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R Saucedo - One of the best experts on this subject based on the ideXlab platform.
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Storage conditions and magma processes triggering the 1818 CE Plinian Eruption of Volcán de Colima
Journal of Volcanology and Geothermal Research, 2017Co-Authors: José Luis Macías, R Saucedo, Giovanni Sosa-ceballos, José Luis Arce, James E. Gardner, Gabriel Valdez-morenoAbstract:Abstract Volcan de Colima has an eruptive history punctuated with explosive Plinian Eruptions followed by long periods of effusive events. Both of the best documented Plinian Eruptions, which occurred in 1818 CE and 1913 CE, emitted andesitic magma (~ 58 wt% SiO 2 ) that contains Pl > Opx > Cpx ≫ Amph + Fe-Ti oxides + Ap ± resorbed Ol, whereas effusive magmas from the 1819–1868 and 1962–2015 periods are particularly scarce in amphibole, and are slightly more silicic (59–61 wt% SiO 2 ). Pumice from the 1818 and 1913 deposits contain three groups of amphibole with different abundance, texture and composition. Composition is the most distinctive between them; the first group consists of crystals with high Al IV (1.84–2.32), the second group of amphiboles is less abundant in Al IV (1.45–1.76) and the third has low Al IV (1.29–1.39). In contrast, amphibole from two Colima prehistoric lavas can only be grouped as medium Al IV (1.45–1.76). A set of hydrothermal experiments were carried out using a 1818 natural sample to investigate amphibole compositional variability with changes in pressure and temperature. Two groups of amphibole found in the Plinian deposits can be reproduced experimentally between 875 and 900 °C and 150–200 MPa. Another type of amphibole could not be equilibrated in the 1818 explosive Colima magma and their origin can be attributed to mixing with more mafic magmas. We found that amphibole abundance is greater in explosive events and that mafic inherited amphiboles can only be found in Colima Plinian deposits. When the influx of mafic magma is large or frequent enough, and they mix with more silicic Colima magma, then explosive events are more likely. If mafic melts cannot mix with the resident magmas or just pond and heat the reservoir, regardless of location in the plumbing system, then magmas can decompress more slowly and amphibole will have time to completely react out.
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tephra fallout hazard assessment for a Plinian Eruption scenario at volcan de colima mexico
Journal of Volcanology and Geothermal Research, 2011Co-Authors: Rosanna Bonasia, Lucia Capra, Antonio Costa, G Macedonio, R SaucedoAbstract:Abstract Volcanic ash fallout associated with renewal of explosive activity at Colima, represents a serious threat to the surrounding urbanized area. Here we assess the tephra fallout hazard associated with a Plinian Eruption scenario. The eruptive history of Volcan de Colima shows that Plinian Eruptions occur approximately every 100 years and the last Eruption, the 1913, represents the largest historic Eruption of this volcano. We used the last Eruption as a reference to discuss volcanic hazard and risk scenarios connected with ash fallout. Tephra fallout deposits are modeled using HAZMAP, a model based on a semi-analytical solution of the advection–diffusion–sedimentation equation for volcanic particles. Based on a statistical study of wind profiles at Colima region, we first reconstructed ash loading maps and then computed ground load probability maps for different seasons. The obtained results show that a Plinian eruptive scenario at Volcan de Colima, could seriously damage more than 10 small towns and ranches, and potentially affect big cities located at tens of kilometers from the eruptive center. The probability maps obtained are aimed to give support to the risk mitigation strategies.
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eyewitness stratigraphy chemistry and eruptive dynamics of the 1913 Plinian Eruption of volcan de colima mexico
Journal of Volcanology and Geothermal Research, 2010Co-Authors: R Saucedo, José Luis Macías, Jean-christophe Komorowski, James E. Gardner, J L Arce, J C Gavilanes, Gabriel ValdezmorenoAbstract:Abstract Based on the stratigraphic record of the deposits, analysis of previous works, historic archives, and eyewitness accounts the 1913 Eruption of Volcan de Colima was reconstructed. The Eruption started in 17 January and peaked in 20 January, 1913. It occurred in three main phases: 1) An opening phase with the generation of Merapi-type pyroclastic flows (units F1, F2, F3) and a pyroclastic surge (S1), 2) A vent-clearing phase with strong explosions that produced Vulcanian-Soufriere-type pyroclastic flows (F4) and a pyroclastic surge (S2) which destroyed the summit dome decompressing the magma system, and 3) a Plinian phase with the establishment of a ∼ 23 km high column dispersing a fallout (C1) to the NE followed by the collapse of the column that generated a pyroclastic surge (S3) and 15-km long pumice-rich pyroclastic flows (F5). After the Eruption, remobilization of the pyroclastic material generated lahars in main gullies around the crater. Fallout C1 blanketed an area of ∼ 191,318 km2 covering the cities of Guzman, Guadalajara, and Saltillo (Coahuila) located at 725 km from the source. It had a volume of 1.4 km3 (0.57 km3 DRE = Dense Rock Equivalent). The total volume of pyroclastic flow and surge deposits was 0.26 km3 (0.07 km3 DRE) giving a total volume of the Eruption of 1.66 km3 (0.64 km3 DRE). The Plinian column lasted 4.6 h with a total mass of 1.5 × 1012 kg and a mass Eruption rate of 9.02 × 107 kg/s. The column height and the ejected magma volume indicate that the 1913 Eruption had a VEI = 5 being the largest event in the historical record of Colima Volcano. Juvenile scoria and pumice consisted of Pl > Opx > Cpx > Hbl + accessory titanomagnetite + Ap and Ol with reaction rims. Chemistry of juvenile scoria and pumice samples is andesitic very homogeneous (58.3 ± 0.5 wt.% SiO2) and similar to the 1818 juvenile products (58.9 ± 0.2 wt.% SiO2). The presence of banded scoria, olivine phenocrysts with reaction rims, and trace element variations strongly suggest that the 1913 Eruption was caused by a magma mixing event.
