El Hierro and the art of Bad Science

The first of the phreatomagmatic explotions that was caught on a picture back when the eruption was going at a much higher rate than today. It was most likely not a real phreatomagmatic explosion, it was more likely to have been a combination together with a massive gas release. But this is what will be in store most likely for the residents of La Restinga.

After releasing the sixth missive that volcanic vent affectionately known as Bob is dead, the authorities have now finished the monitoring of the volcano.

This declaration of cessation of activity is contrary to all known data. All released data point towards that the volcanic edifice is still growing at a rate of 10 to 15 meters per 2 weeks. There is still harmonic tremor associated with new magma arriving into the volcanic system from the deep. There was a steady and visible disturbance over the volcanic vent, and the gas-measurements are still above normal readings.

Instead of happily following what is happening the authorities have decided to shut down the web cameras, discontinue active monitoring, abandoning bathymetric scans of the volcanic edifice, and generally trying to hide that there is a volcano on the island of El Hierro.

This is most likely done due to political pressure to achieve a former state of touristic bliss, since it does not have any good scientific foundation.  The responsible organizations have instead chosen to only rely on data that supports cessation, disregarding contrary factual information. This is the Popperian “Art of Bad Science”.

Only problem here is that soon Bob will be hitting the threshold of where hydro magmatic activity will be clearly visible on the surface. Something that was caught on video a couple of days ago by our commentators in here. This activity will only grow during the upcoming weeks.

In 2 to 4 weeks the authorities will most likely have a set of rather distraught residents at La Restinga as they start to see ‘rooster-tail’ explosions surfacing on top of Bob. If activities then continue we are somewhere around 14 to 20 weeks before the volcano surfaces.

Now somebody with a bit of math skill will say, “What? It grows with more than five meters per week! It should be up faster”. Not really, this is due to a cone needing more material to grow, the higher it get. So, the speed of growing in height will decrease over time.

The authorities are probably betting/hoping that the eruption will finish within the next few weeks and save their collective behinds. Sadly they will just then issue a proclamation that the volcano have “re-awakened” to save them.

I am sadly reminded of George Orwell’s 1984, where the author describes “newspeak”, where the meaning of words changes as the powers that be see fit. I never thought I would see scientists involved in the Newspeak of Volcanoes.

I feel very much for the poor residents of La Restinga that in a short time will be scared uselessly and without cause out of scientists running the errands of political buffoons.

CARL

El Hierro – Survival of a stubborn Volcano

Image by IEO. Here we can clearly see the vents of Bob.

Life normally is filled with patterns. El Hierro has a pattern of its own, IGN declares the volcanic vent affectionately named Bob as dead, and a couple of days later the scientific crew of the ship Ramon Margalef publishes a report proving them wrong.

This time in addition to the bathymetric data we also got acidity values and electrical conductivity curves. The interesting thing with these is that they prove that during the measurement period there was a point source feeding acidic compounds into the water. The most likely culprits for the acidity are sulphuric acid and CO2. The values are still roughly the same as during the last measurements was taken, and this leads to the obvious conclusion that the vent is open and active. Also the electrical conductivity is pointing to an active source changing the conductivity.

The bathymetry gives at hand that the cone has now reached 88 meters from the surface. This gives that the growth rate during the last month has been 36 meters. At the going rate we should start to see surface disturbances in about two to four week as hydro magmatic explosions start.

Also noteworthy is that the shape of the volcanic main vent has changed from the stratovolcanic type with steep angle of slopes, to a shallower angled shield volcano type (26 to 33 degrees). One should though remember that a sub-aquatic volcano always has steeper angles compared to a sub-aerial one. This due to the water cooling the lava faster than the air does.

Image by IEO. Here we can see how shallow the angles of Bob have become during the last couple of months. The true angle is now between 26 and 33 degrees, normal angle for a sub-aquatic shield volcano constructed from unevolved basalts.

Another tidbit given is that the lava now is more fluid then before. This goes well with the less steep angles that we see now.  It all points towards that the first phase of eruption was containing large parts of reactivated rhyolitic material. This gave a high discoloring of the stain due to the high amount of ash content suspended in the water. Now the old rhyolitic mush is cleared out from the system, and the volcano is emitting predominantly unevolved basalt of deep origin.

