Recent Major Eruptions Research Articles

Meteorological Controls on Local and Regional Volcanic Ash Dispersal

Volcanic ash has the capacity to impact human health, livestock, crops and infrastructure, including international air traffic. For recent major eruptions, information on the volcanic ash plume has been combined with relatively coarse-resolution meteorological model output to provide simulations of regional ash dispersal, with reasonable success on the scale of hundreds of kilometres. However, to predict and mitigate these impacts locally, significant improvements in modelling capability are required. Here, we present results from a dynamic meteorological-ash-dispersion model configured with sufficient resolution to represent local topographic and convectively-forced flows. We focus on an archetypal volcanic setting, Soufrière, St Vincent, and use the exceptional historical records of the 1902 and 1979 eruptions to challenge our simulations. We find that the evolution and characteristics of ash deposition on St Vincent and nearby islands can be accurately simulated when the wind shear associated with the trade wind inversion and topographically-forced flows are represented. The wind shear plays a primary role and topographic flows a secondary role on ash distribution on local to regional scales. We propose a new explanation for the downwind ash deposition maxima, commonly observed in volcanic eruptions, as resulting from the detailed forcing of mesoscale meteorology on the ash plume.

Human survival in volcanic eruptions: Thermal injuries in pyroclastic surges, their causes, prognosis and emergency management

This study of burns patients from two eruptions of Merapi volcano, Java, in 1994 and 2010, is the first detailed analysis to be reported of thermal injuries in a large series of hospitalised victims of pyroclastic surges, one of the most devastating phenomena in explosive eruptions. Emergency planners in volcanic crises in populated areas have to integrate the health sector into disaster management and be aware of the nature of the surge impacts and the types of burns victims to be expected in a worst scenario, potentially in numbers and in severity that would overwhelm normal treatment facilities. In our series, 106 patients from the two eruptions were treated in the same major hospital in Yogyakarta and a third of these survived. Seventy-eight per cent were admitted with over 40% TBSA (total body surface area) burns and around 80% of patients were suspected of having at least some degree of inhalation injury as well. Thirty five patients suffered over 80% TBSA burns and only one of these survived. Crucially, 45% of patients were in the 40–79% TBSA range, with most suspected of suffering from inhalation injury, for whom survival was most dependent on the hospital treatment they received. After reviewing the evidence from recent major eruptions and outlining the thermal hazards of surges, we relate the type and severity of the injuries of these patients to the temperatures and dynamics of the pyroclastic surges, as derived from the environmental impacts and associated eruption processes evaluated in our field surveys and interviews conducted by our multi-disciplinary team. Effective warnings, adequate evacuation measures, and political will are all essential in volcanic crises in populated areas to prevent future catastrophes on this scale.

Dating the Last Major Eruption of Long Island, Papua New Guinea: The Evidence From Dampier’s 1700 Voyage on the Roebuck

William Dampier, one of England’s greatest navigators, named, described, and drew a profile of Long Island, Papua New Guinea in 1700. As this island produced a very large volcanic eruption with a disputed seventeenth- or eighteenth-century date, his observations assist in determining whether the eruption occurred before or after his visit. This contribution uses Dampier’s recorded observations to elucidate where the Roebuck was when the Long Island profile was drawn so that an appropriate comparison can be made with a modern profile of the island. This comparison confirms that the most recent major eruption of Long Island occurred before Dampier’s observations were made.