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A 550-year-old Plinian Eruption at El Chichón Volcano, Chiapas, Mexico: Explosive volcanism linked to reheating of the magma reservoir
Journal of Geophysical Research, 2003Co-Authors: José Luis Macías, J. M. Espíndola, R Saucedo, José Luis Arce, J. C. Mora, Piero ManettiAbstract:[1] Some 550 years ago (1320–1433 A.D.), a powerful Plinian Eruption at El Chichon Volcano in southern Mexico produced a widespread pumice fall deposit. We subdivided the deposit into three parts on the basis of structural and textural characteristics, pumice lithology and density, granulometry, and petrologic-geochemical attributes. The deposit covers an area of 1500 km2 within the 1-cm isopach and has a minimum estimated bulk volume of 2.8 km3 (1.1 km3 dense rock equivalent (DRE)); its eruptive column reached an altitude of ∼31 km. Consideration of field evidence, the presence and nature of mafic enclaves, and chemical data strongly suggest that the 550 year B.P. Eruption is linked with the intrusion of a high-temperature basaltic magma into preexisting but stagnated trachyandesitic magma beneath El Chichon. Thorough mixing of the two magmas produced a compositionally uniform hybrid trachyandesite magma (average SiO2 55.3 wt %), which subsequently underwent crystal growth and gas exsolution, ultimately overpressurizing the zoned magmatic system to erupt explosively. On the basis of El Chichon's known eruptive history, the intrusion-mixing event occurred sometime after the 900 year B.P. Eruption. The hybrid magma had a preEruption temperature of 820–830°C and was water undersaturated (5–6 wt % H2O) at pressures of ∼2–2.5 kbar.
José Luis Macías - One of the best experts on this subject based on the ideXlab platform.
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Storage conditions and magma processes triggering the 1818 CE Plinian Eruption of Volcán de Colima
Journal of Volcanology and Geothermal Research, 2017Co-Authors: José Luis Macías, R Saucedo, Giovanni Sosa-ceballos, José Luis Arce, James E. Gardner, Gabriel Valdez-morenoAbstract:Abstract Volcan de Colima has an eruptive history punctuated with explosive Plinian Eruptions followed by long periods of effusive events. Both of the best documented Plinian Eruptions, which occurred in 1818 CE and 1913 CE, emitted andesitic magma (~ 58 wt% SiO 2 ) that contains Pl > Opx > Cpx ≫ Amph + Fe-Ti oxides + Ap ± resorbed Ol, whereas effusive magmas from the 1819–1868 and 1962–2015 periods are particularly scarce in amphibole, and are slightly more silicic (59–61 wt% SiO 2 ). Pumice from the 1818 and 1913 deposits contain three groups of amphibole with different abundance, texture and composition. Composition is the most distinctive between them; the first group consists of crystals with high Al IV (1.84–2.32), the second group of amphiboles is less abundant in Al IV (1.45–1.76) and the third has low Al IV (1.29–1.39). In contrast, amphibole from two Colima prehistoric lavas can only be grouped as medium Al IV (1.45–1.76). A set of hydrothermal experiments were carried out using a 1818 natural sample to investigate amphibole compositional variability with changes in pressure and temperature. Two groups of amphibole found in the Plinian deposits can be reproduced experimentally between 875 and 900 °C and 150–200 MPa. Another type of amphibole could not be equilibrated in the 1818 explosive Colima magma and their origin can be attributed to mixing with more mafic magmas. We found that amphibole abundance is greater in explosive events and that mafic inherited amphiboles can only be found in Colima Plinian deposits. When the influx of mafic magma is large or frequent enough, and they mix with more silicic Colima magma, then explosive events are more likely. If mafic melts cannot mix with the resident magmas or just pond and heat the reservoir, regardless of location in the plumbing system, then magmas can decompress more slowly and amphibole will have time to completely react out.
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Stratigraphy, chemistry, and eruptive dynamics of the 12.4 ka Plinian Eruption of Apoyeque volcano, Managua, Nicaragua
Bulletin of Volcanology, 2014Co-Authors: Denis Ramón Avellán, José Luis Macías, Giovanni Sosa-ceballos, Gema VelásquezAbstract:Apoyeque volcano, located 9 km northwest of Managua city, erupted explosively at 12.4 ka. The Plinian Eruption deposited a widespread pumice fall deposit known as the Upper Apoyeque Tephra (UAq). The UAq is massive, reversely graded, and consists of white juvenile pumice (~78 vol.%), a variety of cognate lithics and accidental altered lithics. The whole-rock pumice composition is rhyodacitic (SiO2 = 66.9–68.5 wt.%) with a mineral paragenesis of plagioclase, orthopyroxene, clinopyroxene, amphibole, titanomagnetite, and ilmenite in a rhyolitic glass groundmass (SiO2 = 74.4 ± 0.6 wt.%). The deposit’s dispersal axis is to the south, with the deposit covering a minimum area of 877 km2 within the 50 cm isopach and has a total volume of 3 km3 (dense rock equivalent, 1.15 km3). The Eruption column reached a maximum height of ca.28 km. The Eruption ejected a total mass of 3 × 1012 kg at an average rate of 2 × 108 kg/s, and based on available models, we infer duration of almost 4 h. Petrographic and geochemical characteristics suggest that the Eruption was triggered by magma mixing.