This last part explains the low harmonic tremor since basalts travel easily in the conduits compared to the semi-solid rhyolitic mush, especially in a well worn feeder tube like the one leading to Bob. Another thing is that rhyolites are famously explosive and creates a lot of noise when erupting.

As I have now said time and again. Bob is not a volcano. The volcano is Tanganasoga, with the feeder system leading to Bob functioning as a pressure relief valve at the far end of the fissure swarm leading south from Tanganasoga. During the eruption there have been long periods of very low tremor associated with possible deep magmatic movement. This low frequency tremor is most easy to spot at the stations named EOSO and EGOM, and are found as clear red lines at the 0.59Hz and the 0.3Hz bands.

This gives that as the pressure has gotten into equilibrium the noisiness falls even more. Bob is now ejecting magma at the same rate as it is introduced into the system by the hotspot. With this in mind we can rule out any large changes in the eruption as long as the vents are open. And the eruption can be a very long one.

Thanks to the regular commentators Judith and CarlosB for digging out the newly released reports in a very quick fashion.

http://www.ieo.es/apartar/ieoprensa/hierro/hierro_leg11.pdf

http://www.ieo.es/apartar/ieoprensa/hierro/hierro_leg12.pdf

CARL

Sheepy Dalek – Ramon Margalef Day!

We have been nagging the Powers that be a lot for more information. Now that have gotten a lot of information I would like to thank the brave crew of S/Y Ramon Margalef and the IEO for it, by dedicating tonights Sheepy Dalek to them.

Our heartfelt thanks to you girls and guys!

I hope it did not feel like this while you did your work.

CARL

El Hierro – Short Update (Updated)

MAJOR UPDATE DUE TO IEO REPORT!

Image by IEO and scientist of S/Y Ramon Margalef, IGN and Gobierno de Canaries. If anyone feel left out in the ascertation of who is reponsible for this nice picture, just tell us.

IEO has released a report on the bathymetric measurments. It is based on the measurments from 11th and 12th of January. So it does not take into account the last weeks heightened activity.

The current depth of the volcano is 130 meters. The cone is now mended with new material and has a lower incline of the slope, and should as such be more stable. This new stabillity should give Bob a good chance at growing if the eruption continues.

A lot of the ejected material has gone down slope, both from the earlier flank collaps, but also with a lot of new material. It has now filled up the canyon leading away from Bob. This should also increase the growth rate.

The total volume ejected via the volcanic flank eruption vent called Bob is now above the 0,145 cubic kilometre mark. Considering the amount of tephra suspended in the water, high volume of floating pumice stone (pyroclasts) we could now consider Bob to be rated at a VEI-3 on the explosivity scale. But remember that this has been achieved over more than a hundred days of activity. As a direct comparison we can compare with Eyjafjallajökulls eruption that lasted about 90 days and ejected a total lava volume of 1.4 ± 0.1 x 10⁷ m³, comparing tephra volume is hard, but should be about the same really although the tephra here is suspended in the water. But judging from stain size it is a probable guess that we can assume roughly that Bob has ejected 1.4 x 10⁸ m³ of tephra.

Our little Bob is actually not that small. Just very slow and steady in his build up.

 Post from before:

Image by IGN showing clear clipping of the signal. Later the signal was rescaled due to this clipping.

Between 11.00 and 12.53 the SIL-station at CHIE showed a very large increase in harmonic tremoring causin the signal to overload and clip. The pattern showed every sign of a full blown eruption happening down there. There have been reports of prolonged steaming from the same spot, and a lot of gas has been spotted coming up. I have also seen pyroclasts surfacing during the day.

This clipping forced a rescale of the plot to be able to follow what is happening. Compare with EGOM station and the rescale is obvious.

During the last two days the temperature above the vent has increased in temperature.

This level of activity has not been since back when the eruption was at its previous peak. There has as the readers of this blog knows been quite a lot of activity at the volcanic vent known as Bob, as well as rapid movements indicating a succession of inflation and deflation periods happening under the Tanganasoga volcano.

Image by GeoLurking (Lurking). Slight decrease in distances between GPS stations on El Hierro following a phase of rapid expansion between them. Based on data from IGN.

The next few days might be very interesting for those who like to follow Bob south of La Restinga.

Wanted

GeoLurking (Lurking) has during the last days asked for thermal imaging, or satellite thermal images. If anyone knows where to find them, or have access to them, please inform him in a comment in here. We will all benefit from this in the usual plotted manner I am sure.

CARL