the Pleistocene-Holocene, produced by one of the largest explosive eruptions of the La Malinche volcano involving a dacitic magma. The eruption was likely triggered by an input of hotter and deeper magma batch, leading to overpressurization of the magma system and eventual vesiculation and fragmentation. The shift to a hydromagmatic style was caused by entrainment of external water, decreasing the vesicularity of the pumice.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2021)
Article
Geochemistry & Geophysics
Naoto Mizuno, Mie Ichihara, Nobuki Kame
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2015)
Article
Geosciences, Multidisciplinary
Mie Ichihara, Tetsuya Kusakabe, Nobuki Kame, Hiroyuki Kumagai
EARTH PLANETS AND SPACE
(2016)
Article
Geochemistry & Geophysics
Mie Ichihara
EARTH AND PLANETARY SCIENCE LETTERS
(2008)
Article
Geosciences, Multidisciplinary
Mie Ichihara, John J. Lyons, Akihiko Yokoo
EARTH PLANETS AND SPACE
(2013)
Article
Geosciences, Multidisciplinary
Masaharu Kameda, Hideaki Kuribara, Mie Ichihara
GEOPHYSICAL RESEARCH LETTERS
(2008)
Article
Geosciences, Multidisciplinary
M. Ichihara, M. Takeo, A. Yokoo, J. Oikawa, T. Ohminato
GEOPHYSICAL RESEARCH LETTERS
(2012)
Article
Geochemistry & Geophysics
M. Ichihara, M. B. Rubin
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2010)
Article
Geosciences, Multidisciplinary
Masaharu Kameda, Mie Ichihara, Susumu Shimanuki, Wataru Okabe, Tsukasa Shida
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2013)
Article
Physics, Fluids & Plasmas
Valerie Vidal, Mie Ichihara, Maurizio Ripepe, Kei Kurita
Article
Geochemistry & Geophysics
John J. Lyons, Mie Ichihara, Aika Kurokawa, Jonathan M. Lees
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2013)
Article
Geosciences, Multidisciplinary
M Ichihara, EE Brodsky
GEOPHYSICAL RESEARCH LETTERS
(2006)
Article
Geosciences, Multidisciplinary
M Ichihara, H Ohkunitani, Y Ida, M Kameda
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2004)
Article
Geochemistry & Geophysics
M Ichihara, D Rittel, B Sturtevant
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2002)