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the 31 ka rhyolitic Plinian to sub Plinian Eruption of tlaloc volcano sierra nevada central mexico
Journal of Volcanology and Geothermal Research, 2013Co-Authors: H Rueda, José Luis Macías, James E. Gardner, J L Arce, Paul W LayerAbstract:Abstract Tlaloc is a late Pleistocene stratovolcano located NE of Mexico City. It is the northernmost volcano of the N–S Sierra Nevada Volcanic Range, which consists from north to south of Tlaloc, Telapon, Iztaccihuatl, and Popocatepetl volcanoes. Tlaloc has always been considered the oldest (and extinct) volcano of the Sierra Nevada Volcanic Range. Recent field data revealed that Tlaloc was very active during late Pleistocene through a series of explosive Eruptions. One of these Eruptions produced the Multilayered White Pumice (MWP) a rhyolitic pyroclastic sequence. The Eruption began with a 24-km high Plinian column MWP-F1 that was dispersed to the NE by prevailing winds. It was interrupted by fountaining of the column with the generation of a pyroclastic density current that emplaced MWP-S1 layer. Then, followed five unstable sub-Plinian columns (MWP-F2 to F6) that reached altitudes between 16 and 19 km. Fall deposits as a whole are 1 m thick at 12 km from the vent, cover a minimum area of 577 km2 for a total volume of 4.68 km3 (DRE 1.58 km3). The Eruption ejected a total mass of 3.45 × 1012 kg at different mass discharges. The last sub-Plinian column (MWP-F6) collapsed and produced dense pyroclastic density currents that deposited pumiceous pyroclastic flows (MWP-PF) following main ravines to the north and east of the vent. These density currents filled gullies with 23 m-thick deposits at a distance of 12 km from the vent totaling a minimum DRE volume of 0.2 km3. Pyroclastic flow deposits charred tree trunks that yielded an age of 31,490 + 1995/− 1595 yr B.P. that closely date the age of the Eruption. Rain during this phase of the Eruption generated syn-eruptive lahars (MWP-DF). Post-eruptive lahars (MWP-ED) finally swept the volcano flanks. The MWP deposits consist of abundant white pumice (up to 96 vol.%), rare gray pumice, cognate lithics, accidental altered lithics, xenocrysts. White and gray pumice clasts contain phenocrysts of quartz, plagioclase, sanidine, biotite, rare Fe–Ti oxides, monazite, zircon and apatite. Xenocrysts are represented by plagioclase, microcline, orthoclase and quartz likely coming from a deeper plutonic body. Both pumices have a rhyolitic composition (74.98 ± 1 wt.% SiO2 in water free basis) representing one of the most acidic products of Tlaloc and the entire Sierra Nevada Volcanic Range. The rhyolitic liquid was likely extracted from a mush-like plutonic body reaching the minimum predicted vesicularity values for Plinian fragmentation for which the triggering mechanism of the MWP Eruption is attributed to the high viscosity of the magma that provoked overpressure of the magmatic system. The parameters studied suggest that Eruption behavior evolved from Plinian to sub-Plinian eruptive columns over time due to conduit dynamics rather than variations in magma properties of the MWP products.
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reconstruction of the sibinal pumice an andesitic Plinian Eruption at tacana volcanic complex mexico guatemala
Journal of Volcanology and Geothermal Research, 2012Co-Authors: J L Arce, José Luis Macías, James E. Gardner, E RangelAbstract:Abstract The Tacana Volcanic Complex, located on the Mexico–Guatemala border, has had numerous small historical explosions, the latest being a phreatic explosion in 1986. The stratigraphic record, however, suggests that much more voluminous Eruptions have occurred in the past. Here, we document one such Eruption, the Sibinal Pumice deposit, which occurred ca. 23,540 years B.P. The deposit consists of two pumice-rich units: 1) a lower stratified member (SM) that consists of at least seven, normally graded fall layers, interbedded with pyroclastic wet surge layers; and 2) an upper massive member (MM), made up of a single fall deposit. Both members can reach up to 2.5 m in thickness and are separated by a single massive, indurated, yellowish, pumice-rich reworked layer. SM was dispersed to the northeast (N70°E), with its 6-cm isopach covering an area of 275 km2, whereas MM was dispersed to the north (N22°E), with its 70-cm isopach covering an area of ca. 330 km2. Yellow, vesicular pumice fragments, light-gray lithics, and hydrothermally altered (red and black) dense lithics are abundant in both members, although altered lithics are more abundant at the base of each, reaching 15 vol.%. Pumice compositions range from basaltic to andesitic (48–61 wt.% SiO2, anhydrous basis), but are highly altered. They contain plagioclase (andesine–labradorite), augite, hypersthene, Fe–Ti oxides, and rare amphibole. No compositional or mineralogical differences occur between the units indicating a common magma source during the same Eruption. The Sibinal Pumice Eruption started with a weak, pulsating column that reached at most 19 km in height, ejecting 2.9 km3 of tephra (1.1 km3 DRE) at an average mass discharge rate of 4.7 × 107 kg/s, with repeated hydromagmatic explosions that generated wet surges down the slopes of the volcano. The Eruption ceased for a while during which rainfall generated a widespread lahar that eroded the top of SM. The Eruption began anew with a sustained and stable Plinian column that ejected 4.6 km3 (1.9 km3 DRE) of tephra at a mass discharge rate of 8.1 × 107 kg/s. The lack of any compositional differences in the magma suggests that the change in eruptive style was driven by influxes of external water provoking hydromagmatic explosions that cleared the conduit, then, the system changed to dry system and the Eruption style changed from pulsating to stable Plinian. As the conduit became wider, the mass discharge rate also increased.
