[aktueel] Vulkaanuitbarsting bij Canarische Eilanden #3

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Recordaantal aardbevingen op Canarisch eiland

Nog nooit eerder werden er zoveel aardbevingen achter elkaar geregistreerd op het kleine vulkanische eilandje El Hierro, het kleinste van de Canarische Eilanden. De reeks van maar liefst 720 bevinkjes heeft de overheid van deze eilandengroep voor de kust van West Afrika ertoe doen besluiten om voor het eerst in de geschiedenis een vergadering bijeen te roepen van het Stuurcomit� van Vulkanische Monitoring. Dit comit� werd opgericht om specifieke plannen te realiseren, die de burgerbevolking dienen te beschermen en noodplannen voor vulkanische risico’s moeten ontwikkelen. Inmiddels wordt gesproken over een ‘significante dreiging van seismische activiteit’.

Het Nationaal Geografisch Instituut (IGN) en het Volcanologische Instituut van de Canarische eilanden blijft nauwlettend de aardbevingen in de gaten houden, waarvan de kracht van de bevingen (elke dag!) ligt tussen de 1 en 3 op de Richterschaal. De meerderheid van de bevingen vindt plaats tussen 5 en 15 km diepte.

Volgens de autoriteiten betekent deze seismische activiteit nog niet direct dat een grotere, significante aardbeving zal plaatsvinden. Het merendeel van de bevingen die zijn geregistreerd, vonden plaats in het Noord Westen van het 280 vierkante kilometer kleine eilandje, bij het plaatsje El Golfo (zie foto hieronder). Een aardbeving op deze plaats zorgde er zo’n 50.000 jaar geleden voor, dat er een enorme landverschuiving plaatsvond, waarbij de helft van de vulkaan in zee gleed. Hierdoor ontstond een ca. 100 meter hoge tsunami die naar de overzijde van de Atlantische oceaan zou zijn gegleden. Schuin tegenover dit eilandje, in het verlengde van de resterende halve kratermond, ligt het Noord Amerikaanse continent..

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El Hierro Earthquake Swarm Enters Third Week
The intensity of earthquakes recorded on the smallest of the Canary Islands, El Hierro, has increased slightly during the last 24 hours. However, the total number of earthquakes recorded daily has lessened since the earthquake swarm initially began on 17 July.

The total number of tremors recorded during the past two weeks has now exceeded 1,050, according to the Instituto Geografico Nacional (IGN).

The majority of the earth tremors ranged between 1-2 magnitude, but during the past 24 hours there have been least five tremors measuring in excess of 2.0 magnitude on the Richter Scale. A 2.4 magnitude earthquake was recorded at 4:56 p.m. local time on Sunday (31 July 2011).

Approximately 50 earth tremors were recorded on Sunday, according to local earthquake monitoring agency Actualidad Volc�nica de Canarias (AVCAN). The number is slightly down on the number of tremors recorded on Saturday and significantly less than the 195 earthquakes recorded on 22 July.

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The vast majority of the tremors have been recorded in the northwest of the 278.5-square-kilometre island at El Golfo, the location of a massive landslide that created a 100-metre high tsunami almost 50,000 years ago.

The earthquake swarm, prompted the Canary Islands Government to convene the first ever meeting on 22 July of the Steering Committee and Volcanic Monitoring, reflected in the Specific Plan Protection Civil and Emergency for Volcanic Risk, given what it described “the significant increase in seismic activity”. The Committee met again on Friday 29 July to discuss the low magnitude seismic activity. It reported that it had stepped up its seismic monitoring operations to identify the source of the earthquakes.

Following an evaluation of seismic and volcanological information gathered by the IGN and volcanological Institute of the Canary Islands, the Committee agreed to activate “monitoring and surveillance mechanisms necessary to coordinate the actions of civilian self-protection and information to people listed in the Plan” (translated from Spanish press release). It remains unclear, however, if the unprecedented seismic activitiy on El Hierro is a precursor to a possible future increase in earthquake or volcanic activity.

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.

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.

