When searching the virtual-Earth for a hiding place, I often start by seeking out arcs of volcanoes, knowing those will be the most likely places to find a volcano with a lively eruptive history or at least some interesting topography. But sometimes a volcano stands out from the rest, away from the herd, a one-off… and I can relate to that. That is how I found this week’s volcano, the only magmatically active volcano in what would seem like a fertile spot for volcanism, in the Andaman Sea, 1,500 km off the east coast of its patron country of India..an aptly-named volcanic island called Barren Island.
The active cone in the center of the 3 m wide island is around 264 m high, but is partially surrounded by a caldera which rises to 355 m at its highest point on the southern rim. However, if measured from the sea floor, the island would have an elevation of 2,250 m. The somma caldera, which was produced by a large explosive eruption in the late Pleistocene, is about 1.6 km wide rim-to-rim and is open to the west.
The Barren Island volcano is a product of the subduction of the oceanic crust of the Indian Plate beneath the Burma Microplate, forming the Andaman and Nicobar Islands. an island arc that stretches between Myanmar (Burma) and Sumatra and also includes many inactive submarine volcanoes.. Prior to formation of the modern caldera, the ancestral stratovolcano had seven major eruptions, the first at around 70 million years ago and the last just 10 million years ago. More recently (geologically speaking) it has had 13 confirmed Holocene eruptions, 11 of which were historically observed. Most of Barren’s eruptions have been VEI 2 of a mildly explosive nature, often changing the morphology of the central cinder cone and producing lava that fills the caldera floor and flows west into the sea. As for the island’s name, it has always been rather remote and inhospitable to living things, but there are only low-growing plants and a handful of species of birds and small animals to be found there when the volcano is active.
Barren Island’s eruptions do not always come at regular intervals. This volcano loves a good nap. Prior to his 1 April 1991 eruption, he had been dormant for 159 years. One has to wonder if first reports of the new activity might have at first been thouight to be an April Fools prank. That eruption continued until late October, but more eruptive periods followed in 1994, 2000, 2005, 2008, 2010, early 2013 and a final eruption with a start-date in late 2013 that is reported as ongoing. His early 2005 eruption is likely associated with the Sumatra-Andaman Earthquake that caused the Boxing Day Tsunami of 2004.
Below is a video showing seismic and volcanic activity around Barren Island beginning just before the volcano reawakened. The blue circles represent earthquakes, the larger, the more powerful. Global Volcanism Program’s s E3 web app is a graphic timelapse map of earthquakes, eruptions and emissions around the world since 1960
His current status is a developing story at this time. New (or presumed new) activity was discovered quite by chance on 23 January 2017 by a team of scientists from India’s National Institute of Oceanography, where their ship was collecting seafloor samples in the Andaman Basin east of the island. They reported short bursts of activity lasting 5-10 minutes. During the day only ash was visible but at night fountaining lava and flows were observed. The ship returned three days later and verified the eruption was ongoing. While there, they collected some black coal-like samples of pyroclastic material for further analysis.
Without remote observation equipment on the island, and otherwise relying solely on chance visual observation by passing ships or planes, the chronology of Barren Island’s eruptive activity is based upon thermal anomalies observed from orbit. MODVOLC and MIROVA images may yet determine exactly when the 12 October 2013 eruption actually ended or if January 2017’s activity is part of that episode.
The following video is in Hindi language, but includes some amazing video and still images of the volcano in action as well as some epic volcano-worthy music.
But I wanted to do my own tribute to Barren Island. I’m no Pixar, but I try. Enjoy!
It looks like Glenn was the only one to find me this week, and I apologize to Granyia for the accidental spoiler in the comments. Hopefully it will not happen again. And now it is time for me to make my escape again. Come find me again this coming Monday on a new adventure at a new volcano.