Undersea volcanism
eklemetti | April 3, 2009
Hunga Tonga Hunga Ha'apai, taken in late March 2009
Redoubt did the tried-and-true American trick of shoving news of volcanoes in other parts of the world off the news pages, but shockingly, these international volcanoes continued to erupt. Remember that volcano in Tonga? Hunga Tonga Hunga Ha'aapi? Still erupting, weeks after the volcano was first spotted. The volcano is still disrupting air traffic in and out of Tonga, which is now even affecting the economy of the islands. Now, the problem is that tourists are creeping ever closer to the emerging volcanic island. The thing about visiting…
eklemetti | March 20, 2009
Now that people have been able to get a better look at the are about Hunga Tonga Hunga Ha'apai, we've been able to get a better idea of what sort of eruption occurred. The explosions and ash/tephra from the eruption have all but wiped out life on Hunga Ha'aapai, as the island contains one of the vents, while the other is only 100 meter off shore of the island - although the tephra erupted so far have joined the new vent and the island. You can clearly see ash mixing with the water around the island and the island itself has been blackened by the coating of ash. This is a classic volcanic…
eklemetti | March 19, 2009Mixing volcanoes and oceans seem to always produce exciting results. Whether it is something as simple as the ocean entry of a lava to something as impressive as a new island emerging, formed by volcanic eruption. Back in the 1960s, a previous unknown undersea volcano off the coast of Iceland erupted to form the island of Surtsey. The signs of the impending eruption were captured from start to finish, with Icelandic fisherman noticing "boiling seas", then steam explosions, then ash eruptions and finally volcanic tephra that formed the island itself. This was followed by lava flows and…
eklemetti | March 18, 2009
The eruption of Hunga Tonga Hunga Ha'apai volcano in Tonga looks to be a big one. Keleti Mafi, head of the Tongan geological service, calls this "a very significant eruption, on quite a large scale", which is no surprise considering some of the spectacular picture we saw of the eruption yesterday. In fact, the eruption is big enough that it has disrupted air traffic over Tonga, as Air New Zealand has issued a warning about the ash column - an ash column that has reached over 15,000 meters/50,000 feet! Luckily for the residents of Tongatapu, a mere 10 kilometers 50 km to the southwest SSE…
eklemetti | March 17, 2009
Image from keizo/weblog
Hunga Tonga-Hunga Ha'apai (how's that for a name?), a shallow seamount in Tonga, appears to have erupted. An air passenger snapped some pictures of an eruption occurring in the ocean between the Tongatapu and Vava'u and pilots in the area report that (unsurprisingly), the feature is new.
Hunga Tonga-Hunga Ha'apai - at least the part above water (look in the bottom of the image, the islands are marked in green) - is made of two small islands that cap the main seamount and ring the volcano's caldera. The last known eruption from the volcano was in 1988 - over twenty…
eklemetti | March 12, 2009Two tidbits from New Zealand:
- A recent survey of volcanoes in the Kermadec Arc north of New Zealand suggest that there is abundant - and recent - undersea volcanism. Scientists from University of Washington (one of my former homes) and Southhampton University (UK) explored a number of submarines volcanoes including Rumble II West, Rumble III and Brothers, which are all located along the same arc of volcanoes as New Zealand's own White Island and Mt. Edgecumbe. What they found was a change in the shape of Rumble III (1.4 km below the sea surface) since the last survey in 2007 - the summit…
eklemetti | March 4, 2009
Folks have been suggesting that life on Earth started near volcanic vents for a long time now (and of course, some people don't buy it). Whether or not life sprung forth near hydrothermal vents, undersea black smokers or from the head of Zeus, it doesn't really change the fact that we find organisms living in these places today, expanding what we might consider "habitable" by leaps and bounds. Case and point, researchers from CU-Boulder have recently found a community of micro-organisms happily living near the summit of Volcán Socompa (above) in Chile in the hydrothermal vents. Now, having…
eklemetti | February 11, 2009I get a fairly steady stream of emails from Eruptions readers, some of which are very worth a post, but sometimes it takes me a while to get around to posting. This is my second attempt to catch up on these mailbag emails. Remember, feel free to email me questions or comments whether you want.
Reader Aldo Piombino sent me an email last month after my post on potential Antarctic volcanism asking about some more unknown volcanoes. He brings up Mt. Marsili in the Tyrrhenian Sea (including a post of his own, in Italian), a volcano of which I was not aware. It is a submarine volcano (info on…
eklemetti | February 6, 2009
For those of you interested in what happens in the realm of submarine volcanism, I can pass on some tidbits I've gotten about NW-Rota 1, a submarine volcano in the Mariana Islands (see bathymetry above). Dr. Ed Kohut (Petrogenex), a friend of mine from my days at Oregon State Univ., is currently on a JAMSTEC research cruise in the Mariana Islands, visiting the area about NW Rota-1. He reports:
"We just reached NW-Rota 1. It is still actively erupting. To put that in perspective, it has been observed erupting every time it has been visited since 2003. Today's actvity is not as vigourous as…
eklemetti | September 25, 2008
This might not be directly related to a volcanic eruption, but it has been picked up by a lot of news sources, so I thought I'd give it a mention. A report from researchers at University of Texas hypothesize that some very large coral boulders (up to 10 meters tall) that can be found on the shores of Tongatapu are, in fact, tsunami deposits. That is news enough, but they go on to say that the tsunami could have been volcanically triggered (i.e., started by an eruption or volcanic landslide). The corals are ~122,000 years old and a soil has formed on the corals, so the event was likely…
eklemetti | June 19, 2008
The western Pacific basin is pockmarked with active and extinct volcanoes related to the subduction of the Pacific plate along almost all of its western boundary. An Australian National University research group recently discovered a pair of undersea volcanoes that would put any good mining geologist into a fit of joy. These volcanoes are spewing volcanic gases underwater that are very rich in metals like copper, lead, zinc and gold. All of these metals like to go into solution in acidic fluids like volcanic gases, and when these volcanic fluids meet the cold (and decidedly less acidic)…
eklemetti | June 12, 2008
Most people don't realize that a majority of the earth's volcanoes are underwater. That is to say, the mid-ocean ridge system that runs along the bottom of all the major oceans can be considered one big volcano. However, thanks to its location deep underwater, we have only had second- or third-hand evidence of eruptions at mid-ocean ridges or seamounts.
Not any longer according to my graduate alma mater, Oregon State University. An active eruption was captured at Brimstone Pit in 2006, near Guam, by a team looking for hydrothermal activity at the sea's bottom. The eruption appears to be a…