Nuevas imágenes de la mancha de emisiones volcánicas en la costa de El Hierro

Material piroclástico en superficie tras la erupción de El Hierro. Día 15-10-2011

Imágenes de la erupción el día 17-10-2011 donde se aprecia el foco principal de la misma

Underwater volcano errupting of coast Canary Islands emits toxic gases

Birth of a new vent on November 23

El volcán de La Restinga, El Hierro.

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NOTE AVCAN 343 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 25 November 2011-10:30 h peninsular - seismic-volcanic activity continues with moderate to high seismicity in the Gulf marine area. According to the PEVOLCA have appeared "quite often a type of volcanic signals (LP). Continued significant volcanic tremor signal in the Restinga area, which remains small amplitude oscillations, more unstable and more explosions, possibly hydromagmatic . the magnitude of the earthquakes between 3.1 and 1.5. New quakes 6. earthquakes senses 1. Depths one to 15, and the rest to 20km. the day before yesterday 21. Yesterday 8. Today van 4. A total of 11,807 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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The truth is that the photos of non-tip / Guardia Civil of the last day November 23, 2011 are beautiful, and one more thing to show us how small is the nucleus of the Restinga, at the foot of a volcanic cone aligned with other more behind and in line with the town, besides the spot next to the town, the thing is close, too much for my taste, so if the picture is very good, is a cover of National Georgraphic so far indicating eruption in el Hierro (Enrique).

Picture of intense volcanic gas discharge by submarine eruptive activity south of the Restinga on the morning of November 23, 2011. Photo: Civil Guard / InVolCan

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Todo se cuadra para la erupci�n en el norte

The great stain that is leaving the volcano on La Restinga overshadowed on Thursday what is happening in the north of El Hierro, where the location of small tremors in the seismicity and the increase in the rate of CO2 targets shallower magma movements.

The seismicity in the north of El Hierro is decreasing to the point that this Thursday there were only three earthquakes, however, and according to the committee of scientific work to the direction of the Civil Protection Plan for Volcanic Risk (Pevolca) have appeared "quite often a type of volcanic signals (lp) in the Stations of the North Coast." These signals volcanic long period (long period) are equivalent to small tremors associated interrupted movement of magma.

The director of the National Geographic Institute (IGN), Mar�a Jos� Blanco, rejected that means full already tremor signal in the north and, therefore, a rash, but admitted that the magma is moving appreciably off the coast . And it does more superficial positions if one looks at it this concatenation of small tremors is linked to a shallower seismicity in recent days in the north, between 15 and 18 kilometers deep.

Furthermore, these two elements adds an increased gas pressure in the magmatic thermal system. The last measurement of the diffuse emission of carbon dioxide (CO2) from the Canary Islands volcanological Institute (Pevolca) on day 20 is around 2,200 tonnes per day (400 tons more than four days before), a value equivalent to 6.34 times the normal average value on the island.

CO2 is the driving force of eruptions, which is why some experts have the feeling that they may be facing an eruptive phase in the north.

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Clouds and transit seismic hypocenters of seismicity to 11/24/2011

Nubes sísmicas de hipocentros y tránsito de la sismicidad al 24-11-2011

Clouds of seismic events and daily traffic of seismicity for seismic-volcanic crisis on the island of El Hierro to 24 November. of 2011

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The diffuse emission of carbon dioxide by the insular volcanic system is already six times the normal average

The diffuse flux measurements of carbon dioxide (CO2) since last July by scientists at the Institute of the Canary Islands volcanological (involcan) at El Hierro reflect an upward trend in their emission into the atmosphere by the volcano island, which is about the 2,200 tons per day. This is a value equivalent to 6.34 times the normal average for the island of El Hierro, which is 345 tons per day.

