Perils in distinguishing phreatic from phreatomagmatic ash; insights into the eruption mechanisms of the 6 August 2012 Mt. Tongariro eruption, New Zealand

Pardo, Natalia; Cronin, Shane J.; Németh, Károly; Brenna, Marco; Schipper, C. Ian; Bréard, E.; White, James D. L.; Procter, Jonathan; Stewart, Bob; Agustín-Flores, Javier; Moebis, Anja; Zernack, Anke; Keresztúri, Gábor; Lube, Gert; Auer, Andreas; Neall, Vincent E.; Wallace, Clel

doi:10.1016/j.jvolgeores.2014.05.001

Cited by 80 publications

(51 citation statements)

References 61 publications

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“…The results have been compared with the main plume that travelled eastwards. Some ash travelled north from Te Maari, but it was clear Pardo et al, 2014;Turner et al, 2014) that these ash deposits were produced by low-angle directed blasts. .…”

Section: And the Ganser Equationmentioning

confidence: 99%

Forecasting volcanic ash deposition using HYSPLIT

Hurst¹,

Davis²

2017

J Appl. Volcanol.

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A major source of error in forecasting where airborne volcanic ash will travel and land is the wind pattern above and around the volcano. GNS Science, in conjunction with MetService, is seeking to move its routine ash forecasts from using the ASHFALL program, which cannot allow for horizontal variations in the wind pattern, to HYSPLIT, which uses a full 4-D atmospheric model. This has required some extensions to the standard version of the HYSPLIT program, both to get appropriate source terms and to handle the fall velocities of ash particles larger than 100 microns. Application of the modified HYSPLIT to ash from the Te Maari eruption of 6 August 2012 from Tongariro volcano gives results similar to the observed ash distribution. However, it was also apparent that the high precision of these results could be misleading in actual forecasting situations, and there needs to be ways in which the likely errors in atmospheric model winds can be incorporated into ash models, to show all the areas in which there is a significant likelihood of deposited ash with each particular volcanic eruption model.

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Section: And the Ganser Equationmentioning

confidence: 99%

Forecasting volcanic ash deposition using HYSPLIT

Hurst¹,

Davis²

2017

J Appl. Volcanol.

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“…Cashman and Hoblitt [2004] identified a juvenile component in the precursory ash that erupted from Mount St. Helens 3 months before the onset of the eruption on 18 May 1980. However, Pardo et al [2014] highlighted uncertainties in distinguishing phreatomagmatic from phreatic products due to the extreme difficulty of truly differentiating between the juvenile component from well-preserved material from previous eruptions. Those authors argued that excluding the presence of fresh magma input within an eruption from the study of ash deposits only is not straightforward, and that strong evidence that new magma has not erupted is the lack of particles with a distinct glass composition.…”

Section: Introductionmentioning

confidence: 99%

Eruptive activity at Turrialba volcano (Costa Rica): Inferences from ³He/⁴He in fumarole gases and chemistry of the products ejected during 2014 and 2015

Rizzo

Piazza

Moor

et al. 2016

Geochem Geophys Geosyst

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A new period of eruptive activity started at Turrialba volcano, Costa Rica, in 2010 after almost 150 years of quiescence. This activity has been characterized by sporadic explosions whose frequency clearly increased since October 2014. This study aimed to identify the mechanisms that triggered the resumption of this eruptive activity and characterize the evolution of the phenomena over the past 2 years. We integrate 3He/4He data available on fumarole gases collected in the summit area of Turrialba between 1999 and 2011 with new measurements made on samples collected between September 2014 and February 2016. The results of a petrological investigation of the products that erupted between October 2014 and May 2015 are also presented. We infer that the resumption of eruptive activity in 2010 was triggered by a replenishment of the plumbing system of Turrialba by a new batch of magma. This is supported by the increase in 3He/4He values observed since 2005 at the crater fumaroles and by comparable high values in September 2014, just before the onset of the new eruptive phase. The presence of a number of fresh and juvenile glassy shards in the erupted products increased between October 2014 and May 2015, suggesting the involvement of new magma with a composition similar to that erupted in 1864–1866. We conclude that the increase in 3He/4He at the summit fumaroles since October 2015 represents strong evidence of a new phase of magma replenishment, which implies that the level of activity remains high at the volcano.

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“…The crystals typically range in size from several millimeters down to a few micrometers. Crystals may also fragment during particularly violent explosive eruptions, but generally, fractures occur at crystal margins and certain grain sizes of ash may reflect the original crystal modal size distribution (e.g., in phreatomagmatic or phreatic eruptions) [ Pardo et al ., ]. In basaltic andesite/andesite magmas with moderate to high H 2 O contents, the typical crystals include plagioclase feldspar, pyroxene, and titanomagnetite, along with less common hornblende and/or olivine.…”

Section: Discussionmentioning

confidence: 99%

Posteruptive impacts of pyroclastic deposits from basaltic andesite stratovolcanoes on surface water composition

et al. 2016

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Volcanic ash deposition following explosive eruptions can pose significant hazards for water quality, human health, agriculture, and infrastructure functionality. Many studies have examined how fresh ash deposition may lower the pH of, and introduce a range of potentially toxic elements into, exposed surface waters. However, no study has yet determined the effects on water composition as a result of mechanical pyroclast disaggregation and production of new fresh particle surfaces and increasingly fine grained particles. Such disaggregation could result from natural posteruptive processes such as debris avalanches, lahars, or fluvial/aeolian transport and human activities such as cleanup efforts or mining of pyroclastic deposits. The posteruption time scales of pyroclast disaggregation may vary from months in moist tropical or temperate environments to years or decades in arid settings. Here we show, for the first time in experimental studies, that mechanical milling of pyroclasts will introduce a range of elements into exposed waters, including Al, which can be toxic at elevated levels, and Na, which increases the electrical conductivity of solutions. The pH of leaching solutions also increases by several log units. Such dramatic changes on the experimental scale may have implications for surface water composition in posteruptive settings, necessitating longer‐term risk assessments for ecosystem health and consideration of the role of pyroclastic deposits in element cycling in volcanically active regions.

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Perils in distinguishing phreatic from phreatomagmatic ash; insights into the eruption mechanisms of the 6 August 2012 Mt. Tongariro eruption, New Zealand

Cited by 80 publications

References 61 publications

Forecasting volcanic ash deposition using HYSPLIT

Forecasting volcanic ash deposition using HYSPLIT

Eruptive activity at Turrialba volcano (Costa Rica): Inferences from ³He/⁴He in fumarole gases and chemistry of the products ejected during 2014 and 2015

Posteruptive impacts of pyroclastic deposits from basaltic andesite stratovolcanoes on surface water composition

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Perils in distinguishing phreatic from phreatomagmatic ash; insights into the eruption mechanisms of the 6 August 2012 Mt. Tongariro eruption, New Zealand

Cited by 80 publications

References 61 publications

Forecasting volcanic ash deposition using HYSPLIT

Forecasting volcanic ash deposition using HYSPLIT

Eruptive activity at Turrialba volcano (Costa Rica): Inferences from 3He/4He in fumarole gases and chemistry of the products ejected during 2014 and 2015

Posteruptive impacts of pyroclastic deposits from basaltic andesite stratovolcanoes on surface water composition

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Product

Resources

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Eruptive activity at Turrialba volcano (Costa Rica): Inferences from ³He/⁴He in fumarole gases and chemistry of the products ejected during 2014 and 2015