AshCalc–a new tool for the comparison of the exponential, power-law and Weibull models of tephra deposition

Daggitt, Matthew L.; Mather, Tamsin A.; Pyle, David M.; Page, Stephen

doi:10.1186/2191-5040-3-7

Cited by 47 publications

(34 citation statements)

References 14 publications

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“…The proportion of these ingredients may vary between eruptions however volume of air-borne tephra definitely constitutes a very significant part of the total tephra volume. Estimates of this part are normally based on field measurements of tephra thickness and grain-size, which are then used in sophisticated calculations and models (e.g., Bonadonna and Costa, 2012;Costa et al, 2012Costa et al, , 2014Johnston et al, 2012;Daggitt et al, 2014). Tephra volumes are also used for calculating the amount of climate-affecting volatiles released into the atmosphere (e.g., Metzner et al, 2014).…”

Section: Eruption Sizes and Tephra Dispersalmentioning

confidence: 99%

Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions

2015

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This review is intended to highlight recent exciting advances in the study of distal (>100 km from the source) tephra and cryptotephra deposits and their potential application for volcanology. Geochemical correlations of tephra between proximal and distal locations have extended the geographical distribution of tephra over tens of millions square kilometers. Such correlations embark on the potential to reappraise volume and magnitude estimates of known eruptions. Cryptotephra investigations in marine, lake, and ice-core records also give rise to continuous chronicles of large explosive eruptions many of which were hitherto unknown. Tephra preservation within distal ice sheets and varved lake sediments permit precise dating of parent eruptions and provide new insight into the frequency of eruptions. Recent advances in analytical methods permit an examination of magmatic processes and the evolution of the whole volcanic belts at distances of hundreds and thousands of kilometers from source. Distal tephrochronology has much to offer volcanology and has the potential to significantly contribute to our understanding of sizes, recurrence intervals and geochemical make-up of the large explosive eruptions.

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Section: Eruption Sizes and Tephra Dispersalmentioning

confidence: 99%

Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions

2015

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“…4 Total discharged mass estimation using the exponential method (Pyle 1989). AshCalc (Daggitt et al 2014) was used for the calculation. Five multi-segmented regression lines are shown as different colors integration method (Takarada et al 2001), resulting in a total value of 1.86 × 10 6 t (Fig.…”

Section: Comparison With the 1979 Ontake Eruptionmentioning

confidence: 99%

“…4). The AshCalc Python tool (Daggitt et al 2014) was used to draw five multi-segmented regression lines. The calculated total discharged mass was 8.9 × 10 5 t, which is slightly less but relatively similar to that calculated using the segment integration method (1.18 × 10 6 t).…”

Section: Isopleth Mass Distribution Map and Estimation Of Total Dischmentioning

confidence: 99%

Estimation of total discharged mass from the phreatic eruption of Ontake Volcano, central Japan, on September 27, 2014

et al. 2016

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The total mass discharged by the phreatic eruption of Ontake Volcano, central Japan, on September 27, 2014, was estimated using several methods. The estimated discharged mass was 1.2 × 10 6 t (segment integration method), 8.9 × 10 5 t (Pyle's exponential method), and varied from 8.6 × 10 3 to 2.5 × 10 6 t (Hayakawa's single isopach method). The segment integration and Pyle's exponential methods gave similar values. The single isopach method, however, gave a wide range of results depending on which contour was used. Therefore, the total discharged mass of the 2014 eruption is estimated at between 8.9 × 10 5 and 1.2 × 10 6 t. More than 90 % of the total mass accumulated within the proximal area. This shows how important it is to include a proximal area field survey for the total mass estimation of phreatic eruptions. A detailed isopleth mass distribution map was prepared covering as far as 85 km from the source. The main ash-fall dispersal was ENE in the proximal and medial areas and E in the distal area. The secondary distribution lobes also extended to the S and NW proximally, reflecting the effects of elutriation ash and surge deposits from pyroclastic density currents during the phreatic eruption. The total discharged mass of the 1979 phreatic eruption was also calculated for comparison. The resulting volume of 1.9 × 10 6 t (using the segment integration method) indicates that it was about 1.6-2.1 times larger than the 2014 eruption. The estimated average discharged mass flux rate of the 2014 eruption was 1.7 × 10 8 kg/h and for the 1979 eruption was 1.0 × 10 8 kg/h. One of the possible reasons for the higher flux rate of the 2014 eruption is the occurrence of pyroclastic density currents at the summit area.

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“…Here, field measurements are fit using least-square regressions. Little is discussed here regarding the advantages and limitations of the different methods, as extensive reviews can be found in González-Mellado & Cruz-Reyna (2010), Bonadonna & Costa (2012) and Daggitt et al (2014).…”

Section: Tephra Volumementioning

confidence: 99%

“…We use here the simplification proposed by Daggitt et al (2014), where θ is expressed as a function of λ and k as:…”

Section: Bonadonna and Costa 2012mentioning

confidence: 99%

TError: towards a better quantification of the uncertainty propagated during the characterization of tephra deposits

Biass¹,

Bagheri²,

Aeberhard³

et al. 2013

SIV

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We present TError, a Matlab package designed to quantify systematically the uncertainty associated with the characterization of tephra deposits, in which the most commonly used methods to quantify eruption source parameters are implemented. Inputs of the code are a range of field-based, model-based and empirical parameters (i.e., clast diameter, crosswind and downwind ranges, thickness measurement, area of isopach contours, bulk deposit density, empirical constants and wind speed), for which the user defines an uncertainty and an associated distribution. The TError package contains two main functions. The first function deterministically varies one input parameter at a time and quantifies the sensitivity of each Eruption Source Parameter (ESP; i.e., plume height, erupted volume, mass eruption rate) to the variability of input parameters. The second function propagates input parameters as stochastic distributions of noise through all ESPs. The resulting distributions can then be used to express the uncertainty of physical parameters of explosive eruptions in a systematic way. For both functions, comprehensive reports and sets of figures assist the user in the interpretation of the results. As an example, the TError package was applied to Layer 5 of Cotopaxi volcano. Using the median, the 2 nd percentile and the 98 th percentile as central value, lower bound and upper bound respectively, a new quantification of the ESP suggests a plume height of 30 ± 1 km a.s.l, a mass eruption rate of 1.8 citation:Biass, S., G. Bagheri, W. H. Aeberhard, C. Bonadonna (2014) TError: towards a better quantification of the uncertainty propagated during the characterization of tephra deposits, Statistics in Volcanology 1.2 : 1 − 27.

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AshCalc–a new tool for the comparison of the exponential, power-law and Weibull models of tephra deposition

Cited by 47 publications

References 14 publications

Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions

Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions

Estimation of total discharged mass from the phreatic eruption of Ontake Volcano, central Japan, on September 27, 2014

TError: towards a better quantification of the uncertainty propagated during the characterization of tephra deposits

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