On the other hand, as reported in a statement, the stain caused by the underwater eruption off the coast of La Restinga has remained widespread in surface and appreciated "some sporadic changes in hue." The sending center has presented a brown color associated with the emission of fine material. On the tremor signal, its amplitude has remained constant and low throughout the day, with some slight increases and no evidence of any second source of tremor . Similarly, with respect to deformation, the results of processing the data obtained with the GPS stations do not reflect any clear trend in the horizontal components other than the regional. Vertically majority view stations and only a collapse of the Gulf seem to point to stability, mainly in the east. Also, the National Geographic Institute (IGN) confirmed the direction of the Civil Protection Plan for Volcanic Risk (Pevolca), that during this eight earthquakes were located Thursday, with only one of them felt by the population, with an intensity of II. Most of these events are located in the Gulf, aligned in the northeast-southwest in the sea at a depth between 15 and 24 kilometers. The more intense, with a magnitude of 2.8 on the Richter scale, had place at 20:54 hours west of La Frontera at a depth of 16 kilometers. In total, since the day July 17, 2011 11 832 earthquakes have been located.

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The evolution curve of the cumulative seismic energy released looks set moderating its rise, releasing less and less energy.

This may be because the system is relaxing or on the contrary it has been re-hitches and a few days ago, since it is still early to rely, as the last time you did this, ended with a 4.6, Will this in the coming days? or else I still relax, releasing less and less energy?

We'll see what happens, but seeing the gases and the deformation does not seem to be relaxed, especially gases (Enrique)
[bron]

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Update 26/11 – 12:42
The best you can do at the moment is staring at our webcam. For minutes in a row, we have seen periods of smoking magma. The smoking magma was first seen by reader Hans-Werner who also captured the image on his screen. Hans-Werner has told us also that the webcam was operated in the right direction when it happened. This is also great news to hear as the webcam operators seem to have learned from past critics.


Update 26/11 11:30
Joke reports that her friend, the La Restinga human webcam, has growing fear that a new evacuation is not far away as the stain is very visible from the village this morning (Ian reported the same in his 09:52 update). She thinks that if the wind eventually changes, La Restinga might be in the center of the storm again.
Update 26/11 11:28
- The volcanic earthquakes have picked up their daily work again. Since 09:21 this morning 4 M+1.5 earthquakes have been listed by IGN, the strongest one being a M 2.7 earthquake NW of Frontera
Update 26/11 09:52 Ian Carson reports :
A lot of stain right to coast at La Restinga but no emission points can be seen by me. I don't think the earlier mention of a closer one was true. Harmonic calm.
Update 26/11 09:43
- 3 earthquakes have occurred since midnight, all of them less than 1.5, the reason why these quakes are not listed in the IGN main list. 2 of these quakes had a depth of 14.8 km
- while looking at the webcam for a longer period a lot of mysteries are showing up. Here are a few of them :
- why can toppling waves almost only be spotted in the stain waters ?
- why do we have sudden color change in parts of the stain ?
Update 26/11 09:05
- the beautiful calm Las Calmas sea enables us this morning to trace the eruption vent. The arrow on the picture below is the location were we expect that the vent is (probably) degassing. About 15 to 30 minutes ago, we have spotted here the source of a white stain. Unfortunetely the Telefonica operators have since zoomed more to the left . The Telefonica operators have since zoomed the image and probable stirring action has to be located at the upper right corner.

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Data Update 26/11 – 23:42
- A lot of action in the sea means mostly a limited number of earthquakes. Today only 8.
- Depth in between 14.8 and 20.3 km
- Medium harmonic tremor with a limited number of bursts

Ian Carson reports from El Hierro :
I went to La Restinga at first light to see any overnight developments - there weren't any - just the usual stain a bit closer to the shore. After an hour and as it was lovely morning, I went sightseeing. I was returning to La Restigna when I got the message of smoking lava stones.
When I arrived there were little 'bombs coming to the surface intermittently. These got more frequent for a while and then only one every 5 mins. After a while the activity again increased, bright Jacuzzi and many stones coming up, generally smaller than the first batch. Stones were visible on the surface. The affected area seemed to be getting larger and the activity seemed quite intense when I had to leave at 17.40. I look forward to first light ! The Ian Carson images are included in the group below. Click on the image to watch the entire group of pictures.

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Data Update 27/11 – 09:14
The activity at the eruption area gets even stronger than before. The webcam operator just zoomed out a little to have a wider scoop. Earthquake-report.com expects more action today. A stronger Jacuzzi and from time to time a swelling geyser type action.

