El Hierro

[jand]

Posted on jonfr.com/volcano in answer to a question about the possibilty of a  Tsunami.


Its universally accepted that the threshold most of the time for these is about 6.5. The sea floor has to subside, rise or in the case of a megathrust such as Chile or Indonesia, snap from being impinged on another plate back into place. Not going to get that from a 4.4 mag quake. Might see a couple of inches on the beach if its close and it has all those characteristics.

In addition, its the type of quake that caused it. Magmatic quakes rarely (I cant remember any) get beyond 4.5 unless its D-day in the eruption and then just about anything can happen, but most of the time that happening is above the local surface and causes the volcano to explode and even then there are other things that happen to cause it.

Tsunami threat-I refer you back to the papers about the overburden of the flanks of the old volcanoes on the island. The mountains are almost sheer and they have been undercut in inverted "U" and "C" formations. The estimated force to pop them loose is in the 5.5 range and maybe not even then. It has happened before and carried 1 km blocks out to 35 kms with the total distance on the La Calmas side being out to about 135 kms. Thats the biggest threat out there for tsunami right now. Later as this thing manifests itself something might happen like the fissure opening from Restinga out to El Golfo but thats a long hard reach too. I suggested that but just got in and started reading as I posed it to Erik K and Boris B. Have to see if they answered yet.

If you are on the island my suggestion is that you leave. You can be sitting on another island watching all of this on local TV and sucking on a fudgesicle all the while being safe in doing so.

[tamara_k]

jand

what you mean is not so much a "tsunami alert", but rather a tsunami warning system - http://en.wikipedia.org/wiki/Tsunami_warning_system . Those are usually installed in the areas where there's high risk of it occurring - for example, along the ring of fire http://en.wikipedia.org/wiki/Pacific_Ring_of_Fire. It's not a bad idea to have a universal public alert system in place anyway, although for all I know there might be one here, I am just not aware of it. However, you simply can't install sirens, signs for high ground etc along all the coasts of what is essentially one big nature reserve, so the example with "on a beach somewhere" doesn't work.

And before you say "why can't you" - just imagine you try to install something like that in Cornwall. After all, there is a risk, it did happen in the past http://en.wikipedia.org/wiki/Tsunamis_affecting_the_British_Isles (wow, there was one in June this year. 40 cm high one)

can you please post the full links you refer to. If you work in windows, mark  all the contents of the url or the page (including www , http etc), press Ctrl-C to copy, and paste it into your message by pressing ctrl-v

[jand]

www.jonfr.com/volcano

The latest update and blogs on this site are very interesting.

Especially as info was coming through quicker because one of the pilots on the helicopter was the sister of someone who was updating on this site and she has put some info on this morning that she hopes she wont be sent to prison for!!!

Tamara thanks for the helpful hints is this also how I attach photos aswell.

Yes you are correct I do mean a Tusanmi pre advanced warning system

[jand]

www.earthquake-report.com


Update 05/11 – 11:15 UTC :
 3 rather strong earthquake respectively 3.0, 3.5 and 3.9 have struck the El Golfo area to the North West of Frontera. The focal depths were in between 20 and 21 km (as most of the others before).
 The big difference with prior periods is that we now are having AND continuing strong earthquakes AND also INCREASED STRONG harmonic tremor. The rescaled IGN graph (yesterday evening) is almost saturated again. All this means very strong volcanic action below El Hierro.

[kevin2003]

quote:Originally posted by jand


This subject is being talked about all over the internet and all over the world.

[tamara_k]

jand

To add a picture, put the pointer over it, click with the _right_ button of the mouse (usually you work with  the left one). A dialog will pop up. Choose "Copy Image Location" from the dialog. Now, it the forum window, click on "Insert picture" button in "Format" butting row above the message field. It will insert a pair of html formatting tags into your message. Ctrl-v (insert) the location of the image which you just copied between the tags.

Hope it helps

[TripleH]

Jand, when do you go on your holidays?

[Magoo]

quote:Originally posted by jand

Magoo

I really am trying to be practical here and do not wish to scaremonger at all.

I am not saying that the canarian goverment should start an island panic what I am saying surely under the circumstances at least they should put some form of alert maybe sirens on each island to warn people IF the earthquake tremors start a wave that could turn into a Tsunmi.

An interesting thought Jand, but not as simple as you might think. To work, a tsunami warning system needs two things, detection equipment (buoys) & more importantly, time.  As Tamara points out, it is unlikely the kit is in place to detect an approaching tsunami. Also, using a back of a cigarette packet calculation, I recon that you are looking at about 30min, between the s**t hitting the fan at El Hierro, & surf up in El Cotillo (less in Jandia)
That's pushing it even for a fully automated system. A manual one that has to go through several layers of procrastination, has no chance.

Unfortunately,  apart from giving out information, you are stuck  with precautions such as  moving all civil defence up hill, stocking up on emergency supplies & thinking about getting a garrison in from the mainland upfront, as all ports & Fuerty's very low lying airport are going to be out of action after the event.

To be honest, unless the scientists get a lot more pessimistic, none of this will happen

[fifi]

Images released today of one of the eruption areas. (La Restinga)

[jand]

Now a 3.2 in the English Channel.

ML 3.2



Region

ENGLISH CHANNEL



Date time

2011-11-05 10:27:23.5 UTC



Location

50.28 N ; 0.92 E



Depth

2 km



Distances

72 km SE Eastbourne (pop 112,906 ; local time 10:27:23.5 2011-11-05)
41 km NW Dieppe (pop 35,707 ; local time 11:27:23.5 2011-11-05)
39 km NW Berneval-le-grand (pop 1,089 ; local time 11:27:23.5 2011-11-05)





Source parameters provided by another agency

[kevin2003]

quote:Originally posted by jand

Now a 3.2 in the English Channel.

