Titre du document / Document title
Slopes of western Galapagos volcanoes from airborne interferometric radar
Auteur(s) / Author(s)
MOUGINIS-MARK P. J. (1) ;
ROWLAND S. K. (1) ;
GARBEIL H. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Hawaii Institute of Geophysics and Planetology and Hawaii Center for Volcanology, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, ETATS-UNIS
Résumé / Abstract
The distribution of slopes on the six basaltic shield volcanoes in the Western Galapagos Islands is investigated using a digital elevation model derived from airborne interferometric radar (TOPSAR) data. These measurements have a spatial sampling of 10 m/pixel, a vertical accuracy of 3 to 5 m, and constitute the highest resolution, most complete, topographic data set available for the islands. Volcano heights are determined to range from 1,124 m (Sierra Negra) to 1,710 m (Wolf). Over extensive areas of each volcano, slopes exceed 25°, with the highest slopes being -37° on Wolf and ∼36° on Fernandina. We confirm that two morphologic subgroups exist: Cerro Azul, Fernandina, and Wolf, with deep calderas (depth between 40-60% of the subaerial height of the volcano) and steep (>20°) maximum slopes at elevations between ∼60 and 80% of the volcano height; and Alcedo, Darwin, and Sierra Negra, with shallow calderas (depth <25% of subaerial height) and slopes that remain <15° until -90% of the total height is reached. Our data show that steep slopes are not uniquely correlated with the occurrence of arcuate fissures at the summit, leaving the origin of the steep slopes unresolved.
Revue / Journal Title
Geophysical research letters
ISSN
0094-8276
CODEN GPRLAJ
Source / Source
1996, vol. 23, n
o25, pp. 3767-3770 (20 ref.)
Langue / Language
Anglais
Editeur / Publisher
American Geophysical Union, Washington, DC, ETATS-UNIS
(1974)
(Revue)
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Localisation / Location
INIST-CNRS, Cote INIST : 16687, 35400006124342.0240
Nº notice refdoc (ud4) : 2526915