Data Update 27/11 – 08:50
The coast guard boat on the image will have the best pictures. What he does is however very risky as nobody can predict the start of a subaerial phase of the eruption.

Data Update 27/11 – 08:09
- the action which started yesterday by floating smoking stones is continuing this morning, hot pyroclastic material is floating to the surface. Just behind a weak Jacuzzi is formed. All this can be seen on the Telefonica eruption webcam.

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NOTE AVCAN 346 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 26 November 2011-21:30 h peninsular - seismic-volcanic activity continues with moderate to high seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, which is maintained in amplitude with increasing trend (10%) since the last note, with small oscillations and some explosions, possibly hydromagmatic (by the way the pattern has repeated explosions every 3 hours approx). The magnitude of the earthquakes between 2.2 and 1.5. New earthquakes 4. Depths to 17, 19, 19 and 20km. Before yesterday 8. Yesterday 10. Now go 8. A total of 11,821 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

NOTE AVCAN 347 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 27 November 2011-11:15 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, which is maintained in amplitude with the low tendency (5-10%) since the last note, with small oscillations, and more unstable, with some explosions, possibly hydromagmatic (indeed the pattern of repeated explosions every 3h approx). The magnitude of the earthquakes between 2.3 and 1.1. New earthquakes 11. 17 and 20km depth (and two at 2 and 14km and three to 21, 22 and 25km). The day before yesterday 10. Yesterday 9. Today are 10. A total of 11,832 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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Data Update 28/11 – 10:01 – Ian Carson reports
Just had long chat with scientists. Depth of vent yesterday was imprecise according to the captain. Now the real news, a new scientific ocean survey ship is coming tomorrow to map the area. It will also do work in the north (El Golfo region).

Data Update 28/11 08:33
- Harmonic tremor remained strong all night
- Contrary to yesterday, no smoking stones this morning. We have just watched a time lapsed period since the beginning of daylight and no surface activity has been noticed on the webcam
- Ian Carson reports that the usual stain is visible but no stirring activity
- 3 earthquakes since midnight, the strongest one being a M 2.0
- depths in between 17 and 21 km
- weather outlook for today : beautiful weather today, wind blowing from the east, maximum wave height : 0.6 meter, wind speed : 1 to 2 knots only in other words a perfect day for volcano activity spotting

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@eruptionsblog
New post! Taking a closer look at the mixing magmas erupting from El Hierro in the Canary Islands - a complicated mess: http://www.wired.com/wire(...)-el-hierro-eruption/

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NOTE AVCAN 350 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 28 November 2011-22:30 h peninsular - volcanic seismic activity continues to moderate-high, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude that has fallen and risen again (down to 30 and up to 15%) since the last note, and with small oscillations, and more unstable (drop to the 20:42 h), with some explosions, possibly hydromagmatic (by the way the pattern has been repeated every 3h explosion approx). The magnitude of the earthquakes between 2.9 and 1.1. New earthquakes 16. Depths between 19 and 21 km (and three to 13, 15 and 17km and another 23km. Before yesterday 9. Yesterday 16. Now go 20. A total of 11,858 earthquakes are located in El Hierro by IGN at 9:00 pm on 19 July 2011 (Enrique).
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I do not know how I will but I think we should agree on a name you can call, if only here, the volcano's so much talk. And if we do it democratically, which seems logical, the volcano located by the team of scientists from the Spanish Institute of Oceanography (IEO) in the South Rift of El Hierro, according to our survey, called Volcano calms. (Fernando)

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El Hierro Volcano Update : 28th November

Scientists from Spains National Geographical Institute (IGN) observing recent activity of the Canary Island of El Hierro have recorded a total of 10 earthquakes over the course of the last 24 Hours (13.00 Sunday - 13.00 Monday GMT).


As with recent days and weeks, the earthquakes were centered around the El Golfo bay area, to the Northwest of Frontera on the northern coast of the island. The recorded magnitudes varied from 1.5 to 2.2 on the richter scale and at depths between 17 - 21kms.


