Renewed Eruptions at El Hierro in the Canary Islands
- By Erik Klemetti
- November 5, 2011 |
- 1:09 pm |
- Categories: Eruptions, Science Blogs
Renewed submarine volcanism off the southern coast of El Hierro, as seen on November 5, 2011. Image courtesy of IGN.es
Trying to keep up with the news at El Hierro in the Canary Islands is hard – the seismicity and tremor has been almost nonstop for 6 months now and over the last few weeks, the submarine eruptions have waxed and waned – but now we seem to have entered another period of strong submarine activity (see above), which might possibly be closer to the ocean surface.
UPDATE 3:15 EDT: It looks like the phreatomagmatic explosive activity is beginning south of El Hierro. Prensa El Hierro tweeted (translated): “Juan Manuel Santana have just announced that produce water columns and ash.” La Restinga is being evacuated as a precaution. Some new video/images of the areashows small explosive plumes/jets from the ocean surface that suggest the eruption is enterting aSurtseyan phase. Here is a live feed of TV from El Hierro with updates.
Another view of the new activity from La Provincia – the article claims material was ejected as high as 20 meter.
- Another view of the beginning of the explosive phase of the eruption at El Hierro on November 5, 2011. Image from La Provincia.
The linear set of vents for the current El Hierro submarine eruption, as seen on November 5, 2011. Image courtesy of IGN.es.
The current activity is pretty clear from a linear vent on the seafloor (see right) and there are very prominent bubbling areas where the volcanic tephra and gases are rising – with some excellent video to show that activity. This vent, as I’ve mentioned before, is likely to be very similar to what we see at Kilauea during new fissure vent eruptions – albeit that this one is under the sea. At the depths that the material is eruption (few hundred meters), the eruption is likely not highly explosive but plenty of shattered basaltic (or basanitic) glass is being produced as the lava hits the cold ocean water.
Now, it does appear that the bubbling is more intense (video) – and more of it – so if these vents do begin to get close enough to the surface to produce ocean-surface explosions, we might expect something like the 2009 Hunga Tonga Hunga Ha’apai activity, also know as Surtseyan eruption. There has been more of the floating, dark pyroclastic material (see below) as well from the renewed activity at El Hierro.
Now, it does appear that the bubbling is more intense (video) – and more of it – so if these vents do begin to get close enough to the surface to produce ocean-surface explosions, we might expect something like the 2009 Hunga Tonga Hunga Ha’apai activity, also know as Surtseyan eruption. There has been more of the floating, dark pyroclastic material (see below) as well from the renewed activity at El Hierro.
All of this new activity has prompted the PEVOLCA to indefinitely close the tunnel to Frontera after earthquakes as large as M4.4 have occurred on El Hierro. New evacuations have also been called for people living on the southern end of the island due to the renewed eruptive activity.
Erupted pyroclastic material from El Hierro on the surface of the ocean, as seen on November 5, 2011. Image courtesy of IGN.es.
The tremor continues underneath El Hierro, so we haven’t likely seen anything close to the end for this eruption.
{Special thanks to @suw, @lumifg, @teideano, @rschott amongst others for information/images in this post.}
Erik Klemetti is an assistant professor of Geosciences at Denison University. His passion in geology is volcanoes, and he has studied them all over the world. You can follow Erik on Twitter, where you'll get volcano news and the occasional baseball comment.
Follow @eruptionsblog on Twitter.
Follow @eruptionsblog on Twitter.
http://www.wired.com/wiredscience/2011/11/renewed-eruptions-at-el-hierro-in-the-canary-islands/
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