Research Article| July 01, 2002 Origin of the Mount Pinatubo climactic eruption cloud: Implications for volcanic hazards and atmospheric impacts Sébastien Dartevelle; Sébastien Dartevelle 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7, Canada, and BRUEGEL, Université Libre de Bruxelles, CP 160/02, 50 Avenue Roosevelt, 1050 Brussels, Belgium Search for other works by this author on: GSW Google Scholar Gérald G.J. Ernst; Gérald G.J. Ernst 2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK Search for other works by this author on: GSW Google Scholar John Stix; John Stix 3Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7, Canada Search for other works by this author on: GSW Google Scholar Alain Bernard Alain Bernard 4BRUEGEL, Université Libre de Bruxelles, CP 160/02, 50 Avenue Roosevelt, 1050 Brussels, Belgium Search for other works by this author on: GSW Google Scholar Author and Article Information Sébastien Dartevelle 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7, Canada, and BRUEGEL, Université Libre de Bruxelles, CP 160/02, 50 Avenue Roosevelt, 1050 Brussels, Belgium Gérald G.J. Ernst 2Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK John Stix 3Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7, Canada Alain Bernard 4BRUEGEL, Université Libre de Bruxelles, CP 160/02, 50 Avenue Roosevelt, 1050 Brussels, Belgium Publisher: Geological Society of America Received: 07 Oct 2001 Revision Received: 05 Mar 2002 Accepted: 20 Mar 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (7): 663–666. https://doi.org/10.1130/0091-7613(2002)030<0663:OOTMPC>2.0.CO;2 Article history Received: 07 Oct 2001 Revision Received: 05 Mar 2002 Accepted: 20 Mar 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Sébastien Dartevelle, Gérald G.J. Ernst, John Stix, Alain Bernard; Origin of the Mount Pinatubo climactic eruption cloud: Implications for volcanic hazards and atmospheric impacts. Geology 2002;; 30 (7): 663–666. doi: https://doi.org/10.1130/0091-7613(2002)030<0663:OOTMPC>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 SocietyGeology Search Advanced Search Abstract Volcanic-ash clouds can be fed by an upward-directed eruption column (Plinian column) or by elutriation from extensive pyroclastic flows (coignimbrite cloud). There is considerable uncertainty about which mechanism is dominant in large-scale eruptions. Here we analyze in a novel way a comprehensive grain-size database for pyroclastic deposits. We demonstrate that the Mount Pinatubo climactic eruption deposits were substantially derived from coignimbrite clouds, and not only by a Plinian cloud, as generally thought. Coignimbrite ash-fall deposits are much richer in breathable <10 μm ash (5–25 wt%) than pure Plinian ash at most distances from the source volcano. We also show that coignimbrite ash clouds, as at Pinatubo, are expected to be more water rich than Plinian clouds, leading to removal of more HCl prior to stratospheric injection, thereby reducing their atmospheric impact. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Satellite SO2 and ash measurements of Mount Spurr's three 1992 volcanic clouds are compared with ground‐based observations to develop an understanding of the physical and chemical evolution of volcanic clouds. Each of the three eruptions with ratings of volcanic explosivity index three reached the lower stratosphere (14 km asl), but the clouds were mainly dispersed at the tropopause by moderate to strong (20–40 m/s) tropospheric winds. Three stages of cloud evolution were identified. First, heavy fallout of large (>500 μm) pyroclasts occurred close to the volcano (<25 km from the vent) during and immediately after the eruptions, and the cloud resembled an advected gravity current. Second, a much larger, highly elongated region marked by a secondary‐mass maximum occurred 150–350 km downwind in at least two of the three events. This was the result of aggregate fallout of a bimodal size distribution including fine (<25 μm) ash that quickly depleted the solid fraction of the volcanic cloud. For the first several hundred kilometers, the cloud spread laterally, first as an intrusive gravity current and then by wind shear and diffusion as downwind cloud transport occurred at the windspeed (during the first 18–24 h). Finally, the clouds continued to move through the upper troposphere but began decreasing in areal extent, eventually disappearing as ash and SO2 were removed by meteorological processes. Total SO2 in each eruption cloud increased by the second day of atmospheric residence, possibly because of oxidation of coerupted H2S or possibly because of the effects of sequestration by ice followed by subsequent SO2 release during fallout and desiccation of ashy hydrometeors. SO2 and volcanic ash travelled together in all the Spurr volcanic clouds. The initial (18–24 h) area expansion of the clouds and the subsequent several days of drifting were successfully mapped by both SO2 (ultraviolet) and ash (infrared) satellite imagery.
Abstract Most of the hazardous volcanoes, especially those in developing countries, have not been studied or regularly monitored. Moderate-to-high spatial resolution and 3D satellite remote sensing offers a low-cost route to mapping and assessing hazards at volcanoes worldwide. The capabilities of remote sensing techniques are reviewed and an update of recent developments is provided, with emphasis on low-cost data, including optical (Landsat, ASTER, SPOT, CORONA), topographic (3D ASTER, SRTM) and synthetic aperture radar data. Applications developed here illustrate capabilities of relevant remote sensing data to map hazardous volcanic terrain and derive quantitative data, focusing on mapping and monitoring of volcanic morphology. Limitations of the methods, assessment of errors and planned new sensors are also discussed.
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