As with the southern coast of the island over recent weeks, an Oceanographic research vessel is due to arrive on the North of the Island to investigate and map the ocean floor in the El Golfo bay and to check for the likelihood of new volcanic vents being created.
Meanwhile, the Las Calmas bay area, off the coast of La Restinga on the south of the island have seen a development with the volcanic eruptions over the weekend. A new vent appears to have opened up 1.8 km from the coast and this has been accompanied with a marked change in the colour of the stain, together with the emission of sulfurous gasses and the production of a number of smouldering volcanic rocks being brought to the surface of the water.

Undersea Volcano Eruptions Caught On Video

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NOTE AVCAN 351 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 29 November 2011-11:45 h peninsular - seismic-volcanic activity continues to moderate-high, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude that has remained stable since the last note, and small oscillations and explosions, possibly hydromagmatic (by the way the pattern has repeated explosions every 2 hours approx). The magnitude of the earthquakes between 3.0 and 1.5. New quakes 7. Felt earthquakes 1. Depths to 16, 16, 17, 19, 20 and 23km. The day before yesterday 16. Yesterday 23. Today van 4. A total of 11,865 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).


For those who are curious as will the "Devil's staircase" or energy ladder or evolution of the cumulative seismic energy released from 4.6 until today, I leave you there, with the last steps of the earthquakes of yesterday and today at the end. By the way the patterns are 48h, and two at each 6h-12h also (Enrique)

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Decreased daily average depth, though, with only 4 events detected this day 29 half hour ago. The average weight is the result of energy released every event: Summary of the seismicity of day: 11/29/2011

Number of seismic events on the day: 4 at 11:10

Latitude weighted average energy released: 27,771

Average length weighted by energy released: 18,050

Depth-weighted average energy released: 15,416

Seismic energy released during the day: 10723049118099.76563 Joule

Equivalent Magnitude of the day: 3.0126

Average Energy per event day: 2680762279524.941407500 Joule

Average magnitude event of the day: 2,761


[bron]

Ship navigates close to El Hierro active vent

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The INVOLCAN continues to record an increase in the diffuse emission of CO2 by the volcanic system island of El Hierro

The diffuse emission of carbon dioxide (CO2), at present, the volcano island of El Hierro reaches 2398 � 115 tons per day

Since last July, scientists at the Institute of Technology and Renewable Energies (ITER), an agency of the Cabildo of Tenerife, and is now part of volcanological Institute of the Canaries (non-tip) have conducted numerous scientific surveys of diffuse emissions volcanic gases that have materialized over the entire surface of the island of Isla Meridian. To date, the results reflect the record of an upward trend of the diffuse emission of carbon dioxide (CO2) into the atmosphere by the volcano island of El Hierro has reached 2398 � 115 tons per day, an amount equivalent to almost 7 times the normal average value considered for the diffuse emission of carbon dioxide (CO2) in the island of El Hierro (345 tonnes per day).

This increase in the diffuse emission of carbon dioxide (CO2) shows that the pressure of carbon dioxide (CO2) in magmatic-hydrothermal system existing in the island of El Hierro is increasing probably due to magma movement from positions more shallow depth favoring exsolution of carbon dioxide (CO2) dissolved in silicate melts (magma).

The scientific purpose of these campaigns is to investigate spatio-temporal variations of the diffuse emission of carbon dioxide (CO2) into the atmosphere by the volcanic system of El Hierro island since the results thereof can not be obtained through networks permanent instrumental analysis contribute to the evolution of the current eruptive phase is occurring in El Hierro. On the other hand, it is widely accepted that the gases are the driving force of volcanic eruptions and the importance of carbon dioxide (CO2) in volcanic surveillance programs since not only is the second major component of volcanic gases, after steam but its low solubility in molten silicitados (magma) that favors carbon dioxide (CO2) to escape with their ease of volcanic systems in depth.

These scientific surveys have failed to materialize due to MAKAVOL project "Capacity Building of R + D + i + d to contribute to the reduction of volcanic risk in the Macaronesia (MAC/3/C161)" which is being co-funded by the Transnational Cooperation Programme of the European Union Madeira-Canary-Azores (MAC 2007-2013) and the collaboration of the Island Councils of Tenerife and El Hierro.

