Continued activity at El Hierro

Since the last post has grown somewhat ‘large’, I thought I could better create a new post with some updated information, and less than about 600 (!) comments to scroll by. Because the last post (and the comments section) was really full with excellent links, I will start off by providing the link to the previous post:

https://volcanocafe.wordpress.com/2013/03/22/keeping-a-close-eye-on-el-hierro-and-ntv-riddle/

Several commenters have mentioned that the period between the flare-ups of earthquake activity has been steadily increasing, and that the intensity of the earthquakes has been increasing as well. Below is the tremor graph of today, which shows a phase of intense quaking/shaking just after midnight and another phase this afternoon, which produced the largest EQ of this renewed activity yet at M4.1

Tremor graph published by the IGN.

harrie has mentioned that over the last few days a clear trend in EQ’s could be seen, translating to a general westward and upward movement of the ‘active front’ where the quakes were generated. However, this afternoon he mentioned that this upward trend of EQ’s has stopped since about 100 listed EQ’s ago, while the trend of more intense EQ’s with time has not. This might mean that the mechanism that has been seen by many as being the growth of a sill, has come to a stop, while the magma flow has not. This could mean a hard stop has been reached, while pressure is now slowly rising in the system, looking for a way out in another direction, which might be directly upward through one of the many pre-existing-but-inactive dikes/conduits below El Hierro.

KarenZ mentioned that AVCAN has posted a warning on their Facebook page, stating that El Hierro inhabitants should keep an eye on the TV and an ear to the radio to be sure not to miss anything if official sources issue a warning, or other critical information.

Vulcanoelhierro.es (in Spanish) has published an article stating that so far nothing abnormal has been sighted while performing acoustic depth measurements to detect anomalies at the seafloor which might indicate the activity has reached the ocean floor. Sissel, an earthquake-report reader is being mentioned by earthquake-report.com for providing an image of the cruising traject of the ship. There it is also mentioned that INVOLCAN has sent in a team to reinforce measuring systems, and to measure CO2 as well.

Image by earthquake-report.com

On the other hand, the deformation is still ongoing. In fact, the scale had to be adjusted to still be able to see the deformation at the Sabinosa station. Below is the deformation image, for all to draw their own conclusion…

Sabinosa up-down GPS deformation. Image by IGN.

Sabinosa east-west GPS deformation. Image by IGN.

Let’s also not forget dfm‘s rotating 3D plots which show the earthquakes in time-lapse mode, projected with the El Hierro geography, with an explanation in his comment. I will try to keep this one updated if he decides to post a new one with updated data as time progresses.

And last but not least….

I would also like to point to some of Kilgharrah‘s ‘Name those Volcano’ riddles. Only one has been solved so far, so lots of opportunities for a volcanophile to rise on the volcanophile-list-of-fame (currently dominated by Alison and several other women) remain for all!.

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Name those Volcanoes Riddle

Note – this weeks riddle is a little different …. In order to identify each volcano you have to establish a link (some are more tenuous than others) between the volcano and various classifications, dates, places, events, people etc …. each clue has three genuine links and one ‘red herring’ included!

1 point for each correct volcano and 1 point for each ‘red herring’ (which must be identified with an explanation) guesses wont count ….. good luck!

No 1 – Lord Byron’s wife ; November 5th 2013 – Australian sporting event; Lethal mud slides; Pacific Ring of Fire; SOLVED

No 2 – Stratovolcano; Canada; Formula 1 Team; Angels – song; SOLVED

No 3 – Stromatolites; 40,000; Rain forest; UNESCO; SOLVED

No 4 – UK; Dormant; Summer Rain – song; Vintage Car Museum owner; SOLVED

Hints: ‘red herrings’ are now marked in bold! I have added to the clues as well to help get them solved!

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El Nathan

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423 thoughts on “Continued activity at El Hierro

  1. So, while watching the webcam for Hekla, looking at football (Ned-Roe; 1:0 12′), I was playing with some numbers from El Hierro again. First of all, the scaling down again seems obvious. Despite the lower signal, the average intensity of the EQs is only slightly reduced during the last day. Furthermore, the average depth remains at approx. 15 km at the moment but still with a trend to go slightly more shallow. The strange thing is that the EQ intervals stays rather short (also showing that the down scale is in effect). So, is this indicating that no large breaking is possible any more without a major jump, and that the current EQs pinpoints the last remaining possibilities for the magma to expand.. or are we just waiting for the next bolus to arrive for the next push.
    (as for many of us, I am just an observer, trying to be an amateur)

  2. Thanks @ Kilgharrah for getting my entry in the great Hekla 2012 prediction sweepstake 😀
    How I love this Blog. Serious stuff tempered by light hearted good humour. I really can’t see much change in Hekla’s signals right now but she is such a fast mover all hell can break loose within minutes.
    Irpsit we have your weather. It’s been snowing lightly all day and is bitterly cold. I need one of your lovely Icelandic sweaters. 😀

  3. Here is a plot of Hekla´s local earthquakes from 2000 until today (view from NE).

    The last two earthquakes from the listi were on Mar 21st and 23rd and were located in the small group at 10 km depth, here facing West:

    The bulk of blue events occured on the day of the last eruption Feb 26, 2000.
    The depth axis is compressed about 2x in order to get the Moho layer (http://www.seismo.helsinki.fi/mohomap/) into view. The topology is from geodas-design-a-grid.

  4. Uh, I have completely forgot how bad weather looks like after a loooooooooooooong time with sunshine here in western Norway. Seems that we will get the dryest march in 49 years.(Only 15-16 mm so fare. Looks like we will have sun for a long time yet, but it would certainly be nice with some rain now. Has been to much grass fires the last 14 days.

  5. I think we should appreciate the achievement of the IGN-staff! All data are available, very good web-site, nearly ever available! What a difference to former times! Great job!

  6. Pingback: Iceland Civil Protection Service has declared “uncertainty phase” at Mount Hekla! | Secret Code

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