Earthquake Swarm (11000+) El Hierro, Canary Islands

maquiladora

Holy crap, just saw the seismogram.

Thats either some serious interference or a volcanic tremor has started and magma is really on the move now.

Possible eruption in hours/days. Will be interesting to see if it will be at sea or on land.

maquiladora

141_Oscar_Mike wrote: »

Just had a look on ign. I see more shallow quakes than usuall alright but no tremors recorded on 10/10/11. What am i missing?

What appears to be a volcanic tremor appears to have started a few hours ago:

http://www.02.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-10&estacion=CHIE&Anio=2011&Mes=07&Dia=23

maquiladora

IGN will release a statement at 12:00 and seem to have confirmed to local media that changes are indeed happening, so its not noise or anything artificial.

It seems that diving around El Hierro has been prohibited now.

Edit : Looking increasingly likely the eruption could be out at sea. There won't be much for us to see if that is the case!

cherryghost

Nice rainbow.



The area south is actually quite shallow so we may see something yet.

maquiladora

Local media saying that ships have been alerted to possible volcanic activity 4km off the coast and that helicopters are over the area trying to see if there are any visible clues on the surface.

cherryghost

Any webcams of any sort hovering around?

cherryghost

From a local news website, translated:

El Hierro fears an increase in activity which remains in yellow light

The earthquake on Saturday, the greatest yet recorded, it was widely felt in La Restinga, El Pinar, Valverde, Echedo, Frontera, El Mocanal, Sabina, Timimiraque, or The Tamaduste.
Many people in El Hierro wonder what would happen if the light turns red.
Disminuye letra Aumenta letra





DIARIOELHIERRO.ES, redacción (10/10/2011. 08:00 horas) DIARIOELHIERRO.ES, writing (10.10.2011. 08:00 am)

The inhabitants of the island of El Hierro are increasingly anxious and fearful. The earthquake of 4.3 magnitude (which is now cut to 4.0 IGN magnitude on the Richter scale after several modifications and intensity IV on the scale EMS 98), was widely felt in La Restinga, El Pinar, Valverde, Echedo , Frontera, El Mocanal, Sabina, Timimiraque, or The Tamaduste. . Some of these towns was the first time they felt a tremor.

Many people in La Restinga and El Pinar, to name the towns where recent seismic activity is concentrated to bed every night with uncertainty and fears of a major shock. "Many of us have trouble sleeping, my children wake up scared every time I feel the bed move them," she told a neighbor DAILY IRON La Restinga who prefers to remain anonymous. The day's major quake (Saturday at 21:37 hours) many of these people left their homes due to the strong movement. "It's horrible to see how you move your house, your pictures, and feel the ground tremble beneath your feet," adds this neighbor.

Thus he lives the onslaught of El Hierro magma, sometimes only one kilometer from the coast and others seem to back away. IGN continues to record, however, depths of more than 10 kilometers, but on Sunday (as listed on their website) will detect earthquakes of 1.5 and 1.7 magnitude on the Richter scale, just 3, 2 and 1 km, between 1.5 and 1.7 degrees although, from the Canary Islands Government insists that they are provisional data, but 24 hours are posted on the website of the Institute has no one to date. Con todo, se debe esperar a que IGN los actualice. However, it must wait for the update IGN.

For example, this this Monday, October 10, the National Geographic Institute (IGN) has not recorded any earthquake on the island of El Hierro. The last one shows the IGN website is the place on Sunday at 22:42 hours canaria, of 1.5 magnitude on the Richter scale and 15 kilometers deep.

Meanwhile, the Canary Islands Government insists on calling the El Hierro population calm and remember that we are in a state of yellow light so that the succession of felt earthquakes fall within the normal range and there is an impending volcanic eruption.

For its part, the Minister of Safety and Emergency Cabildo de El Hierro, Maria del Carmen Morales, had already warned that, indeed, earthquakes of magnitude could increase "to 4 or 4.5 degrees", as it has happened.

WHAT IF the light turns red?

