scholarly journals Statistical analysis of crystal populations and links to volcano deformation for more robust estimates of magma replenishment volumes

Geology ◽  
2019 ◽  
Vol 47 (12) ◽  
pp. 1171-1175
Author(s):  
Lilu Cheng ◽  
Fidel Costa
Keyword(s):  
Statistical Approach ◽  
Population Analysis ◽  
Volcanic Eruptions ◽  
Plumbing System ◽  
Volcano Deformation ◽  
Merapi Volcano ◽  
Robust Estimates ◽  
Minimum Estimate ◽  
Proper Interpretation ◽  
Magma Replenishment

Abstract Forecasting the timing and size of volcanic eruptions requires a proper interpretation of multiparametric monitoring signals. Studies of the erupted rocks can provide critical information on the processes and volcano plumbing system that is needed to decode the monitoring signals. Here we present the results of a petrological study of plagioclase phenocrysts using a new statistical approach that allows us to estimate the amount of intruded magma before eruption. Our crystal population analysis of the 2006 and 2010 CE Merapi volcano (Indonesia) eruptions shows that ∼60 ± 20 vol% of the 2010 magma was left over from the 2006 magma, and thus ∼40 ± 20 vol% was newly intruded magma. Using the published values of the 2010 erupted magma volume, this corresponds to >8 to 20 (±7) × 106 m3 of new magma. This is a minimum estimate and is similar to the inferred pre-eruptive deformation volume (18 ×106 m3), although given the uncertainties, several million cubic meters of magma intruded in 2010 could still be in the Merapi plumbing system. Our approach could be used at other volcanoes to quantify the volume of intruded magma and thus help in better understanding the unrest signals that anticipate eruptions.

Forecast of the Pyroclastic Volume by Precursory Seismicity of Merapi Volcano

2019 ◽  
Vol 14 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Masato Iguchi ◽  
Haruhisa Nakamichi ◽  
Kuniaki Miyamoto ◽  
Makoto Shimomura ◽  
I Gusti Made Agung Nandaka ◽  
...  
Keyword(s):  
Seismic Energy ◽  
Volcanic Eruptions ◽  
Pyroclastic Flows ◽  
Energy Calculation ◽  
Cumulative Energy ◽  
Merapi Volcano ◽  
Tectonic Earthquakes ◽  
Order Of Magnitude ◽  
The Difference ◽  
Log Linear

We propose a method to evaluate the potential volume of eruptive material using the seismic energy of volcanic earthquakes prior to eruptions of Merapi volcano. For this analysis, we used well-documented eruptions of Merapi volcano with pyroclastic flows (1994, 1997, 1998, 2001, 2006, and 2010) and the rates and magnitudes of volcano-tectonic A-type, volcano-tectonic B-type, and multiphase earthquakes before each of the eruptions. Using the worldwide database presented by White and McCausland [1], we derived a log-linear formula that describes the upper limit of the potential volume of erupted material estimated from the cumulative seismic energy of distal volcano-tectonic earthquakes. The relationship between the volume of pyroclastic material and the cumulative seismic energy released in 1994, 1997, 1998, 2001, 2006, and 2010 at Merapi volcano is well-approximated by the empirical formula derived from worldwide data within an order of magnitude. It is possible to expand this to other volcanic eruptions with short (< 30 years) inter-eruptive intervals. The difference in the intruded and extruded volumes between intrusions and eruptions, and the selection of the time period for the cumulative energy calculation are problems that still need to be addressed.

scholarly journals The Reconstruction of Disaster Knowledge through Thematic Learning of Science, Environment, Technology, and Society Integrated with Local Wisdom

2018 ◽  
Vol 7 (2) ◽  
pp. 204-213 ◽  
Author(s):  
S. E. Atmojo ◽  
A. Rusilowati ◽  
S. I. A. Dwiningrum ◽  
M. Skotnicka
Keyword(s):  
Elementary Schools ◽  
Disaster Management ◽  
Volcanic Eruptions ◽  
Disaster Mitigation ◽  
Technology And Society ◽  
Merapi Volcano ◽  
Gain Score ◽  
Central Java ◽  
Disaster Knowledge ◽  
Thematic Learning