A revised age of ad 667–699 for the latest major eruption at Rabaul

The most recent major eruption at Rabaul was one of the largest known volcanic events at this complex system, having a volcanic explosivity index (VEI) rating of 6. The eruption generated widespread pumice lapilli and ash fall deposits and ignimbrites of different types. The total volume of pyroclastic material produced in the eruption exceeded 11 km3 and led to a new phase of collapse within Rabaul Caldera. Initial 14C dating of the event yielded an age of about 1400 years bp, and the eruption became known as the “1400 bp” eruption. Previous analyses of the timing of the eruption have sought to link it to events in ad 536 and ad 639. However, we have re-evaluated the age of the eruption using the Bayesian wiggle-match radiocarbon dating method, and the eruption is now thought to have occurred in the interval ad 667–699. The only significant equatorial eruptions recorded in both Greenland and Antarctic ice during this interval are at ad 681 and ad 684, dates that coincide with frost rings in bristlecone pines of western USA in the same years. Definitively linking the Rabaul eruption to this narrow age range will require identification of Rabaul tephra in the ice records. However, it is proposed that a new working hypothesis for the timing of the most recent major eruption at Rabaul is that it occurred in the interval ad 681–684.

Geological and Geomorphological Value of the Monogenetic Volcanoes in Wudalianchi National Park, NE China

Cenozoic Wudalianchi volcanic field, which is located in northeast China, about 1,800 km away from the Pacific–Eurasia plate boundary, is characterized by 14 monogenetic basaltic volcanoes. These small-scale volcanoes are widely distributed in region and were formed by discrete, relatively short-lived volcanic eruptions. The activity of the basaltic volcanic field occurred during seven eruptive episodes spanning a period of 2.10 million years. Because the recent major eruptions—Laoheishan and Huoshaoshan volcanoes—took place in 1719–21 AD, the Wudalianchi volcanic field contains an exceptionally well-preserved range of volcanic landforms. It contains well-displayed examples of extensive lava flows, including a wide variety of lava flow surfaces, subsidiary pyroclastic cones, hornitos, and deposits of volcanic debris. As a member of the tentative list of World Natural Heritage in China, Wudalianchi National Park preserves and protects a high level of geological and geomorphological value with spectacular landforms and structures produced by geologically young volcanism.

Sequence of the 1895 eruption of the Zao volcano, Tohoku Japan

The most recent major eruption event of the Zao volcano comprised a series of phreatic eruption episodes on 15 and 19 February, 22 August, and 27–28 September 1895, with several precursory vulcanian eruptions during February–July 1894. All were generated at the Okama crater lake located inside the Umanose caldera. The eruption products consist mainly of hydrothermally altered ash with altered blocks, except for ash from 1984. The eruption deposits of 1895 are divided lithologically into six layers (1–6). Comparison of the document with the lithofacies of deposits shows that layers 1, 2, 3–4, and 5–6 were correlated respectively with eruption episodes of 15 February (episode 1), 19 February (episode 2), 22 August (episode3), and 27–28 September (episode 4). During these four episodes, ca. 0.5%, 0.5%, 1.5%, and 98% of the total mass of the products had been discharged. Based on lithologic, stratigraphic, granulometric, and component analyses and on distributional features for these layers, the following depositional mechanisms were inferred. Layers 1, 3, and 4 were formed mainly from their related small pyroclastic density currents, whereas layer 2 resulted mainly from a small pyroclastic fall. In contrast, layers 5 and 6 are larger-scale near-vent pyroclastic fall deposits from ash clouds and eruption clouds, which might have included some juvenile fragments. The three early episodes in 1985 led to the climactic episode of 27–28 September. Furthermore, the andesitic magma chamber at <3kb depth, which caused the 1894 vulcanian eruptions, became a hydrothermal alteration source for the 1895 erupted materials. The chamber was re-activated before 1895 eruption by injection of basaltic magmas from greater depth. The injection reached maximum at the climactic event. The inferred course of that series of eruption episodes provides useful information to predict future volcanic phreatic-type eruptions at this volcano.