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eyewitness stratigraphy chemistry and eruptive dynamics of the 1913 Plinian Eruption of volcan de colima mexico
Journal of Volcanology and Geothermal Research, 2010Co-Authors: R Saucedo, José Luis Macías, Jean-christophe Komorowski, James E. Gardner, J L Arce, J C Gavilanes, Gabriel ValdezmorenoAbstract:Abstract Based on the stratigraphic record of the deposits, analysis of previous works, historic archives, and eyewitness accounts the 1913 Eruption of Volcan de Colima was reconstructed. The Eruption started in 17 January and peaked in 20 January, 1913. It occurred in three main phases: 1) An opening phase with the generation of Merapi-type pyroclastic flows (units F1, F2, F3) and a pyroclastic surge (S1), 2) A vent-clearing phase with strong explosions that produced Vulcanian-Soufriere-type pyroclastic flows (F4) and a pyroclastic surge (S2) which destroyed the summit dome decompressing the magma system, and 3) a Plinian phase with the establishment of a ∼ 23 km high column dispersing a fallout (C1) to the NE followed by the collapse of the column that generated a pyroclastic surge (S3) and 15-km long pumice-rich pyroclastic flows (F5). After the Eruption, remobilization of the pyroclastic material generated lahars in main gullies around the crater. Fallout C1 blanketed an area of ∼ 191,318 km2 covering the cities of Guzman, Guadalajara, and Saltillo (Coahuila) located at 725 km from the source. It had a volume of 1.4 km3 (0.57 km3 DRE = Dense Rock Equivalent). The total volume of pyroclastic flow and surge deposits was 0.26 km3 (0.07 km3 DRE) giving a total volume of the Eruption of 1.66 km3 (0.64 km3 DRE). The Plinian column lasted 4.6 h with a total mass of 1.5 × 1012 kg and a mass Eruption rate of 9.02 × 107 kg/s. The column height and the ejected magma volume indicate that the 1913 Eruption had a VEI = 5 being the largest event in the historical record of Colima Volcano. Juvenile scoria and pumice consisted of Pl > Opx > Cpx > Hbl + accessory titanomagnetite + Ap and Ol with reaction rims. Chemistry of juvenile scoria and pumice samples is andesitic very homogeneous (58.3 ± 0.5 wt.% SiO2) and similar to the 1818 juvenile products (58.9 ± 0.2 wt.% SiO2). The presence of banded scoria, olivine phenocrysts with reaction rims, and trace element variations strongly suggest that the 1913 Eruption was caused by a magma mixing event.
Costanza Bonadonna - One of the best experts on this subject based on the ideXlab platform.
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New insights into Eruption source parameters of the 1600 CE Huaynaputina Plinian Eruption, Peru
Bulletin of Volcanology, 2019Co-Authors: Jean-marie Prival, Costanza Bonadonna, Jean-claude Thouret, Saida Japura, Lucia Gurioli, Jersy Mariño, Kevin CuevaAbstract:In the Central Andes, large Plinian Eruptions (Volcanic Explosivity Index ≥ 5) occur at a relatively high frequency, i.e. average one every 2000 to 4000 years over the past 50,000 years in Peru. Such recurring explosive activity represents a significant challenge for regions typically hosting several million people (e.g. Southern Peru, Western Bolivia and Northern Chile). With VEI 6, the 1600 CE Huaynaputina Eruption is considered the largest historical Eruption in South America. We have re-examined the first Plinian phase of this Eruption in order to better assess critical Eruption source parameters (i.e. erupted volume, plume height, mass Eruption rate, Eruption duration).The revised bulk volume of the tephra-fall deposit associated with the Plinian phase is approximately 13–14 km3, almost twice the previous estimate (7–8 km3 within the 1 cm isopach) based on methods including power law, Weibull function and Bayesian linear regression. Tephra was dispersed by strong winds to the WNW as far as 400 km on Peruvian territory and then in the Pacific Ocean. Seven villages were buried, killing ~ 1500 people. The revised plume height estimate, 32.2 ± 2.5 km, is consistent with the early estimations. As a result, the Huaynaputina 1600 CE first Eruption phase lies in the upper part of the Plinian field close to the ultra-Plinian transition, making this event one of the largest in the past millennium which coincides with results from recent studies on palaeoclimatic impacts.
