An objective method for mapping hazardous flow deposits from the stratigraphic record of stratovolcanoes: a case example from Montagne Pelée

• Published in: Bulletin of volcanology Vol. 63; no. 2-3; pp. 98 - 111
• Main Authors: Burt, M. L., Wadge, G., Curnow, R. N.
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 2001; Springer Nature B.V
• Subjects: Crystalline rocks; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Geographic information systems; Geographical information systems; Hazard assessment; Igneous and metamorphic rocks petrology, volcanic processes, magmas; Information systems; Methods; Natural hazards: prediction, damages, etc; Probability theory; Sampling; Studies; Volcanoes; Volcanology; Martinique; Lesser Antilles; Antilles; Mount Pelee; West Indies; volcanic ash; natural hazards maps; polygons; volcanic rocks; probability; boulders; explosive eruptions; geographic information systems; igneous rocks; cartography; volcanic risk; stratigraphy; Caribbean region; stratovolcanoes; pyroclastics; ash flows; pelean-type eruptions; plinian-type eruptions; statistics
• ISSN: 0258-8900; 1432-0819
• DOI: 10.1007/s004450100128

A method is described that enables a variety of maps, which indicate the probabilities of deposition, to be constructed in a reproducible manner from the stratigraphie information typically available at well-studied stratovoicanoes. These maps can then be used as a basis for hazard assessment. The sampling of the deposits of previous eruptions is subject to uncertainties due to erosion, sectoral deposition and non-exposure. A model-based, iterative algorithm is used to compensate for the incomplete sampling. For each site, the available evidence from the other sites is used to estimate the probability of deposition for missing deposits. A geographical information system (GIS)-based method that uses Thiessen polygons to represent the presence or absence of deposits, together with simple cartographic rules based on depositional processes, then defines the extent of deposition. The combined operation of these two techniques is presented for Montagne Pelée in Martinique, using the amended stratigraphic record of Smith and Roobol (1990) for the past 6000 years. Three types of maps are created: maps for individual depositional events (the 1902 block-and-ash flow and surge deposits are used to verify the technique); maps for different deposit types aggregated over 6000 years of activity; and scenario maps which, in Montagne Pelée’s case, recognise that during the next Peléean or Plinian eruption a variety of hazards will have to be confronted.