As with traffic lights, the light volcanic consists of three levels: green, normal, yellow, listen to those reported by the authorities, and red, made available to the authorities to evacuate or take action deemed appropriate.

For example, in the case of the island of El Hierro, the yellow light should be applied to the entire island, however, the red would only affect the area near the place where it can cause a rash, says the association "Volcanoes Canaries ".

Volcanic light management for the population lies in the direction of Pevolca. It decides the most appropriate color based on data that are provided or according to their own criteria.

Indeed, this Monday, October 10, meets Valvefrde Pevolca in a meeting that has nothing to do with the earthquake occurred on Saturday, as was predicted before it happened.

Sources consulted by DAILY IRON estimate that the light will stay yellow, and that this meeting will discuss mainly the situation in Los Roquille tunnel, vital to Valley communities of the Gulf with the rest of the island.

maquiladora

Through translation:

Seismic monitoring services have seen a small eruption at 1,200 meters deep in the ocean and 7 miles from El Hierro. The phenomenon has occurred at 10.43 (local time) and there has been a sudden change in the seismic process...

http://www.elmundo.es/elmundo/2011/10/10/espana/1318242424.html

Hopefully some clearer information at 12:00. Every report I see has different figures for depths and distances from land.

maquiladora

From Jon Frimann's blog :

Jón Frímann says:
October 10, 2011 at 10:37

This is a harmonic tremor that is appearing on El Hierro tremor plot. From what I can tell this is a growing eruption. But that suggests a fissure eruption that is currently expanding. The eruptions appears to have started around 04:20 UTC.

This is almost the same thing as did happen in Eyjafjallajökull volcano, when the fissure did open up there. It was a quiet start to a volcano eruption, as we all remember.

maquiladora

Still no official statement/press release. Local media are "confirming" an eruption at sea but the details are different in each report.

Locations of the most recent earthquakes:

cherryghost

There's live coverage of the activity on Canaries TV

EDIT: Coverage is over already

vibe666

reported here: http://www.canariesnews.com/2011/10/10/possible-volcanic-eruption-off-coast-of-el-hierro/

maquiladora

David Calvo tweets :

NO confirmation about the eruption, only based on tremor signals. Media "tremors" spreading chaos....

Edit: The latest from IGN is that a "thermal and visual inspection" from a helicopter has shown no evidence of an undersea eruption.

je55ie

http://www.irishweatheronline.com/news/earth-science/geology/subsea-volcanic-eruption-underway-near-el-hierro-the-canary-islands/41266.html

A submarine volcanic eruption is taking place approximately 5 kilometres off the southern coast of El Hierro, the smallest of The Canary Islands.

"The Mayor of La Frontera (El Hierro), David Cabrera, confirmed in an interview on Radio iron Garoé that ‘underwater eruption’ is taking place about 900 metres beneath the sea surface five kilometres south of La Restinga. The eruption has been ongoing for four hours, the Mayor said."

je55ie

Enrique from Actualidad Volcanica de Canarias:


"I think, and it is my personal opinion that what is south of the Restinga in the sea ... several hundred meters is a gas vent, I'm missing things. I think that the eruption is yet to come and I need seismicity. The next 48 hours will be key. At the moment we waiting for that statement .."

cherryghost

141_Oscar_Mike wrote: »

Why cant we see the tremors we were seeing over the past weeks? Whats goin on there?

What do you mean? The history of the quakes is working just fine on the website

cherryghost

Jón Frímann says:
October 10, 2011 at 12:52
From what I can gather on the tremor. It seems that this eruption is growing in size every 2 hours or so.

Its hard to see but it has indeed been gathering energy ever slow slightly in the last few hours



Maybe a better way to read into is the observation that the white gaps between hourly periods have nearly disappeared.