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Probabilistic evaluation of the physical impact of future tephra fallout events for the Island of Vulcano, Italy
Bulletin of Volcanology, 2016Co-Authors: Sebastien Biass, Costanza Bonadonna, Mauro Rosi, Federico Traglia, Marco Pistolesi, Pierino LestuzziAbstract:A first probabilistic scenario-based hazard assessment for tephra fallout is presented for La Fossa volcano (Vulcano Island, Italy) and subsequently used to assess the impact on the built environment. Eruption scenarios are based upon the stratigraphy produced by the last 1000 years of activity at Vulcano and include long–lasting Vulcanian and sub-Plinian Eruptions. A new method is proposed to quantify the evolution through time of the hazard associated with pulsatory Vulcanian Eruptions lasting from weeks to years, and the increase in hazard related to typical rainfall events around Sicily is also accounted for. The impact assessment on the roofs is performed by combining a field characterization of the buildings with the composite European vulnerability curves for typical roofing stocks. Results show that a sub-Plinian Eruption of VEI 2 is not likely to affect buildings, whereas a sub-Plinian Eruption of VEI 3 results in 90 % of the building stock having a ≥12 % probability of collapse. The hazard related to long-lasting Vulcanian Eruptions evolves through time, and our analysis shows that the town of Il Piano, located downwind of the preferential wind patterns, is likely to reach critical tephra accumulations for roof collapse 5–9 months after the onset of the Eruption. If no cleaning measures are taken, half of the building stock has a probability >20 % of suffering roof collapse.
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Probabilistic evaluation of the physical impact of future tephra fallout events for the Island of Vulcano, Italy
Bulletin of Volcanology, 2016Co-Authors: Sebastien Biass, Costanza Bonadonna, Mauro Rosi, Federico Traglia, Marco Pistolesi, Pierino LestuzziAbstract:A first probabilistic scenario-based hazard assessment for tephra fallout is presented for La Fossa volcano (Vulcano Island, Italy) and subsequently used to assess the impact on the built environment. Eruption scenarios are based upon the stratigraphy produced by the last 1000 years of activity at Vulcano and include long–lasting Vulcanian and sub-Plinian Eruptions. A new method is proposed to quantify the evolution through time of the hazard associated with pulsatory Vulcanian Eruptions lasting from weeks to years, and the increase in hazard related to typical rainfall events around Sicily is also accounted for. The impact assessment on the roofs is performed by combining a field characterization of the buildings with the composite European vulnerability curves for typical roofing stocks. Results show that a sub-Plinian Eruption of VEI 2 is not likely to affect buildings, whereas a sub-Plinian Eruption of VEI 3 results in 90 % of the building stock having a ≥12 % probability of collapse. The hazard related to long-lasting Vulcanian Eruptions evolves through time, and our analysis shows that the town of Il Piano, located downwind of the preferential wind patterns, is likely to reach critical tephra accumulations for roof collapse 5–9 months after the onset of the Eruption. If no cleaning measures are taken, half of the building stock has a probability >20 % of suffering roof collapse.
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Exploring the influence of vent location and Eruption style on tephra fall hazard from the Okataina Volcanic Centre, New Zealand
Bulletin of Volcanology, 2015Co-Authors: Mary Anne Thompson, Costanza Bonadonna, Jan M. Lindsay, Laura Sandri, Sebastien Biass, Gill Jolly, Warner MarzocchiAbstract:Uncertainties in modelling volcanic hazards are often amplified in geographically large systems which have a diverse Eruption history that comprises variable Eruption styles from many different vent locations. The ~700 km2 Okataina Volcanic Centre (OVC) is a caldera complex in New Zealand which has displayed a range of Eruption styles and compositions over its current phase of activity (26 ka–present), including one basaltic maar-forming Eruption, one basaltic Plinian Eruption and nine rhyolitic Plinian Eruptions. All three of these Eruption styles occurred within the past 3.5 ky, and any of these styles could occur in the event of a future Eruption. The location of a future Eruption is also unknown. Future vents could potentially open in one of three different areas which have been activated in the past 26 ky at the OVC: the Tarawera linear vent zone (LVZ) (five Eruptions), the Haroharo LVZ (five Eruptions) or outside of these LVZs (one Eruption). A future rhyolitic or basaltic Plinian Eruption from the OVC is likely to generate widespread tephra fall in loads that will cause significant disruption and have severe socio-economic impacts. Past OVC tephra hazard studies have focused on evaluating hazard from a rhyolitic Plinian Eruption at select vent locations in the OVC’s Tarawera LVZ. Here, we expand upon past studies by evaluating tephra hazard for all possible OVC Eruption vent areas and for both rhyolitic and basaltic Plinian Eruption styles, and explore how these parameters influence tephra hazard forecasts. Probabilistic volcanic hazard model BET_VH and advection–diffusion model TEPHRA2 were used to assess the hazard of accumulating ≥10 kg m−2 of tephra from both basaltic Plinian and rhyolitic Plinian Eruption styles, occurring from within the Tarawera LVZ, the Haroharo LVZ or other potential vent areas within the caldera. Our results highlight the importance of considering all the potential vent locations of a volcanic system, in order to capture the full Eruption catalogue in analyses (e.g. 11 Eruptions over 26 ky for the OVC versus only five Eruptions over 26 ky for the Tarawera LVZ), as well as the full spatial distribution of tephra hazard. Although the Tarawera LVZ has been prominently discussed in studies of OVC hazard because of its recent activity (1886 and ~1315 ad), we find that in the event of a future Eruption, the estimated likelihood of a vent opening within the Haroharo LVZ (last Eruption 5.6 ka) is equivalent (
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Reply to comment on: “Cobeñas, G., Thouret, J.-C., Bonadonna, C., Boivin, P., 2012. The c.2030 yr BP Plinian Eruption of El Misti volcano, Peru: Eruption dynamics and hazard implications. Journal of Volcanology and Geothermal Research 241–242, 105–12
Journal of Volcanology and Geothermal Research, 2014Co-Authors: Gisela Cobeñas, Costanza Bonadonna, Jean-claude Thouret, Pierre BoivinAbstract:Abstract The comment provided by Harpel et al. challenges our interpretation of the most recent Plinian Eruption of El Misti c.2070 yr BP* situated near the city of Arequipa, Peru (*revised age from our previously stated date of c.2030 BP). In our view, the sequence of deposits points to another example of a Plinian (pumice-rich) tephra fall followed by lithic-rich pyroclastic density currents (PDCs). Locally, late rockslide avalanches have emplaced mass-flow deposits on top of PDCs, while elsewhere post-Eruption lahars have led to their remobilization. One of the main criticisms from Harpel et al. was in our interpretation of the deposits as being of PDC origin, rather than post-Eruption lahars. We revise each of the diagnostic features that Harpel et al. have used for attributing the deposits to lahars. We present two tables of the revised age of the Eruption and criteria based on lithofacies, lithological components, grain-size distribution and statistical indices for each of the c.2070 yr BP-old PDC, lahar and mass-flow deposits. Our maps and simulations of PDCs and lahars, based on two numerical codes with volume inputs from identified deposits around El Misti, do not “fall short” of the hazard assessment goal.
