Determining tephra fall deposit thickness in sedimentary record from magnetic susceptibility curve: Example of four Ethiopian tephras

2004 ◽  
Vol 5 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. Touchard ◽  
P. Rochette
Keyword(s):  
Magnetic Susceptibility ◽  
Fall Deposit ◽  
Sedimentary Record ◽  
Tephra Fall ◽  
Deposit Thickness ◽  
Susceptibility Curve ◽  
Magnetic Susceptibility Curve

scholarly journals The Orange Tuff: a Late Pleistocene tephra-fall deposit emplaced by a VEI 5 silicic Plinian eruption in West Java, Indonesia

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Christopher J. Harpel ◽  
Kushendratno ◽  
James Stimac ◽  
Cecilia F. Avendaño Rodríguez de Harpel ◽  
Sofyan Primulyana
Keyword(s):  
Late Pleistocene ◽  
Plinian Eruption ◽  
Fall Deposit ◽  
West Java ◽  
Tephra Fall

Chemical variations of tephra-fall deposit leachates for three eruptions from Popocatépetl volcano

2002 ◽  
Vol 113 (1-2) ◽  
pp. 61-80 ◽  
Author(s):  
M.A. Armienta ◽  
S. De la Cruz-Reyna ◽  
O. Morton ◽  
O. Cruz ◽  
N. Ceniceros
Keyword(s):  
Fall Deposit ◽  
Tephra Fall ◽  
Popocatépetl Volcano ◽  
Popocatepetl Volcano

scholarly journals A simple semi-empirical approach to model thickness of ash-deposits for different eruption scenarios

2010 ◽  
Vol 10 (11) ◽  
pp. 2241-2257 ◽  
Author(s):  
A. O. González-Mellado ◽  
S. De la Cruz-Reyna
Keyword(s):  
Active Volcano ◽  
Fall Deposit ◽  
Unknown Parameters ◽  
Graphic Interface ◽  
Deposit Thickness ◽  
Ash Fall ◽  
Accurate Perception ◽  
User Friendly ◽  
Semi Empirical ◽  
The Impact

Abstract. The impact of ash-fall on people, buildings, crops, water resources, and infrastructure depends on several factors such as the thickness of the deposits, grain size distribution and others. Preparedness against tephra falls over large regions around an active volcano requires an understanding of all processes controlling those factors, and a working model capable of predicting at least some of them. However, the complexity of tephra dispersion and sedimentation makes the search of an integral solution an almost unapproachable problem in the absence of highly efficient computing facilities due to the large number of equations and unknown parameters that control the process. An alternative attempt is made here to address the problem of modeling the thickness of ash deposits as a primary impact factor that can be easily communicated to the public and decision-makers. We develop a semi-empirical inversion model to estimate the thickness of non-compacted deposits produced by an explosive eruption around a volcano in the distance range 4–150 km from the eruptive source. The model was elaborated from the analysis of the geometric distribution of deposit thickness of 14 world-wide well-documented eruptions. The model was initially developed to depict deposits of potential eruptions of Popocatépetl and Colima volcanoes in México, but it can be applied to any volcano. It has been designed to provide planners and Civil Protection authorities of an accurate perception of the ash-fall deposit thickness that may be expected for different eruption scenarios. The model needs to be fed with a few easy-to-obtain parameters, namely, height of the eruptive column, duration of the explosive phase, and wind speed and direction, and its simplicity allows it to run in any platform, including a personal computers and even a notebook. The results may be represented as tables, two dimensional thickness-distance plots, or isopach maps using any available graphic interface. The model has been tested, with available data from some recent eruptions in México, and permits to generate ash-fall deposit scenarios from new situations, or to recreate past situations, or to superimpose scenarios from eruptions of other volcanoes. The results may be displayed as thickness vs. distance plots, or as deposit-thickness scenarios superimposed on a regional map by means of a visual computer simulator based on a user-friendly built-in computer graphic interface.

scholarly journals Eruptive activity of Planchón-Peteroa volcano for period 2010-2011, Southern Andean Volcanic Zone, Chile

2015 ◽  
Vol 43 (1) ◽  
pp. 20 ◽  
Author(s):  
Felipe Aguilera ◽  
Oscar Benavente ◽  
Francisco Gutiérrez ◽  
Jorge Romero ◽  
Ornella Saltori ◽  
...  
Keyword(s):  
Fall Deposit ◽  
Tephra Fall ◽  
Crater Lakes ◽  
Active Crater ◽  
Maule Earthquake ◽  
Magmatic Reservoir ◽  
Eruptive Period ◽  
Main Component ◽  
Thickness Variable ◽  
Fall Deposits