This study aimed to improve the mastery of knowledge, attitudes, and skills of students in disaster mitigation in prone areas of volcanic eruptions. The subjects of this research were fifth (V) graders in three elementary schools situated in prone areas of Merapi volcano eruption in Srumbung subdistrict, Magelang regency, Central Java. The data collected in this study consisted of disaster knowledge, attitude, and mitigation practice. The data of disaster knowledge were obtained through a test and analyzed using t-test and N-gain. The attitude data were collected using questionnaire with an improvement analysis using N-gain. The mitigation practice data were collected through observation and analyzed by descriptive percentage for attitudes and skills. The research results showed that the implementation of thematic learning of Science, Environment, Technology, and Society (SETS) integrated with local wisdom was able to reconstruct and increase the disaster management knowledge. This can be seen from the N-gain score obtained by each elementary school which the highest Gain Score was 0.46 and included in the medium category. There was an enhancement attitude toward disaster having the highest Gain Score was 0.77. All disaster mitigation indicators were successfully mastered by more than 70 percent of the students, who were in the good category (70≥X≤85) in all three elementary schools implementing the thematic learning of SETS integrated with local wisdom.

scholarly journals Deep Magma Transport Control on the Size and Evolution of Explosive Volcanic Eruptions

2021 ◽  
Vol 9 ◽  
Author(s):  
Simone Colucci ◽  
Paolo Papale
Keyword(s):  
Volcanic Eruptions ◽  
Explosive Eruptions ◽  
Magma Storage ◽  
Plumbing System ◽  
Flow Rates ◽  
Surrounding Environment ◽  
Transport Control ◽  
Mass Flow Rates ◽  
Explosive Volcanic Eruptions ◽  
Surface Manifestation

Explosive eruptions are the surface manifestation of dynamics that involve transfer of magma from the underground regions of magma accumulation. Evidence of the involvement of compositionally different magmas from different reservoirs is continuously increasing to countless cases. Yet, models of eruption dynamics consider only the uppermost portion of the plumbing system, neglecting connections to deeper regions of magma storage. Here we show that the extent and efficiency of the interconnections between different magma storage regions largely control the size of the eruptions, their evolution, the causes of their termination, and ultimately their impact on the surrounding environment. Our numerical simulations first reproduce the magnitude-intensity relationship observed for explosive eruptions on Earth and explain the observed variable evolutions of eruption mass flow rates. Because deep magmatic interconnections are largely inaccessible to present-day imaging capabilities, our results motivate the need to better image and characterize extant magma bodies.

scholarly journals Amphibole megacrysts as a probe into the deep plumbing system of Merapi volcano, Central Java, Indonesia

2017 ◽  
Vol 172 (4) ◽  
Author(s):  
Stefan T. M. Peters ◽  
Valentin R. Troll ◽  
Franz A. Weis ◽  
Luigi Dallai ◽  
Jane P. Chadwick ◽  
...  
Keyword(s):  
Plumbing System ◽  
Merapi Volcano ◽  
Central Java

scholarly journals Establishing genetic relationships between the Takidani pluton and two large silicic eruptions in the Northern Japan Alps

2021 ◽  
Author(s):  
Eva Hartung ◽  
Luca Caricchi ◽  
David Floess ◽  
Simon Wallis ◽  
Satoru Harayama
Keyword(s):  
Genetic Relationships ◽  
Volcanic Eruptions ◽  
Substantial Contribution ◽  
Plumbing System ◽  
Pyroclastic Deposits ◽  
Trace Element Chemistry ◽  
Magmatic Reservoir ◽  
Progressive Growth ◽  
Caldera Floor ◽  
Magmatic Plumbing System

