scholarly journals RESEARCH FOCUS: Volcanic eruptions: From ionosphere to the plumbing system

Geology ◽  
2018 ◽  
Vol 46 (10) ◽  
pp. 927-928 ◽  
Author(s):  
Chiara Maria Petrone
Keyword(s):  
Volcanic Eruptions ◽  
Plumbing System ◽  
Research Focus

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.

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 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 (>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 (>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 (>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.

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.

Feelings of Figures in Novel Notes Juang Fiersa Besari (Personality Ludwig Klages)

2020 ◽  
Vol 8 (3) ◽  
pp. 13
Author(s):  
Faridatus Soleha
Keyword(s):  
Qualitative Approach ◽  
Personality Structure ◽  
Personality Theory ◽  
The Novel ◽  
Research Focus ◽  
The Third ◽  
Analyze Data

This study aims to describe the feelings of the characters in the novel Juang Notes by Fiersa Bersari and researchers analyze using personality theory originated by Ludwig Klages by focusing his study on the personality structure of feelings. Feeling is a process of someone accepting or rejecting something in life. This study uses a qualitative approach by using library techniques to obtain data that will produce a description of the words or sentences in the observed study. In the analysis of this research using the hermeutics technique, in the hermeutics technique there are several stages, namely reading the research object in this study in the form of a fighting journal, the second gives a mark on the data that has been obtained from the reading results, the third provides code or coding on the data that has been found, and the fourth is to analyze data that has been obtained from the object of research in accordance with the specified research focus. Novel Notes Juang by Fiersa Besari is a novel that can be used as an inspiration for readers in living life. Based on the results of the study it was found that in the Fighting Notes novel there is a feeling that is divided into inner activities and the level of clarity, inner activities in the novel in the form of fear and guilt while viewed from the level of clarity in the form of happiness, sadness and longing.

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

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