Sierra Negre volcano news & eruption updates (Galapagos Islands, Ecuador)
Sierra Negra volcano (Galapagos): continuing activity, eruption update
Wednesday Sep 05, 2018 12:05 PM | BY: TIG reported that the eruption at Sierra Negra that began on 26 June was divided into two main phases.
The first and most energetic phase lasted one day (26 June) and was characterized by the opening of five fissures and lava flows traveling as far as 7 km from the vents. Lava was only produced from fissure 4 during the 57-day-long second phase (27 June-23 August), with lava reaching the sea on 6 July and expanding the coastline.
By 25 August the lava flows in total covered an area of 30.6 square kilometers. Activity continued to decline the last week of August with decreased seismicity, gas emission, and no superficial activity visible.
Wednesday, Jun 27, 2018
Sierra Negra volcano (Isabela Island, Galapagos) activity update: fissure eruption with fountaining and lava flows
Wednesday, Jun 27, 2018
Sierra Negra volcano (Galapagos): strong earthquakes precede the start of a first fissure eruption since 2005
After two prolonged seismic crises with earthquakes up to M5.3, the Sierra Negra volcano entered a new eruptive phase with strong fountaining and multiple lava flows on Tuesday 26 June 2018 - the first volcanic activity since its last eruption in 2005. ... read all
Thursday, Jun 14, 2018
Sierra Negra volcano (Galapagos): increased seismic activity and strong deformation, eruption warning
A seismic crisis has started under the volcano recently, suggesting that the volcano could be approaching a new eruption in the near or medium-term future (weeks to months). ... read all
Monday, Nov 14, 2005
Lava stopped flowing at Sierra Negre volcano on the evening of 30th of Oct. 2005.However, even 10 days after the end of the eruption, fires caused by the eruption continued, threatening some rare plants on the island. About 500 hectars in the National Park were burning on the W flank of the volcano in an area called Pampas de Velasco. This area is home to the largest population in the islands of the rare endemic plant Scalesia cordata, which was threatened by the fires. Therefore, the local authorities decided to intervene and take costly measures to extinguish the bushfire. ... read all
Saturday, Oct 29, 2005
The eruption of Sierra Negre continues with lava flows confined to the vast caldera; it does not pose risks to populated areas. In the meanwhile, a group of scientists from the Geophysical Institute of Ecuador have visited the site and posted a detailed report about the eruption's first 3 days: it can be downloaded here. ... read all
Eruption of Sierra Negre volcano (23 Oct. 2005):
(free translation of text in image:)
Graphic showing the location of Sierra Negre and the evolution of the eruption of 23 Oct. 2005, published by the newspaper "El Universo". (Free) translation below:
What is nearby? Near the eruption site, the terrain consists mainly of older, unvegetated lava flows. The popoluation of Puerto Villamil is not threatened becaused of its sheltered location at the S of the island. Because of the geologic characteristics (being a typical hot spot volcano, such as Hawaii), the volcanos of the Galapagos Islands produce very fluid lava flows (low viscosity) that permits the flows to travel over great distances.
Evolution of the eruption:
1) The eruption began, at 17:30 h local time on Sunday, 23 Oct. 2005, with a powerful explosion that emptied the uppermost batch of gas-charged magma, heard until 25 km away from the volcano. In addition to the noise of the explosion, a strong smell of sulphur was notised.
2) A gas and ash column rose to about 20 km above the volcano.
3) From a fissure (inferred from photographs), lava fountains started to produce lava flows observed by park rangers. Two flows are travelling towards Elizabeth Bay, while a third one is heading towards Cartago Bay. The lava flows (as on Mon. 24th of Oct.) have reached a distance of 9-10 km.
Backgound: Sierra Negre is the largest of the Galapagos volcanoes, with a caldera 10 km in diameter. Its last eruptino occurred in 1979; the lava flows of that eruption did not pose any significant risk to the population of the island.