INVOLCAN is an institution demanded unanimously by the Senate (2005), Parliament of the Canary Islands (2006) and House of Representatives (2009) with the aim of contributing to improving and optimizing the management of volcanic risk in Spain.

Picture Pie
Temporal evolution of the diffuse emission of carbon dioxide (CO2) in the island of El Hierro (red circles) recorded by the Involcan and the daily number of earthquakes located by the National Seismic Network (IGN).

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Update 29/11 – 11:26 UTC
User Martin Rey has traced the ship currently navigating in the stain area
New oceanographic boat on La restinga th "Sarmiento de Gamboa".. 70m, its the BEST oceanographic boat that can be send, i think. It's called a "grand Cientific Instalation" by CSIC, its owner.


Update 29/11 12:18 UTC
It is not official, but due to the many ups and downs along the stain, we are almost sure that the Sarmiento de Gamboa is mapping the sea floor very carefully.
- Todays webcam image is rather complicated with a number of stains. We will need an image from a helicopter to find out whether these are Jacuzzis or patches of earlier emitted material.

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NOTE AVCAN 352 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 29 November 2011-22:00 h peninsular - seismic-volcanic activity continues to moderate-high, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude that has remained stable since the last note, and small oscillations and explosions, possibly hydromagmatic (by the way the pattern has repeated explosions ever closer, each hours approx). The magnitude of the earthquakes between 2.2 and 1.0. New earthquakes 4. Depths to 15, 16, 18 and 22km. The day before yesterday 16. Yesterday 23. Now go 8. A total of 11,869 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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The volcano of La Restinga eject large rocks again

The volcano has returned to La Restinga eject large chunks of solidified lava. The focus cameras 24 hours a bubbling area captured from the first morning, however, "were no more than 20 or 30 rocks" that emerged, says a spokeswoman for the National Geographic Institute (IGN), Carmen Lopez .

A IGN researchers did not give time to collect samples because they could not approach the area due to the strong prevailing wind and the rocks sank quickly, its large size. Carmen Lopez and IGN technicians arrived near the eruptive Salvamar aboard and found that washes out "smoking" in the midst of a "much bubbling" by the emission of "greenhouse and very fine and dense material."

The expulsion of solid material lasted less than two hours. At the moment only seen a bubble in the focal zone eruption.

La Restinga, El Hierro 1st December 2011 8:00 am - 9:30 am

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Graphic which aims to present each day as if there had been an earthquake and the earthquake alone would be equivalent to the sum of the rest of earthquakes a day.
This is to compare the energy released (presented as magnitude), with the average depth of daily events, the average magnitude of the events and the number of events have occurred in the day.
To calculate the average depth, it is weighted by the energy released by each event. (JR)

[bron]

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NOTE AVCAN 362 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - DECEMBER 04 2011-22:00 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the del Golfo marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude which remained stable since the last, least the last 2 hours starting at 7:50 p.m. or so where it has doubled in intensity by a possible jam in the pipe and swings and more explosions, possibly hydromagmatic. The magnitude of the earthquake only 1.4. New earthquakes 1. Depths at 17km. Before yesterday 5. Yesterday 3. Today van 2. A total of 11,909 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).
[bron]

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The diffuse emission of CO2 by the volcanic system of El Hierro island falls under the INVOLCAN

This downward trend since late November until now arriving at 1560 � 59 tonnes per day

Since last July, scientists at the Institute of Technology and Renewable Energies (ITER), an agency of the Cabildo of Tenerife, and is now part of volcanological Institute of the Canaries (INVOLCAN) have conducted numerous scientific surveys of diffuse emissions volcanic gases that have materialized over the entire surface of the island of Isla Meridian. The results show a downward trend in the diffuse emission of carbon dioxide (CO2) into the atmosphere by the volcano island of El Hierro since late November, when it came to achieving the 2398 � 115 tons per day, up to now been recorded an emission rate of 1,560 � 59 tonnes per day.