[jand]

foxnews.com

Spain Evacuates Homes in El Hierro Island Due to Volcanic Activity



Published November 05, 2011


MADRID-- The regional government of Spain's Canary Islands has ordered the evacuation of homes and road closures near the southern tip of El Hierro island after two earth tremors and increased offshore volcanic activity caused a buildup of bad-smelling debris floating on the sea.

Seismic activity began in the area on July 17 and residents have since been rocked by more than 10,000 tremors, while underwater fissures have released an almost continuous flow of sulfurous gases, smoke and hot objects.

The government said in a statement it has evacuated 11 homes and closed the island's main road tunnel after a tremor of 3.9 magnitude on Saturday followed one of 4.4 magnitude the previous evening.

El Hierro has some 11,000 residents and was formed by volcanic activity.


Read more: http://www.foxnews.com/world/2011/11/05/spain-evacuates-homes-in-el-hierro-island-due-to-volcanic-activity/#ixzz1cqCZol00

[Florence]

quote:Originally posted by jand

Maybe I am missing something here over 13000 views on this BORING thread!!!

To be fair - most of those views are from you - and most of the cut and paste dross, not to mention the obsessive siesmic IGN watching.  Why comment on these when you don't even understand the difference between volcanic hotspot siesmic activity and tectonic plate movement?

[jand]

Update 05/11 – 16:35 UTC :
 IGN announced that they expect a new vent to open or already opened in the El Golfo bay, but at a far bigger depth than at the La Restinga coast. The main  eruptive vent is still located to the south in the Las Calmas sea. (ER : let's hope that the poor images of the NASA satellites will help us out in detecting an eventual coloring of the water).
 IGN also said that last night 4.4 magnitude earthquake was perceived much stronger by the population because of the  close distance to the beach. The earlier big quake was weakened by the water masses.

[jand]

Update 05/11 – 16:51 UTC :
 Presidencia del Gobierno de Canarias has published 2 new images taken with the helicopter who was seen by Joke this morning. They are still showing a strong emitting vent in the Las Calmas sea. If the eruption in this vent is magmatic, than the depth must have been seriously decreased since the eruption began. It is hard however to know this,  as the authorities are NOT disclosing the geographic positions of the vents.

[jand]

Update 05/11 – 18:10 UTC :
 We just got a call from an excited Joke Volta that a new powerful Jacuzzi (vent) can be seen from the La Restinga El Pinar road. She is curently making pictures from it.

[fifi]

http://www.gobcan.es/noticias/index.jsp?module=1&page=nota.htm&id=144488

Access to the tunnell  from both directions closed to traffic apart from  Security and Emergency services. Some other roads closed also. There is no more risk than ever to the Population according to the General manager of the Scientific committee.

[jand]

Florence

Oh by the way there are 14156 views now and only 621 postings and since your ludicrous statement I have not posted or viewed 1156 times.

Also as I am not the only the person posting on here you seem to be a bit way out with your statement .

Only 4% of the postings are part of the 14156 views and I am only one part of the 4%.

The remaining 96% of the 14156 are people viewing not posting.

This is also the last time I am going to respond to any of your future postings .

[jand]

VERY IMPORTANT Update 05/11 – 18:36 UTC :
 We do not like to call it "Breaking news" in the title, but we just received a confirmation from Raymond Matabosch that he sees at this moment at least 5 Jacuzzi's getting stronger.
Some jacuzzi's are taking the effect of low geyser activity.
 Raymond can see this at this moment from his location somewhere on the coast.
 Original text Raymond : mais il y a plusieurs jacuzzi (j'en ai compté 5) en face de Puerto Naos et La Restinga et de plus en plus puissants... certains forment même des geysers que je vois depuis la Montagne El Julan...

[fifi]

Late this evening, just before sunset,  the submarine eruption has intensified .- The bubble looms on the surface .- The Security and Emergency Councillor of the City of El Pinar has confirmed the decision to move to the population
The risk has not changed over days for the population, as recently reported following the meeting of this Saturdays PEVOLCA( Canarias7 translated.)





Typical....it has to move on a stage on a night when I have to go out. I will look for some more photos when I get back. []

[kevin2003]

quote:Originally posted by fifi

[fifi]

[][][]

[jand]

IMMEDIATE EVACUATION CALLED AT LA RESTINGA ('source : Diario El Hierro) due to the stronger coastal activity and toxic gases

VERY IMPORTANT Update 05/11 – 18:36 UTC :
 We do not like to call it "Breaking news" in the title, but we just received a confirmation from Raymond Matabosch that he sees at this moment at least 5 Jacuzzi's

[jand]

Lets all hope they have not left this to late !!!!

[jand]

Its live on canarian Tv now TV Canaria

[jand]

People are being taken out of their houses in their pyjamas looks like it was just the older people.

[kevin2003]

quote:Originally posted by jand

Lets all hope they have not left this to late !!!!

[fifi]

Watching the reports on tv here, no close up shots so far.http://www.rtvc.es/inicio/home.aspx

[fifi]

Some of the people in La Palma went up the mountain on camels to have a look at it.[]

[kevin2003]

quote:Originally posted by fifi

Some of the people in La Palma went up the mountain on camels to have a look at it.[]

What? No petrol for the cars in La Palma! We're doomed I tell ya! Doomed![]