Alcedo Volcano
Updated: 24 avril. 2024 13:07 GMT -
Shield volcano 1130 m / 3,707 ft
Galápagos Islands, Ecuador, -0.43°S / -91.12°W
Condition actuelle: normal / en sommeil (1 sur 5)
Galápagos Islands, Ecuador, -0.43°S / -91.12°W
Condition actuelle: normal / en sommeil (1 sur 5)
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Eruptions du volcan Alcedo: 1993
Derniers séismes proches
Heure | Mag. / Profondeur | Distance / Lieu |
Introduction
Alcedo is one of the lowest and smallest of six shield volcanoes on Isabela Island. Much of the flanks and summit caldera are vegetated, but young lava flows are prominent on the northern flank near the saddle with Darwin volcano. Alcedo is the only Galápagos volcano known to have erupted rhyolite as well as basalt, producing about 1 cu km of late-Pleistocene rhyolitic tephra and lava flows from several vents late in its history. Recent faulting has produced a moat around part of the 7-8 km caldera floor, which is elongated N-S and appears to be migrating to the south. Fewer circumferential fissures occur on Alcedo than on other western Galápagos volcanoes. An eruption attributed to Alcedo in 1954 (Richards, 1957) is more likely to have been from neighboring Sierra Negra (Simkin 1980, pers. comm.). Photo-geologic mapping of Alcedo by K. A. Howard (pers. comm.) revealed only one flow on October 30, 1960 photographs that does not appear on May 30, 1946 photos. That is near Cartago Bay, low on the SE flank, rather than the 610-m, NE-flank elevation listed for the 1954 eruption. An active hydrothermal system is located within the caldera.---
Smithsonian / GVP volcano information