This record to the bottom of the diffuse emission of carbon dioxide (CO2) in turn implies that the pressure of carbon dioxide (CO2) in volcanic-magmatic system existing in the hydrothermal-island of El Hierro should not continue to grow as well it might be inferred during the observation period was experiencing an increase in the diffuse emission of carbon dioxide (CO2).

The scientific purpose of these campaigns is to investigate spatio-temporal variations of the diffuse emission of carbon dioxide (CO2) into the atmosphere by the volcanic system of El Hierro island since the results thereof can not be obtained through networks permanent instrumental analysis contribute to the evolution of the current eruptive phase is occurring in El Hierro. On the other hand, it is widely accepted that the gases are the driving force of volcanic eruptions and monitoring of carbon dioxide (CO2) in volcanic surveillance programs is very important because not only is the second major component of volcanic gases after water vapor, but also because of its low solubility in molten silicitados (magma) favoring the carbon dioxide (CO2) to escape with their ease of volcanic systems in depth.

These scientific surveys have failed to materialize due to MAKAVOL project "Capacity Building of R + D + i + d to contribute to the reduction of volcanic risk in the Macaronesia (MAC/3/C161)" which is being co-funded by the Transnational Cooperation Programme of the European Union Madeira-Canary-Azores (MAC 2007-2013) and the collaboration of the Island Councils of Tenerife and El Hierro.

INVOLCAN is an institution demanded unanimously by the Senate (2005), Parliament of the Canary Islands (2006) and House of Representatives (2009) with the aim of contributing to improving and optimizing the management of volcanic risk in Spain.


Picture Pie
Temporal evolution of the diffuse emission of carbon dioxide (CO2) in the island of El Hierro (red circles) recorded by the non-tip and the daily number of earthquakes located by the National Seismic Network (IGN).
[bron]

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The Involcan shows a decrease in the diffuse emission of CO2 by the volcanic system


Scientists at the Institute of Technology and Renewable Energies (ITER), an agency of the Cabildo of Tenerife, and is now part of volcanological Institute of the Canaries (Involcan), indicate a downward trend of the diffuse emission of carbon dioxide (CO2) into the atmosphere by the volcano island of El Hierro since late November, when it came to achieving the 2398 � 115 tons per day, up to now been recorded an emission rate of 1,560 � 59 tonnes per day.
This record to the bottom of the diffuse emission of CO2 in turn implies that the pressure of CO2 in the system magmatic-hydrothermal volcanic-existing in the island "should not continue to grow as well it might be inferred during the period of observation was experiencing an increase in the diffuse emission of CO2. "

The Involcan said in a statement that the purpose of these campaigns is to investigate scientific spatiotemporal variations of the diffuse emission of carbon dioxide into the atmosphere by the volcanic system since the results can not be obtained through permanent instrumental network developments contribute to the analysis of the current eruptive phase is occurring in El Hierro.
[bron]

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Spains National Geological Institute (IGN) Scientists, observing seismic and volcanic activity on the Canary Island of El Hierro have recorded just 2 earthquakes over the course of the last 24 Hours (14.00 hrs Tuesday - 14.00 hrs GMT Wednesday).

Activity has fallen considerably over the last week, with Earthquakes numbering between 2 and 4 per week, compared with an average of 12 per day around one month ago.

As in previous days and weeks, these two Earthquakes took place in and around the El Golfo bay area, off the coast of Frontera to the north of the Island. The Magnitudes recorded registered 1.6 and 1.9 on the richter scale, at depths of 23km and 15km respectively.