Abstract The Takidani pluton (1.1-1.6 Ma) represents a shallow magmatic reservoir at the base of an exhumed caldera floor. The deposits of two large caldera-forming eruptions including the Nyukawa Pyroclastic Flow Deposit (1.76 Ma; crystal-rich dacite) and the Chayano Tuff and Ebisutoge Pyroclastic Deposits (1.75 Ma; a sequence of crystal-poor rhyolite) are distributed concentrically around the pluton. We use major and trace element chemistry of whole-rock, glass and minerals to show (1) that the crystal-rich dacite (&gt;400 km3 DRE; dense rock equivalent) is the erupted portion of a shallow mush zone constituting the Takidani pluton and (2) that the crystal-poor rhyolite (&gt;100 km3 DRE) was extracted from a deeper part of this vertically extended magmatic plumbing system. Whole-rock geochemistry indicates that the Nyukawa and Takidani compositions were produced dominantly through crystal fractionation of amphibole, pyroxene and plagioclase in the mid-to-lower crust and subsequently emplaced in the upper crust prior to eruption and solidification, respectively. The crystal-poor Chayano-Ebisutoge rhyolite (&gt;100 km3 DRE) is compositionally distinct from the Nyukawa and Takidani magmas and its generation is associated with a substantial contribution of crustal melts. Yet, plagioclase and orthopyroxene textures and chemistry provide strong evidence that the ascending rhyolite percolated through the upper Takidani-Nyukawa mush zone prior to eruption. Overgrowth of “rhyolitic plagioclase” on “xenocrystic dacitic plagioclase” typical of the Takidani-Nyukawa magmas indicates that the extraction and accumulation of the rhyolitic melts could have occurred in less than 10 kyr (i.e. time between eruptions) prior to eruption providing maximum timescales for pre-eruption storage. Overall, our findings show a progressive growth and thermal maturation of a vertically extended magmatic plumbing system over hundreds of thousands of years and imply that large volcanic eruptions can occur in relatively short succession without dramatic changes in the plumbing system, thus, complicating the identification of signs of an impending large eruption.

Special Issue on Integrated Study on Mitigation of Multimodal Disasters Caused by Ejection of Volcanic Products

2016 ◽  
Vol 11 (1) ◽  
pp. 3-3
Author(s):  
Masato Iguchi ◽  
Keyword(s):  
Scientific Knowledge ◽  
Volcanic Ash ◽  
Warning System ◽  
Volcanic Eruptions ◽  
Heavy Rain ◽  
Integrated System ◽  
Pyroclastic Flows ◽  
Special Issue ◽  
Merapi Volcano ◽  
2014 Eruption

Volcanic eruptions induce often widely dispersed, multimodal flows such as volcanic ash, pyroclastics, layers, and lava. Lahars triggered by heavy rain may extend far beyond ash deposits. Indonesia, which has 127 volcanoes along its archipelago, is at high risk for such disasters. The 2010 Merapi volcano eruption, for example, generated pyroclastic flows up to 17 km from the summit along the Gendol River, killing over 300 residents. The February 13, 2014, eruption of the Kelud volcano produced a gigantic ash plume over 17 km high, dispersing tehpra widely over Java Island. Ash falls and dispersion closed 7 airports and caused many flights to be cancelled. Volcanoes in Japan have recently become active, with the 2014 phreatic eruption at the Ontake volcano leaving 63 hikers dead or missing. The eruption of the Kuchinoerabujima volcano on May 29, 2015, forced all island residents to be evacuated. All of these events undeerscore how underedeveloped Japan’s early warning alert levels remain. The Sakurajima volcano, currently Japan’s most active, maintained high activity in the first half of 2015. Ash from Janaury 2015, for example, was moved down the volcano’s slopes by extremely heavy rain in June and July, accumulating as thick sediment near villages. Regarding such situations of volcano countries, we will develop an integrated system to mitigate many kinds of disasters which are generated by volcanic eruptions and extended by rain fall and wind, based on scientific knowledge. We are developing an integrated warning system to be used by local and national governments to mitigate volcanic and sediment disasters. We are also creating measure against volcanic ash for airlines. This special issue summarizes basic scientific knowledge and technology on the present warning system to be used in the integrated system for decision-making.

scholarly journals The Cuitzeo granitic xenolith: evidence of an Early Miocene magma plumbing system in central Mexico