Rosanna Bonasia - One of the best experts on this subject based on the ideXlab platform.
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long range hazard assessment of volcanic ash dispersal for a Plinian eruptive scenario at popocatepetl volcano mexico implications for civil aviation safety
Bulletin of Volcanology, 2014Co-Authors: Rosanna Bonasia, Lucia Capra, Claus Siebe, Chirara Scaini, Manuel Nathenson, Lilia Aranasalinas, Arnau FolchAbstract:Popocatepetl is one of Mexico’s most active volcanoes threatening a densely populated area that includes Mexico City with more than 20 million inhabitants. The destructive potential of this volcano is demonstrated by its Late Pleistocene–Holocene eruptive activity, which has been characterized by recurrent Plinian Eruptions of large magnitude, the last two of which destroyed human settlements in pre-Hispanic times. Popocatepetl’s reawakening in 1994 produced a crisis that culminated with the evacuation of two villages on the northeastern flank of the volcano. Shortly after, a monitoring system and a civil protection contingency plan based on a hazard zone map were implemented. The current volcanic hazards map considers the potential occurrence of different volcanic phenomena, including pyroclastic density currents and lahars. However, no quantitative assessment of the tephra hazard, especially related to atmospheric dispersal, has been performed. The presence of airborne volcanic ash at low and jet-cruise atmospheric levels compromises the safety of aircraft operations and forces re-routing of aircraft to prevent encounters with volcanic ash clouds. Given the high number of important airports in the surroundings of Popocatepetl volcano and considering the potential threat posed to civil aviation in Mexico and adjacent regions in case of a Plinian Eruption, a hazard assessment for tephra dispersal is required. In this work, we present the first probabilistic tephra dispersal hazard assessment for Popocatepetl volcano. We compute probabilistic hazard maps for critical thresholds of airborne ash concentrations at different flight levels, corresponding to the situation defined in Europe during 2010, and still under discussion. Tephra dispersal mode is performed using the FALL3D numerical model. Probabilistic hazard maps are built for a Plinian eruptive scenario defined on the basis of geological field data for the “Ochre Pumice” Plinian Eruption (4965 14C yr BP). FALL3D model input eruptive parameters are constrained through an inversion method carried out with the semi-analytical HAZMAP model and are varied by sampling them using probability density functions. We analyze the influence of seasonal variations on ash dispersal and estimate the average persistence of critical ash concentrations at relevant locations and airports. This study assesses the impact that a Plinian Eruption similar to the Ochre Pumice Eruption would have on the main airports of Mexico and adjacent areas. The hazard maps presented here can support long-term planning that would help minimize the impacts of such an Eruption on civil aviation.
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tephra fallout hazard assessment for a Plinian Eruption scenario at volcan de colima mexico
Journal of Volcanology and Geothermal Research, 2011Co-Authors: Rosanna Bonasia, Lucia Capra, Antonio Costa, G Macedonio, R SaucedoAbstract:Abstract Volcanic ash fallout associated with renewal of explosive activity at Colima, represents a serious threat to the surrounding urbanized area. Here we assess the tephra fallout hazard associated with a Plinian Eruption scenario. The eruptive history of Volcan de Colima shows that Plinian Eruptions occur approximately every 100 years and the last Eruption, the 1913, represents the largest historic Eruption of this volcano. We used the last Eruption as a reference to discuss volcanic hazard and risk scenarios connected with ash fallout. Tephra fallout deposits are modeled using HAZMAP, a model based on a semi-analytical solution of the advection–diffusion–sedimentation equation for volcanic particles. Based on a statistical study of wind profiles at Colima region, we first reconstructed ash loading maps and then computed ground load probability maps for different seasons. The obtained results show that a Plinian eruptive scenario at Volcan de Colima, could seriously damage more than 10 small towns and ranches, and potentially affect big cities located at tens of kilometers from the eruptive center. The probability maps obtained are aimed to give support to the risk mitigation strategies.
Jean-christophe Komorowski - One of the best experts on this subject based on the ideXlab platform.