Late Holocene Pelean-style eruption at Tacana volcano, Mexico and Guatemala: Past, present, and future hazards

Research Article| August 01, 2000 Late Holocene Peléan-style eruption at Tacaná volcano, Mexico and Guatemala: Past, present, and future hazards J.L. Macías; J.L. Macías 1Instituto de Geofísica, Universidad Nacional Autónoma de México, Coyoacán 04510, México D.F., México Search for other works by this author on: GSW Google Scholar J.M. Espíndola; J.M. Espíndola 1Instituto de Geofísica, Universidad Nacional Autónoma de México, Coyoacán 04510, México D.F., México Search for other works by this author on: GSW Google Scholar A. García-Palomo; A. García-Palomo 1Instituto de Geofísica, Universidad Nacional Autónoma de México, Coyoacán 04510, México D.F., México Search for other works by this author on: GSW Google Scholar K.M. Scott; K.M. Scott 2Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661, USA Search for other works by this author on: GSW Google Scholar S. Hughes; S. Hughes 3Department of Geology, State University of New York, 876 Natural Science Complex, Buffalo, New York 14260, USA Search for other works by this author on: GSW Google Scholar J.C. Mora J.C. Mora 4Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Firenze, Italia Search for other works by this author on: GSW Google Scholar GSA Bulletin (2000) 112 (8): 1234–1249. https://doi.org/10.1130/0016-7606(2000)112<1234:LHPEAT>2.0.CO;2 Article history received: 09 Apr 1999 rev-recd: 20 Dec 1999 accepted: 21 Dec 1999 first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J.L. Macías, J.M. Espíndola, A. García-Palomo, K.M. Scott, S. Hughes, J.C. Mora; Late Holocene Peléan-style eruption at Tacaná volcano, Mexico and Guatemala: Past, present, and future hazards. GSA Bulletin 2000;; 112 (8): 1234–1249. doi: https://doi.org/10.1130/0016-7606(2000)112<1234:LHPEAT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Tacaná volcano, located on the border between Mexico and Guatemala, marks the northern extent of the Central American volcanic chain. Composed of three volcanic structures, it is a volcanic complex that has had periodic explosive eruptions for at least the past 40 k.y. The most recent major eruption occurred at the San Antonio volcano, the youngest volcanic edifice forming the complex, about 1950 yr ago. The Peléan style eruption, issued from the southwest part of the dome, and swept a 30° sector with a hot block and ash flow that traveled about 14 km along the Cahoacán ravine. Deposits from this event are well exposed around the town of Mixcun and were therefore given the name of that town, the Mixcun flow deposit. The Mixcun flow deposit is, in the channel facies, a light gray, massive, thick (>10 m), matrix-supported unit with dispersed lithic clasts of gravel to boulder size, divisible in some sections into a variable number of flow units. The overbank facies is represented by a thin (<1 m), massive, matrix-supported unit. In both of these facies the deposit has disseminated charcoal, fumarolic pipes, and juvenile lithics with cooling joints. The Mixcun flow deposit contains clasts of (1) light gray, dense andesite, (2) dark gray, glassy and banded andesite, and (3) minor altered red andesite from the edifice, set in a matrix of sand and silt. The Mixcun flow deposit covers an area of at least 25 km2 and has a minimum estimated volume of 0.12 km3. Basaltic-andesite inclusions (54% SiO2) and various signs of disequilibrium in the mineral assemblage of the two-pyroxene andesitic products (60%–63% SiO2) suggest that magma mixing may have triggered the eruption. Following deposition of the Mixcun flow deposit andesitic to dacitic (62%–64% SiO2) lava flows were extruded and a dacitic dome (64.4% SiO2) at the San Antonio summit formed. Syn-eruptive and posteruptive lahars flooded the main drainages of the Cahoacán and Izapa-Mixcun valleys in the area of the present city of Tapachula (population 250000) and the pre-Hispanic center of Izapa. Three radiocarbon ages date this event between A.D. 25 and 72 (range ±1σ, 38 B.C.–A.D. 216), which correlates with a halt in construction at Izapa (Hato phase of ca. 50 B.C.–A.D. 100), probably due to temporary abandonment of the city caused by lahars. Another similar event would produce extensive damage to the towns (population of about 68,000 people) now built upon the Mixcun flow deposit. The main summit of Tacaná volcano continues to show signs of fumarolic activity; the most recent period of activity in 1985–1986 culminated in a minor phreatic explosion. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.