Time to catch up on some of the volcanic action from around the planet -- a lot has been going on, with some volcanoes ramping up activity (Ambrym) and some slowing down (Holuhraun). This week, almost all the updates are accompanied by a fairly recent shot take from one of the constellation of Earth-observing satellites out there, so enjoy! Ambrym
Ambrym in Vanuatu, with a steam-and-gas plume obscuring a new eruption that opened a new vent in the Marum crater. Image taken February 21, 2015 via Terra's MODIS imager. Photo: NASA. The Marum crater of Vanuatu's Ambrym has been home to a lava lake for many years. It is a spot where adventurers and scientists alike go to get up close and personal with an actively erupting volcano -- as can be seen in recent drone footage and descriptions from a group including Dr. Jeff Marlowe. They are looking at the Ambrym lava lake area as a great place to find extremophile life that live in places we might not expect. Over this past week, the eruption at Ambrym became more vigorous and a new vent opened in the crater, creating one of the first lava flows in the crater in decades. The Terra image taken on February 21 shows the white plume above the island (marked with an arrow). This plume is water vapor, sulfur dioxide, carbon dioxide and more being released in the eruption. Karymsky
The wispy plume from Karymsky in Russia, seen on February 27, 2015 via Terra/MODIS. Photo: NASA. We would know something strange was afoot if we didn't have so much volcanic activity in Kamchatka. The Terra image (above) shows the typical grey-brown plume of ash from Karymsky. The Russian volcano has been on orange alert status perennially, with occasional larger explosions punctuating an almost constant stream of ash. Holuhraun
The country of Iceland, seen on February 21 via the Terra MODIS image. The dark smudge in the middle is the Holuhraun eruption. Photo: NASA. Meanwhile, in Iceland, the endgame for the Holuhraun eruption may have begun. Over the last few days, the number and size of earthquakes in the area has dropped dramatically, with no M3 or greater earthquakes in the past 48 hours. Deflation is continuing under the Barðarbunga caldera, suggesting magma is still moving from under the caldera to the active vents. However, the reduction in earthquakes might mean that the input of new magma from below is subsiding. The eruption of lava at the main vent has also slowed, but this seemingly good news hasn't stopped some Icelandic volcanologists from saying that something worse (an eruption at Barðarbunga) could still be in the cards. Chikurachki
The ash from a brief explosion at Chikurachki drifting over the sea, with another small plume over the volcano to the east (right). Image taken February 16, 2015 by Terra's MODIS Imager. Photo: NASA. Further south from the Kamchatka Peninsula lie the Kuril Islands, most of which are active volcanic islands. Chikurachki has been restless lately and this week it produced ash plumes that reached 8 km (~26,000 feet) above sea level. Paramushir Island is sparsely populated (at best) so the real hazard from such a volcano is the danger to air travel across the Kuril Islands. Sakurajima and Aso
Sakurajima producing a small plume (bottom) with the Aso caldera quiet (top, in reddish area). Image taken February 20, 2015 by Terra's MODIS Imager. Photo: NASA.Sakurajima and Aso also illustrate the potential dangers of volcanoes to air travel. In this February 20 Terra image, a small plume can be spotted coming from Sakurajima while its northern neighbor, Aso, is quiet. However, you can also spot some contrails from aircraft criss-crossing this volcanic area, showing how a large eruption from either of these volcanoes would not only imperil the people nearby but also the commercial traffic across southern Japan. Colima
A Landsat 8 OLI image of an eruption of Colima in Mexico, seen on February 8, 2015. Photo: NASA Earth Observatory.Colima has been especially restless during the month of February. The explosions from this Mexican volcano have been larger than what has been typical for the past few years, now regularly reaching 6-7 km (19-20,000 feet). There is some cool webcam footage of some of these explosions that shows how the volcano will build pressure under the main summit vent and then release it in a fit of explosivity that is powerful but brief. Check out the Colima webcam for yourself to see if you can catch one of these explosions. Kliuchevskoi
A small plume from Kamchatka's Kliuchevskoi, seen on February 25, 2015 via Aqua/MODIS. Photo: NASA Another day, another ash plume in Kamchatka, this time from Kliuchevskoi. This Russian volcano also has an active lava flow on its eastern slopes. Nyiragonga and Nyamuragira
A Landsat 8 OLI image of Nyiragongo (bottom) and Nyamuragira (top) in the DR Congo, taken on February 9, 2015. Photo: NASA Earth Observatory. The most persistently active volcanoes in Africa are the twin shields in the Congo, Nyiragongo and Nyamuragira. Both have lava lakes at their summit and both release a constant sulfur dioxide-rich plume. What I like about this recent Landsat 8 image of the volcanoes how clearly it shows one of the inactive craters on both volcanoes, betraying how the source of eruption has shifted many times during the history of these volcanoes. Nishinoshima
A view from a Japan Coast Guard helicopter of the current eruption at Nishinoshima. Photo: Japan Coast Guard. The last volcano doesn't have a shot from space, but rather from much closer to the ground (namely: Japan Coast Guard helicopter footage). The eruption at Nishinoshima has been going strong now for well over a year and the island itself is entirely dark basaltic lava flows with a perfect ~100 meter-tall cone just offset from the middle of the volcano. This eruption has been a textbook example of how volcanic islands grow, with the island now covered ~2.5 square kilometers. Check out this video taken by the Japan Coast Guard of an overflight of the growing island.