Weylin

October 9, 2011 – CANARY ISLANDS – A 4.3 magnitude earthquake struck El Hierro, the smallest of The Canary Islands, late on Saturday night. It was the strongest earthquake to be recorded on the Spanish island since an unprecedented earthquake swarm commenced during the summer. The Instituto Geografico Nacional (IGN) has reported an increase in the intensity of earthquakes recorded on El Hierro, the smallest of The Canary Islands, during the last 48 hours. The number of earthquakes recorded since July 17 , 2011 on El Hierros has now reached 10,000, figures from the IGN confirm. The IGN also confirmed surface deformations exceeding 35mm on the 280-sqkm island, where residents have been put on alert for a possible volcanic eruption. However, seismologists have moved to reassure the local population that a volcanic eruption is not imminent. The agency confirmed on Friday that 886 earthquakes, most of them located in the sea to the SW of the island, have been recorded in the 7 days since 02 October, 2011. During this period, 71 earthquakes were felt by the island’s estimated 10,000 residents. Since Friday morning, there have been more than two dozen earthquakes exceeding 3.0 on the Richter Scale with epicenters both North and South of the NW Ridge and depths between 10 and 15 km have been recorded. The strongest of the tremors measured 4.3 magnitude on the Richter Scale, many times stronger than other earthquakes recorded on the island since mid-July. It was recorded on Saturday night at a depth of 12 km. The quake produced small rockslides but no injuries were reported. -IWO

je55ie

http://www.emergenciaselhierro.org/

"The address PEVOLCA says there is no certainty of an underwater volcanic eruption on the island of El Hierro
• IGN gained during the last morning a small release of fluids and volcanic gases that do not pose such risk to the population"


Google translated

maquiladora

141_Oscar_Mike wrote: »

cherryghost wrote: »

What do you mean? The history of the quakes is working just fine on the website

Is it? Im just seeing 4 tremors for today here


http://www.01.ign.es/ign/layoutIn/sismoListadoTerremotos.do?zona=1&cantidad_dias=10

Those are individual earthquakes. The volcanic tremor has been ongoing constantly since early morning and is drowning out most earthquakes from being detected.

Weylin

Subsea Volcanic Eruption Underway Near El Hierro (The Canary Islands)

By Mark Dunphy - Mon Oct 10, 1:36 pm

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Edited byMark Dunphy

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El Hierro, The Canary Islands, from space in this MODIS satellite image on Oct. 7 2011



A submarine volcanic eruption is taking place approximately 5 kilometres off the southern coast of El Hierro, the smallest of The Canary Islands.
The Mayor of La Frontera (El Hierro), David Cabrera, confirmed in an interview on Radio iron Garoé that ‘underwater eruption’ is taking place about 900 metres beneath the sea surface five kilometres south of La Restinga. The eruption has been ongoing for four hours, the Mayor said.
Spanish newspaper laopionion.es quoted the Minister of emergencies of the Cabildo of El Hierro, Maria of Carmen Morales, as saying the eruption is taking place because ‘the seismic movement of 4.3 occurred on Saturday afternoon caused a fissure, from where the energy is been released’. Scientists remain unclear if the emissions are gas or lava.
A meeting of PEVOLCA – Actualidad Volcánica de Canarias, comprising representatives of Instituto Geografico Nacional (IGN) and The Canary Islands Government, is presently taking place on the Spanish Island.
Meanwhile, La Agencia Estatal (CSIC) scientists equipped with special detection cameras have been making numerous sorties over coastal areas of El Hierro in an attempt to verify the existence and scale of the underwater eruption. This is Spain’s first volcanic eruption since 1971 when the erupted of the Teneguía volcano on the island of La Palma (Canary Islands), located to the north of El Hierro.
Initial reports of the eruption were received from crews on board four separate ships. On Monday afternoon, Terra Noticias/Agencia EFE reported that an eruption occurred 2000 metres below sea level in the Las Calmas sea at 10.43 local time (05:43 EDT). Spanish newspaper El Mundo placed the depth of the eruption at 13oo metres.
Local media agency Canarias7 reported on Monday that Government authorities have suspended ferry activities to and from the 285 square-kilometre island. English language newspaper islandconnections.eu reported: “The martime chief for the province of Santa Cruz de Tenerife Antonio Padrón has issued a recomendation that boats should not sail closer than four miles off El Hierro. Divers have also been told to suspend all activities.”