Planchón-Peteroa volcano started a renewed eruptive period between January 2010 and July 2011. This eruptive period was characterized by the occurrence of 4 explosive eruptive phases, dominated by low-intensity phreatic activity, which produced almost permanent gas/steam columns (200-800 m height over the active crater). Those columns presented frequently scarce ash, and were interrupted by phreatic explosions that produced ash columns 1,000-3,000 m height in the more intense periods. Eruptive plumes were transported in several directions (NW, N, NE, E and SE), but more than half of the time the plume axis was 130-150° E, and reached a distance up to 638 km from the active crater. Tephra fall deposits identified in the NW, N, NE, E and SE flanks covered an area of 1,265 km2, thickness variable from 4 m (SE border of active crater) to ~0.5 cm 36.8 km SE and ~8 km NW from active crater, respectively, corresponding to a minimum volume of 0.0088 km3. Tephra fall deposit is exclusively constituted of no juvenile fragments including: lithics fragments as main component, quartz and plagioclase crystals, some oxidized lithics, and occasional presence of Fe oxide, and less frequently Cu minerals, as single fragments. We present new field-based measurements data of the geochemistry of gas/water from fumaroles and acid crater lakes, and fall deposit analysis, that integrated with the eruptive record and GOES satellite data, suggests that the eruptive period 2010-2011 has been related to an increasing of heat and mass transfer from hydrothermal-magmatic reservoirs, which would have been favoured by the formation and/or reactivation of cracks after 8.8 Mw Maule earthquake in February 2010. This process also allowed the ascent of fluids from a shallow hydrothermal source, dominated by reduced species as H2S and CH4, during the entire eruptive period, and the release of more oxidizing fluids from a deep magmatic reservoir, dominated by acid species as SO2, HCl and HF, increasing strongly after the end of the eruptive period, probably since October 2011. The eruptive period was scored with a magnitude of 3.36, corresponding to a VEI 1-2.

THE OPENING SUBPLINIAN PHASE OF THE HEKLA 1991 ERUPTION: PROPERTIES OF THE TEPHRA FALL DEPOSIT

2017 ◽  
Author(s):  
J. Gudnason ◽  
◽  
T. Thordarson ◽  
B.F. Houghton ◽  
G. Larsen
Keyword(s):  
Fall Deposit ◽  
Tephra Fall

scholarly journals The Singularity Paramagnetic Peak of Bi0.3Sb1.7Te3 with p-type Surface State

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Shiu-Ming Huang ◽  
Pin-Cing Wang ◽  
Pin-Cyuan Chen ◽  
Jai-Long Hong ◽  
Cheng-Maw Cheng ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Fermi Level ◽  
Single Crystal ◽  
Temperature Variation ◽  
Surface State ◽  
Dirac Point ◽  
Magnetization Measurement ◽  
Spin Texture ◽  
P Type ◽  
Susceptibility Curve

AbstractThe magnetization measurement was performed in the Bi0.3Sb1.7Te3 single crystal. The magnetic susceptibility revealed a paramagnetic peak independent of the experimental temperature variation. It is speculated to be originated from the free-aligned spin texture at the Dirac point. The ARPES reveals that the Fermi level lies below the Dirac point. The Fermi wavevector extracted from the de Haas–van Alphen oscillation is consistent with the energy dispersion in the ARPES. Our experimental results support that the observed paramagnetic peak in the susceptibility curve does not originate from the free-aligned spin texture at the Dirac point.

INTERPRETING A HEAVILY BIOTURBATED TEPHRA FALL DEPOSIT AT KINGS BOWL, IDAHO

2016 ◽  
Author(s):  
Allison Trcka ◽  
◽  
Erin Sandmeyer ◽  
Shannon Kobs Nawotniak
Keyword(s):  
Fall Deposit ◽  
Tephra Fall

The opening subplinian phase of the Hekla 1991 eruption: properties of the tephra fall deposit

2017 ◽  
Vol 79 (5) ◽  
Author(s):  
Jonas Gudnason ◽  
Thor Thordarson ◽  
Bruce F. Houghton ◽  
Gudrun Larsen
Keyword(s):  
Fall Deposit ◽  
Tephra Fall
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