From the TED-Ed Lesson The colossal consequences of supervolcanoes - Alex Gendler
Animation by Andrew Foerster
Mount Sinabung, Indonesia
The world’s newest island
This photo was taken in the past day or two hundreds of kilometers from Japan. Welcome this volcano to the surface, because a few days ago it was beneath the waters of the Pacific.
This island is a volcano popping out of the water 620 kilometers due south from Tokyo. The island is currently about 200 meters wide, is about 500 meters from a currently uninhabited island known as Nishino-shima Island, and sits within the territorial waters of Japan.
These islands are volcanoes formed along part of a long chain of submarine mountains and islands known as the Izu-Bonin arc. The volcanoes are found at this location because of a plate boundary to the east: old sections of the Pacific plate are subducting beneath the Philippine Sea plate. The Izu-Bonin arc and the Izu-Bonin trench both connect directly to the more well-known Mariana arc and Mariana trench to the south; same plates involved, just a different name.
This new island may or may not survive. There are some large, inhabited islands on the volcanic arc produced, but neighboring Nishino-shima Island is not one of them. Right now, the island popping out of the ocean will not be very stable. When lava touches sea-water, it dumps so much heat into the water that the water flashes to steam and explodes, shattering the lava into a mixture of rock shards that we call “hyaloclastite”.
Hyaloclastites are easy to erode since they’re broken pieces of rock; waves can wipe them away. If the eruption goes on long enough, it can start to build an enduring island. For that to happen, stronger rocks will have form on the island. If the island grows big enough for a volcanic peak to form and actual lava flows to cover the surface, those lava flows would stabilize it against erosion by the waves long enough that future eruptions could further enlarge the island.
The nearby island, Nishino-shima, is a volcanic island of this sort, constructed from a series of lava flows built on top of hyaloclastite. In fact, that island is a caldera, a collapse feature, formed when a big volcano empties its magma chamber and then collapses inwards. This new island is probably born from the same magma system that formed Nishino-shima, although the magma has found a new crack to erupt through.
Image credit: Kyodo news/AP
The nearby island:
Thanks to Libby for finding this
Volcano Creates New Island South of Japan
A volcanic eruption has raised an island in the seas to the far south of Tokyo, the Japanese coast guard and earthquake experts say.
Advisories from the coast guard and the Japan Meteorological Agency say the islet is about 200 meters (660 feet) in diameter. It is just off the coast of Nishinoshima, a small, uninhabited island in the Ogasawara chain, which is also known as the Bonin Islands.
Read more: http://www.laboratoryequipment.com/news/2013/11/volcano-creates-new-island-south-japan
North Sumatra, Indonesia | November 21, 2013
Mount Sinabung has had two large eruptions this week including one which saw volcanic ash spewing to a record height of 10km. Thousands of people have been evacuated from their homes until the eruptions settle. Families have taken shelter, some of which are said to have been there since eruptions began in September.
Photos by Ulet Ifansasti/Getty Images
1. A woman wears a mask while work at a coffee plantation in Guru Kinayan village, located just less than three kilometers from Mount Sinabung.
2. A puppy is seen at an abandoned village in Mardinding village, located just less than three kilometers from Mount Sinabung.
3. Villagers gather at a coffee house in Guru Kinayan village, located just less than three kilometers from Mount Sinabung.
4. Children play at their school in Kuta Rakyat village, located just less than five kilometers from Mount Sinabung.
5. A view of an abandoned village in Mardinding village.
6. A dog shelters at an abandoned village in Mardinding village, located just less than three kilometers from Mount Sinabung.
7. A pan covered by ash hangs in an abandoned house in Mardinding village.
8. Alif, one year-old sleeps at a temporary evacuation centre in Tiga Nderket village.
9. A man stands in front of his house at an abandoned village in Mardinding village.
10. An ash covered man works at coffee plantation in Guru Kinayan village, located just less than three kilometers from Mount Sinabung.
There’s been some buzz about a video of a fellow “running up a lava flow.” Normally, Wired Science blogger Erik Klemetti would ignore videos of people doing dumb things, but he realized that although this guy did run up the lava flow, it actually wasn’t as crazy as it seems. DISCLAIMER: This isn’t to say you should ever do what this guy did.