Background To The Eruption

El Hierro (highlighted) on Google Earth

The eruption takes place amidst an unprecedented earthquake swarm in El Hierro. The number of earthquakes recorded since July 17, 2011 on El Hierro has now exceeded 10,000.
Hierro, a shield volcano, has had a single historic eruption from the Volcan de Lomo Negro vent in 1793. The eruption lasted approximately one month and produced lava flows.
The recent surge in the number and intensity of earthquakes prompted officials from the IGN and The Canary Islands Government to raise the alert level for the Hierro volcano to ‘Yellow’ late last month. The alert remained in place on Monday, but the estimated 11,000 residents of El Hierro were being reassured not to be alarmed.
The majority of the earthquake activity shifted from El Golfo in the island’s northwest to beneath the Las Calmas Sea in the south earlier this month. Surface deformations exceeding 35mm have also been recorded on the island in recent weeks.
Evacuations

A dramatic rise in recorded earthquakes on El Hierro prompted officials to evacuate some local residents, shut El Hierro’s main tunnel, and close local schools on 27 September.
The Spanish Civil Guard (Guardia Civil) advised almost 50 residents of the municipality of La Frontera to leave their homes because of landslide fears. Two units of the Spanish military’s emergency intervention unit (EMU) were also placed on standby to depart the nearby island of Tenerife to assist in the possible evacuation of hundreds of other El Hierro residents.
Meanwhile, the island’s main tunnel (Tunel del Golfo), which links Frontera to Valverde, was shut forcing motorists to travel across the 280-sq-km island via a mountain road. The Cabildo de El Hierro also ordered the closure of schools.
Latest seismic activity on El Hierro



IGN graphic of recent earthquakes (marked in red) on El Hierro



Possible Harmonic Tremor On El Hierro

Earthquake Swarms

Earthquake swarms are events where a local area experiences sequences of many earthquakes striking in a relatively short period of time. The length of time used to define the swarm itself varies, but the United States Geological Survey (USGS) points out that an event may last for days, weeks, or months.
Harmonic Tremors

Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral (harmonic) lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor is a sustained signal that may or may not possess these harmonic spectral features.
El Hierro’s Volcanic/Seismic Past

El Hierro is situated in the most southwestern extreme of the Canaries. The island was formed after three successive eruptions, and consequent accumulations, the island emerged from the ocean as an imposing triangular pyramid crowned by a volcano more than 2,000 metres high.
The volcanic activity, principally at the convergence of the three ridges, resulted in the continual expansion of the island. A mere 50,000 years ago, as a result of seismic tremors which produced massive landslides, a giant piece of the island cracked off, crashed down into the ocean and scattered along the seabed. This landslide of more than 300km3 gave rise to the impressive amphitheatre of the El Golfo valley and at the same time caused a tsunami that most likely rose over 100 metres high and probably reached as far as the American coast.
El Golfo, El Hierro, The Canary Islands (Spain) where the majority of earthquakes have been recorded up to recently

According to the Global Volcanism Program, the massive Hierro shield volcano is truncated by a large NW-facing escarpment, seen here from the east, which formed as a result of gravitational collapse of the volcano. The steep-sided 1500-m-high scarp towers above a low lava platform bordering 12-km-wide El Golfo Bay, which is barely visible at the extreme left. Holocene cones and flows are found both on the outer flanks and in the El Golfo depression. The last eruption, during the 18th century, produced a lava flow from a cinder cone on the NW side of El Golfo.
According to ElHierro.com: “Although over 200 years have elapsed since the last eruption, El Hierro has the largest number of volcanoes in the Canaries with over 500 open sky cones, another 300 covered by the most recent outflows, and some 70 caves and volcanic galleries, notably the Don Justo cave whose collection of channels surpasses 6km in length.”
El Hierro is located south of Isla de la Palma (population 86,000), currently the most volcanically active of the Canary Islands. About a half a million years ago, the volcano, Taburiente, collapsed with a giant landslide, forming the Caldera de Taburiente. Since the Spanish occupation, there have been seven eruptions.

maquiladora

Tweets from David Calvo this evening

@eruptionsblog IGN denies detecting any gas or magma release, as said by the authorities. This is unreal....man.
4 hours ago via web

@pabloj_gonzalez @eruptionsblog maybe some unexperienced personnel saw tremor and said "eruption"...it looks like a game, yes, no, maybe...
4 hours ago via web

@pabloj_gonzalez @eruptionsblog and i do believe so, there´s a new situation for them, tremor is more complex than anyone may think.