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dynamics of the major Plinian Eruption of samalas in 1257 a d lombok indonesia
Bulletin of Volcanology, 2015Co-Authors: Celine Vidal, A. Michel, Jean-christophe Komorowski, Nicole Métrich, Indyo Pratomo, Nugraha Kartadinata, Oktory Prambada, Guillaume Carazzo, Franck Lavigne, Jessica RodysillAbstract:The 1257 A.D. caldera-forming Eruption of Samalas (Lombok, Indonesia) was recently associated with the largest sulphate spike of the last 2 ky recorded in polar ice cores. It is suspected to have impacted climate both locally and at a global scale. Extensive fieldwork coupled with sedimentological, geochemical and physical analyses of eruptive products enabled us to provide new constraints on the stratigraphy and eruptive dynamics. This four-phase continuous Eruption produced a total of 33–40 km3 dense rock equivalent (DRE) of deposits, consisting of (i) 7–9 km3 DRE of pumiceous Plinian fall products, (ii) 16 km3 DRE of pyroclastic density current deposits (PDC) and (iii) 8–9 km3 DRE of co-PDC ash that settled over the surrounding islands and was identified as far as 660 km from the source on the flanks of Merapi volcano (Central Java). Widespread accretionary lapilli-rich deposits provide evidence of the occurrence of a violent phreatomagmatic phase during the Eruption. With a peak mass Eruption rate of 4.6 × 108 kg/s, a maximum plume height of 43 km and a dispersal index of 110,500 km2, the 1257 A.D. Eruption stands as the most powerful Eruption of the last millennium. Eruption dynamics are consistent with an efficient dispersal of sulphur-rich aerosols across the globe. Remarkable reproducibility of trace element analysis on a few milligrammes of pumiceous tephra provides unequivocal evidence for the geochemical correlation of 1257 A.D. proximal reference products with distal tephra identified on surrounding islands. Hence, we identify and characterise a new prominent inter-regional chronostratigraphic tephra marker.
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Dynamics of the major Plinian Eruption of Samalas in 1257 A.D. (Lombok, Indonesia)
Bulletin of Volcanology, 2015Co-Authors: Céline M. Vidal, A. Michel, Jean-christophe Komorowski, Nicole Métrich, Indyo Pratomo, Nugraha Kartadinata, Oktory Prambada, Guillaume Carazzo, Franck Lavigne, Jessica RodysillAbstract:The 1257 A.D. caldera-forming Eruption of Samalas (Lombok, Indonesia) was recently associated with the largest sulphate spike of the last 2 ky recorded in polar ice cores. It is suspected to have impacted climate both locally and at a global scale. Extensive fieldwork coupled with sedimentological, geochemical and physical analyses of eruptive products enabled us to provide new constraints on the stratigraphy and eruptive dynamics. This four-phase continuous Eruption produced a total of 33–40 km^3 dense rock equivalent (DRE) of deposits, consisting of (i) 7–9 km^3 DRE of pumiceous Plinian fall products, (ii) 16 km^3 DRE of pyroclastic density current deposits (PDC) and (iii) 8–9 km^3 DRE of co-PDC ash that settled over the surrounding islands and was identified as far as 660 km from the source on the flanks of Merapi volcano (Central Java). Widespread accretionary lapilli-rich deposits provide evidence of the occurrence of a violent phreatomagmatic phase during the Eruption. With a peak mass Eruption rate of 4.6 × 10^8 kg/s, a maximum plume height of 43 km and a dispersal index of 110,500 km^2, the 1257 A.D. Eruption stands as the most powerful Eruption of the last millennium. Eruption dynamics are consistent with an efficient dispersal of sulphur-rich aerosols across the globe. Remarkable reproducibility of trace element analysis on a few milligrammes of pumiceous tephra provides unequivocal evidence for the geochemical correlation of 1257 A.D. proximal reference products with distal tephra identified on surrounding islands. Hence, we identify and characterise a new prominent inter-regional chronostratigraphic tephra marker.
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eyewitness stratigraphy chemistry and eruptive dynamics of the 1913 Plinian Eruption of volcan de colima mexico
Journal of Volcanology and Geothermal Research, 2010Co-Authors: R Saucedo, José Luis Macías, Jean-christophe Komorowski, James E. Gardner, J L Arce, J C Gavilanes, Gabriel ValdezmorenoAbstract:Abstract Based on the stratigraphic record of the deposits, analysis of previous works, historic archives, and eyewitness accounts the 1913 Eruption of Volcan de Colima was reconstructed. The Eruption started in 17 January and peaked in 20 January, 1913. It occurred in three main phases: 1) An opening phase with the generation of Merapi-type pyroclastic flows (units F1, F2, F3) and a pyroclastic surge (S1), 2) A vent-clearing phase with strong explosions that produced Vulcanian-Soufriere-type pyroclastic flows (F4) and a pyroclastic surge (S2) which destroyed the summit dome decompressing the magma system, and 3) a Plinian phase with the establishment of a ∼ 23 km high column dispersing a fallout (C1) to the NE followed by the collapse of the column that generated a pyroclastic surge (S3) and 15-km long pumice-rich pyroclastic flows (F5). After the Eruption, remobilization of the pyroclastic material generated lahars in main gullies around the crater. Fallout C1 blanketed an area of ∼ 191,318 km2 covering the cities of Guzman, Guadalajara, and Saltillo (Coahuila) located at 725 km from the source. It had a volume of 1.4 km3 (0.57 km3 DRE = Dense Rock Equivalent). The total volume of pyroclastic flow and surge deposits was 0.26 km3 (0.07 km3 DRE) giving a total volume of the Eruption of 1.66 km3 (0.64 km3 DRE). The Plinian column lasted 4.6 h with a total mass of 1.5 × 1012 kg and a mass Eruption rate of 9.02 × 107 kg/s. The column height and the ejected magma volume indicate that the 1913 Eruption had a VEI = 5 being the largest event in the historical record of Colima Volcano. Juvenile scoria and pumice consisted of Pl > Opx > Cpx > Hbl + accessory titanomagnetite + Ap and Ol with reaction rims. Chemistry of juvenile scoria and pumice samples is andesitic very homogeneous (58.3 ± 0.5 wt.% SiO2) and similar to the 1818 juvenile products (58.9 ± 0.2 wt.% SiO2). The presence of banded scoria, olivine phenocrysts with reaction rims, and trace element variations strongly suggest that the 1913 Eruption was caused by a magma mixing event.
