Monday, December 19, 2011

Eruptive Activity Continues At El Hierro At Low Rate

The eruption, contrary to my previous report, is ongoing at El Hierro, although at a much reduced level. The 'stain' on the oceans surface is still visible on and off during the day, although my last check on the webcam showed zero activity on the ocean's surface. Pictures from INVOLCAN showed a much smaller stain on the water than at previous times, and the stain has also moved further WSW. This has led some to speculate whether or not the same vent is responsible for the discoloration, however INVOLCAN states that it is the same vent, and the stain being further is a result of stronger currents.

Tremor has continued at a much lower level than previously, but has not gone away. This leads me to believe that magma could still be (slowly) on the move. It is possible for the vent to re-pressurize and explode again, however the trend with this eruption indicates that it is slowly ending. It is always possible that another vent could open up, but at this stage it is impossible to tell whether or not this will occur.


The Eruption continues at a low level. Webcam views from this morning clearly indicate a dynamic and changing situation underwater, with two to three separate, but small, 'stains' visible on time lapse camera from The stains slowly 'migrate' from right to left, against the current, so I don't think that the eruptive activity is weak enough (as previously suggested) to be affected much by the currents. This could indicate that the main vent has collapsed, shoving magma pressure further down to the foot of the vent, resulting in several small side fissures that open and close at random. This would explain why the stains appear to 'move'.

Harmonic tremor is weak, and despite small fluctuations, the trend still looks as if the eruption is beginning to subside. It is still possible for other areas to erupt, as previously noted, the thousands upon thousands of quakes preceding this event paint a picture of a large magma chamber, perhaps two. The majority of volcanic quakes were not located under La Restinga, those quakes occurred with a second smaller swarm. After reviewing previous data, it is my opinion El Hierro could be in for much more... but time will certainly tell,  and I do not want to be the guy that hypes the eruption up to be something it's not.

If anything new develops, you'll hear about it here!

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