And a roughly translated statement from the non official AVCAN group. (IGN is the official body, like the USGS of Spain)

Total confusion. Thus we can summarize the course of the morning Monday, October 10. Although I still I have not heard from where it departed on the news (I have been working until a few minutes ago), have spent all day talking about an alleged eruption at sea. After contact with the headquarters of the Coordination Center for security and emergencies, in Tenerife and Gran Canaria, the first information that I give is unanimous: "there is nothing to report." The Pevolca is met. "." Do not confirm me any of the rumors that I have received, on prohibition of go out fishing, scuba diving, etc.

They take my data, and knowing that I call representing AVCAN, say me if they have information to call me to inform me. At this time, they have not done yet, but I understand that they have other things more priority. Later, the end of the meeting of the Pevolca, and press conference. In short: "No we cannot confirm eruption." But at the same time, other two participants at the same meeting, the Mayor and the President of the Cabildo of El Hierro, emerging media by claiming that the eruption is in the sea, a few kilometers south of La Restinga.

In this situation, once again, contact centre Coordinator of security and emergencies. I serves the same lady, and very kind, explains to me that they are in LA MISMA situation of CONFUSION. Counter news arrive to them from various sources, and they themselves do not know who adhere. It seems very serious to me that you have reached this situation of lack of control.

To complicate matters, the lack of some important media (for example, a seismic array or a scientific ship) more difficult things at crucial moments. So much so, we have been "blind" to the seismicity of moderate magnitude, covered by the noise produced by the tremor.

Now, IGN seems to backtrack everything, there is no eruption, only a movement of gases or fluids. If there was no guarantee, is why it gave alarm?

In summary, it seems to my that eventually the eruption has not begun yet, as the signal that us has brought head is a volcanic tremor, and that the work administrations being blameless so far, it has been tainted by a lousy management of information, the publication of a eruption when it was not known whether it existed or not, and because the latter evidence instruments deployed in El Hierro, being large, it is not enough.

cherryghost

There's almost 1.4 TRILLION Joules of energy going on down there at the moment, with no sign of a release apparently. Tremors are still increasing, starting to go off the charts :P

maquiladora

From Jon Frimann, about an hour ago.

This is most interesting case. But what seems to be going on, from what I can tell. Is that magma is rising up the surface. A eruption does not seems to have started yet. At least it cannot be found for sure. It might well be that the magma is travelling old magma conduct that was empty (caves?), that might explain the lack of earthquakes.

Given the current increase in tremor and possible depth, I would expect first signs of the eruption to be in 3 to 6 hour time. But it might be longer however, as this landscape in the ground might change the speed of the magma.

Rikand

cherryghost wrote: »

There's almost 1.4 TRILLION Joules of energy going on down there at the moment,

is there any way we could tap that ?

maquiladora

New tweet from David Calvo :

reports about batches of dead fish appearing in Southern El Hierro. Waiting for confirmation. Tremor still strong

This spectrogram chart shows the increasing tremor from early this morning until now.

maquiladora

David Calvo/local TV there now saying that IGN are confirming that an eruption has happened at sea. Gas measurements, ground deflation and dead fish cited as evidence.

kindredspirit

Talking about bits of the Canaries vanishing into the sea, here's a video of land vanishing into the sea, a bit nearer. Normal coastal erosion though, not volcanic movement.

http://uk.news.yahoo.com/dramatic-footage-of-cornwall-cliff-collapse-emerges.html

Longboard

maquiladora

The harmonic tremor has started to go "off the scale" since about 7am this morning. You can see at the top of the spectrogram, the blue has turned into more of a solid block over the last couple of hours, indicating that the peaks are higher than what can actually be depicted.