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reconstruction and analysis of sub Plinian tephra dispersal during the 1530 a d soufriere guadeloupe Eruption implications for scenario definition and hazards assessment
Journal of Volcanology and Geothermal Research, 2008Co-Authors: Jean-christophe Komorowski, Y Legendre, B Caron, Georges BoudonAbstract:Abstract The last magmatic Eruption of Soufriere of Guadeloupe dated at 1530 A.D. (Soufriere Eruption) is characterized by an onset with a partial flank-collapse and emplacement of a debris-avalanche that was followed by a sub-Plinian VEI 2–3 explosive short-lived Eruption (Phase-1) with a column that reached a height between 9 and 12 km producing about 3.9 × 10 6 m 3 DRE (16.3 × 10 6 m 3 bulk) of juvenile products. The column recurrently collapsed generating scoriaceous pyroclastic flows in radiating valleys up to a distance of 5–6 km with a maximum interpolated bulk deposit volume of 11.7 × 10 6 m 3 (5 × 10 6 m 3 DRE). We have used HAZMAP, a numerical simple first-order model of tephra dispersal [Macedonio, G., Costa, A., Longo, A., 2005. A computer model for volcanic ash fallout and assessment of subsequent hazard. Comput. Geosci. 31, 837–845] to reconstruct to a first approximation the potential dispersal of tephra and associated tephra mass loadings generated by the sub-Plinian Phase 1 of the 1530 A.D. Eruption. We have tested our model on a deterministic average dry season wind profile that best-fits the available data as well as on a set of randomly selected wind profiles over a 5 year interval that allows the elaboration of probabilistic maps for the exceedance of specific tephra mass load thresholds. Results show that in the hypothesis of a future 1530 A.D. scenario, populated areas to a distance of 3–4 km west–southwest of the vent could be subjected to a static load pressure between 2 and 10 kPa in case of wet tephra, susceptible to cause variable degrees of roof damage. Our results provide volcanological input parameters for scenario and event-tree definition, for assessing volcanic risks and evaluating their impact in case of a future sub-Plinian Eruption which could affect up to 70 000 people in southern Basse-Terre island and the region. They also provide a framework to aid decision-making concerning land management and development. A sub-Plinian Eruption is the most likely magmatic scenario in case of a future Eruption of this volcano which has shown, since 1992, increasing signs of low-energy seismic, thermal, and acid degassing unrest without significant deformation.
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Modelling the impact of a hypothetical sub-Plinian Eruption at La Soufrière of Guadeloupe (Lesser Antilles)
Journal of Volcanology and Geothermal Research, 2008Co-Authors: Robin Spence, Jean-christophe Komorowski, K. Saito, A. Brown, Antonios Pomonis, G. Toyos, Peter J. BaxterAbstract:Abstract This paper describes the development and application of an impact model for a future hypothetical sub-Plinian Eruption of La Soufriere of Guadeloupe. The model was designed to assess the impact from either a single or multiple Eruption scenarios, each defined in terms of a map of the intensity of three volcanic hazards; volcanogenic earthquake, tephra fallout and pyroclastic density currents. The impact from the three hazards can be assessed independently or alternatively the joint impact of the three hazards can be assessed. The outputs that are produced from the model are; the number of buildings with collapsed roofs, and the number of fatal and non-fatal casualties. Two versions of the impact model were developed, one that uses a spreadsheet and another that is implemented using a Geographical Information System (GIS). Both versions use the same types of hazard inputs and vulnerability functions to derive the number of building collapses and casualties, but have different spatial resolution of the final outputs. The spreadsheet version aggregates the results at a zone level defined specifically for this project whereas the GIS was designed to produce results using 250 m grid-squares. The outputs from the two versions, when using the same Eruption scenario, produced somewhat different results, highlighting the importance of defining the appropriate spatial resolution. The vulnerability functions were developed using data on the building stock that was collected by a local survey, in which data on the form of construction, condition, location and types of openings and the variation of these parameters across the affected area were collected. The vulnerability functions incorporated new assessments of fire risks induced by pyroclastic density currents. The model was applied to La Soufriere using a range of input hazard scenarios based on reconstruction of the most recent sub-Plinian magmatic Eruption which occurred in 1530 AD. A sensitivity analysis of the model was carried out choosing the inputs from a range of defined input values. The effect on losses and casualties of a range of possible mitigation measures was assessed by running the original model and the modified model using the same input Eruption scenario. A separate casualty treatment model was also developed and tested.