2021 ◽  
Vol 38 (1) ◽  
pp. 29-42
Author(s):  
María del Sol Hernández-Bernal ◽  
Pedro Corona-Chávez ◽  
Noemí Trujillo-Hernández ◽  
Consuelo Macías-Romo ◽  
Dante Jaime Morán-Zenteno ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Volcanic Eruptions ◽  
Isotopic Analysis ◽  
Early Miocene ◽  
Central Mexico ◽  
Plumbing System ◽  
Magma Plumbing System ◽  
Isotopic Signatures ◽  
Isotopic Analyses ◽  
Magma Plumbing

Relevant data on the structure and composition of the crystalline basement in Central México can be found by means of plutonic, metamorphic, and sedimentary xenoliths transported by Neogene and Quaternary volcanic eruptions within the Trans-Mexican Volcanic Belt (TMVB). We present detailed major oxide and trace elements concentrations, isotopic analysis and thermobarometric estimations for a granitic xenolith found in an Early Miocene ignimbrite in Cuitzeo Lake, Michoacán. The xenolith is a calc-alkaline quartz-plagioclase-K-feldspar-biotite-amphibole granite-monzogranite with 73.7 wt.% SiO2. Trace element and isotopic signatures are compatible with a volcanic arc signature. According to amphibole-plagioclase pairs and Ti-in-zircon thermobarometry, the studied xenolith suggests that the granitic system crystallized between 655–737 °C and 1.3–1.9 kbar. U-Pb isotopic analyses of zircon grains from this rock have provided a concordia age of 20.76 ± 0.11 Ma. The presence of granitic xenoliths in Quaternary eruptions produced by the TMVB are not rare. However, this is the first zircon age of a Miocene granitic rock showing evidence of the shallow plutonic counterpart of the magma plumbing system of the Early Miocene (~23 to ~16 Ma) Mil Cumbres - Angangueo voluminous, andesitic-dacitic-rhyolitic episode. Implications for faulting, erosion, and Miocene-Pliocene ignimbrite emplacement in Cuitzeo region are also discussed.

scholarly journals The dynamics of dual-magma-chamber system during volcanic eruptions inferred from physical modeling

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Tomofumi Kozono
Keyword(s):  
Analytical Solution ◽  
Magma Chamber ◽  
Volcanic Eruptions ◽  
Chamber Pressure ◽  
Deformation Pattern ◽  
Chamber System ◽  
Plumbing System ◽  
Magma Chambers ◽  
Magma Flow ◽  
Magma Plumbing System

AbstractA magma plumbing system with dual magma chambers beneath active volcanoes is commonly observed through petrological and geophysical measurements. This paper developed a physical model for the dynamics of a dual-magma-chamber system during volcanic eruptions. The model consists of the plumbing system where two elastically deformable magma chambers are connected in series with non-deformable conduits. Based on this model, we obtained an analytical solution that describes temporal changes in pressures at the two chambers accompanied by the eruption. The analytical solution showed that the feature of the chamber pressure changes is mainly controlled by two non-dimensional numbers $$C'$$ C ′ and $$\Omega '$$ Ω ′ . Here, $$C'$$ C ′ is the ratio of the parameter controlling the magnitude of pressure change in the shallower chamber to that in the deeper chamber, and $$\Omega '$$ Ω ′ is the ratio of conduit’s conductivity (inverse of resistivity to magma flow) between the shallower chamber and the surface to that between the chambers. For smaller $$C'$$ C ′ and $$\Omega '$$ Ω ′ , the shallower chamber’s pressure is kept constant during the decrease in the pressure at the deeper chamber in the initial phase of the eruption. This corresponds to a deformation pattern commonly observed in some eruptions, in which the deflation of the deeper chamber was predominant. The estimation of $$C'$$ C ′ and $$\Omega '$$ Ω ′ based on the parameters related to magma properties and geometries of the chambers and the conduits revealed that the smaller $$C'$$ C ′ and $$\Omega '$$ Ω ′ conditions are satisfied under realistic magmatic and geological parameters. This indicates that the magma dynamics in the dual-chamber system generally cause the dominance of the deeper chamber’s deflation.

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