Wednesday, May 27, 2015

Galapagos Wolf Volcano Erupts For First Time In 33 Years

The volcanoes of Galapagos have been quiet for a while but that quiet has been ended by a spectacular eruption of Galapagos' Wolf Island Volcano. From images it appears a flank fissure has opened up outside the caldera, issuing fluid pahoeoe lava flows (much in the same style of Hawaiian volcanoes). According to VolcanoDiscovery.com, no wildlife, especially the famed pink iguanas, are threatened by the flowing lava.


Google Earth screenshot showing Wolf Volcano in the Galapagos.


Image taken from boat of Wolf volcano on May 25, 2015

Lava fountains issuing from the fissure are visible in most images. The Smithsonian GVP reports on Wolf volcano:

"According to IG the seismic station located on Fernandina Island recorded several events at Wolf (on Isabela Island) starting at 2350 on 24 May. The most significant signal occurred at 0058 on 25 May, corresponding to an explosion and the start of an eruption. At 0215 the Washington VAAC detected an ash plume that rose to an altitude of 10.7 km (35,000 ft) a.s.l. and drifted 65 km SW. At 0345 one ash plume drifted 250 km ENE at an altitude of 15.2 km (50,000 ft) a.s.l., and another drifted 250 km S at an altitude of 13.7 km (45,000 ft) a.s.l. Starting at 0428 the Hawai'i Institute of Geophysics and Planetology (HIGP) reported intense thermal anomalies on Wolf's SE flank based on MODIS satellite data. Galapagos National Park staff reported an arcuate fissure along the upper SSE rim and several lava flows descending the flanks. Later that day the VAAC noted a smaller ash emission that drifted 150 km SW, and a bright thermal anomaly that had persisted. Satellites detecting sulfur dioxide showed that the cloud was sulfur-dioxide rich and ash poor; ~100-200 kt of sulfur dioxide had been emitted during the first 13 hours of the eruption."

They further characterize it here:

"Wolf, the highest volcano of the Galápagos Islands, straddles the equator at the north end of the archipelago's largest island, Isabela. The 1710-m-high edifice has steeper slopes than most other Isabela volcanoes, reaching angles up to 35 degrees. A 6 x 7 km caldera, at 700 m one of the deepest of the Galápagos Islands, is located at the summit. A prominent bench on the west side of the caldera rises 450 above the caldera floor, much of which is covered by a lava flow erupted in 1982. Radial fissures concentrated along diffuse rift zones extend down the north, NW, and SE flanks, and submarine vents lie beyond the north and NW fissures. Similar unvegetated flows originating from a circumferential chain of spatter and scoria cones on the eastern caldera rim drape the forested flanks to the sea. The proportion of aa lava flows at Volcán Wolf exceeds that of other Galápagos volcanoes. An eruption in in 1797 was the first documented historical eruption in the Galápagos Islands."


It is likely the eruption will continue for some time. If anything major changes, I will update this post. Until then, enjoy the various photos that are sure to emerge! The eruption is a beautiful example of a Galapagos volcanic episode!

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