Sierra Negra Volcano
Updated: Apr 29, 2024 09:19 GMT -
shield volcano 1124 m / 3687 ft
Isabela Island, Galapagos, -0.83°S / -91.17°W
Current status: normal or dormant (1 out of 5)
Isabela Island, Galapagos, -0.83°S / -91.17°W
Current status: normal or dormant (1 out of 5)
Last update: 13 Dec 2021
Sierra Negra is one of the largest and most active volcanoes in the Galapagos Islands. A typical shield volcano, it has an oval caldera, which measures 9 km east-west and 7 km north-south. It has produced at least 10 eruptions in historical times, with an average resting period of only 15 years between each eruptive period.
The last two eruptions occurred in 1979 and 2005 (as of early 2018).
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Sierra Negra volcano eruptions: 2018 (June-Aug), 2005 (Oct), 1979-80, 1963, 1957, 1954, 1953, 1948, 1911, 1860, 1844, 1817, 1813, 1350 ± 500 years, 1060 ± 500 years, 370 AD ± 1100 years, 1250 BC ± 100 years, 8250 BCE ± 1600 years
Latest nearby earthquakes
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Background
The broad shield volcano of Sierra Negra at the southern end of Isabela Island contains a shallow 7 x 10.5 km caldera that is the largest in the Galápagos Islands. Flank vents abound, including cinder cones and spatter cones concentrated along an ENE-trending rift system and tuff cones along the coast and forming offshore islands.The 1124-m-high volcano is elongated in a NE direction. Although it is the largest of the five major Isabela volcanoes, it has the flattest slopes, averaging less than 5 degrees and diminishing to 2 degrees near the coast. A sinuous 14-km-long, N-S-trending ridge occupies the west part of the caldera floor, which lies only about 100 m below its rim. Volcán de Azufre, the largest fumarolic area in the Galápagos Islands, lies within a graben between this ridge and the west caldera wall.
Lava flows from a major eruption in 1979 extend all the way to the north coast from circumferential fissure vents on the upper northern flank. Sierra Negra, along with Cerro Azul and Volcán Wolf, is one of the most active of Isabela Island volcanoes.
Source: GVP
Sierra Negra Volcano Photos
Sierra Negra Volcano (Tliltepetl, 4640m), Citlaltepetl in clouds (in right corner), near Orizaba, Mexico (Photo: WNomad)
Eruptions of Sierra Negra volcano
June-Aug 2018 eruption
After one year of significant unrest, a large fissure eruption started on 26 June 2018, involving the formation of lava fountains and large lava flows on the northern flank of the volcano. Lava flows enlarged the northern coastline of the southern part of the island. ...more info
After one year of significant unrest, a large fissure eruption started on 26 June 2018, involving the formation of lava fountains and large lava flows on the northern flank of the volcano. Lava flows enlarged the northern coastline of the southern part of the island. ...more info