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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, no25, pp. 3767-3770 (20 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Geophysical Union, Washington, DC, ETATS-UNIS  (1974) (Revue)

Mots-clés anglais / English Keywords

Galapagos Islands

;

slopes

;

volcanoes

;

interferometry

;

radar methods

;

airborne methods

;

basaltic composition

;

synthetic aperture radar

;

accuracy

;

high resolution

;

topography

;

geomorphology

;

calderas

;

fissures

;

arcuate faults

;

East Pacific Ocean Islands

;

Mots-clés français / French Keywords

Iles Galapagos

;

Versant

;

Volcan

;

Interférométrie

;

Méthode radar

;

Méthode aéroportée

;

Composition basaltique

;

Radar antenne synthétique

;

Précision

;

Haute résolution

;

Topographie

;

Géomorphologie

;

Caldeira

;

Fissure

;

Faille arquée

;

TOPSAR

;

Radar imageur synthèse ouverture

;

Sierra Negra

;

Wolf

;

Fernandina

;

Cerro Azul

;

Darwin

;

Alcedo

;

Iles Océan Pacifique Est

;

Mots-clés espagnols / Spanish Keywords

Declive

;

Volcán

;

Interferometría

;

Radar

;

Método aerotransportado

;

Composición basáltica

;

Precisión

;

Alta resolucion

;

Topografía

;

Geomorfología

;

Caldera

;

Fisura

;

Falla arqueada

;

Localisation / Location

INIST-CNRS, Cote INIST : 16687, 35400006124342.0240

Nº notice refdoc (ud4) : 2526915



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