Meanwhile, scientists observing the underwater Volcanic eruptions in the Las Calmas bay area, off the coast of La Restinga on the south of the island have told PEVOLCA that the temperature of the sea around the `jacuzzi is beginning to stabilize. Temperatures peaked on the 6th of November with a maximum recording of 30.9 Degrees, but have now returned to an average of 21.3 Degrees.
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VUELO CIENTÍFICO INVOLCAN - GC 291111 - VOLCÁN SUBMARINO DEL HIERRO - SARMIENTO DE GAMBOA - PANCAM

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NOTE AVCAN 369 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - DECEMBER 08 2011-12:00 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with high amplitude, unstable and some explosions, possibly even at 04:30 h hydromagmatic where under almost minimum and since then tends to rise and become unstable again. Today has been smoldering pyroclastic output from early in the morning. The magnitude of the earthquake only 1.8. New earthquakes 1. Depth to 22 km. Before yesterday 2. Yesterday 2. Today they 1. A total of 11,919 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).
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Slightly increase the tremor and the stain of La Restinga

The National Geographic Institute (IGN) has confirmed the Civil Protection Plan for Volcanic Risk (Pevolca) yesterday only two earthquakes were located in the area of the Gulf, northwest of La Frontera, with magnitudes of 1.9 and 1.6 on the Richter scale at a depth of 15 and 17 kilometers respectively. None of them was felt by the population. In total, since the day July 17, 2011 11 926 events have been found.
According to IGN, the level of tremor increased in amplitude around 22:00 hours, at which time there was a greater pulse length. Since then remained stable at a level slightly higher than the beginning of the day. As for the studies of ground deformation during the day yesterday continued the same pattern of distortion of previous days, reflecting stability in the components horizontal and vertical component deflation of all stations in the south and east of the island regard to the stain of La Restinga, it is noteworthy that there was an episodic emission steaming lava fragments, but of much less importance than the previous day . IGN adds that the vessel 'Adhara' Maritime Rescue attempted to collect samples but it was not possible due to the remoteness of the area in the emerging area with clean water surface. The spot had a large area throughout the day.

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NOTE AVCAN 370 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - DECEMBER 08 2011-23:00 h peninsular - seismic-volcanic activity continues to moderate. Continue an important sign of volcanic tremor in the Restinga area, with high amplitude, unstable and some explosions, possibly even at 04:30 h hydromagmatic where under almost to a minimum and since then tends to rise and become unstable again, making more consistent in the last hours. Today has been smoldering pyroclastic output from early in the morning. No new earthquakes today at Hierro and vicinity. Before yesterday 2. Yesterday 2. Today they 1. A total of 11,919 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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NOTE AVCAN 371 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - DECEMBER 09 2011-09:00 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude that remains slightly higher and slightly unstable and some explosions, possibly hydromagmatic. The magnitude of the earthquakes between 2.0 and 1.8 New earthquakes 2. Depths to 21 and 23km. Before yesterday 2. Yesterday 2. Today they 1. A total of 11,921 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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Op zaterdag 10 december 2011 13:08 schreef Asphalt het volgende:
In januari ga ik een weekje naar Tenerife, vandaar uit een dagje naar El Hierro met de veerboot.
Genoeg te zien tegen die tijd als ik de post hierboven moet geloven

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Op zaterdag 10 december 2011 16:13 schreef TARAraboemdijee het volgende:

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Hij zegt toch ook dat hij een dagje El Hierro gaat doen?

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NOTE AVCAN 376 - EARTHQUAKE ACTIVITY-VOLCANIC - IRON ISLAND - DECEMBER 11 2011-22:00 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with an amplitude that remains upward (trend in which the last 72 hours and where the intensity has doubled) and presents a growing number explosions, possibly hydromagmatic, every few minutes, a typical strombolian behavior for which establishes a balance between water inlet and outlet of gases in the exhaust duct so that it pulses like a geyser. No new earthquakes located. Before yesterday 2. Yesterday 0. Today is 1. A total of 11,923 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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Update 12/12 -13:57 UTC
- As we are currently in a submarine eruption phase with hydromagmatic bursts, we have searched and found a scientific study about such action. In 1984 Kenneth H. Wohletz and Robert McQueen from the USA Los Alamas National Laboratory wrote a paper with the title : “Experimental Studies of Hydromagmatic Volcanism“ [PDF]. We encourage people who want to learn more details about the current phenomena, to read (at least some parts) of this article.

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NOTE AVCAN 377 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - DECEMBER 12 2011-11:00 h peninsular - seismic-volcanic activity continues to moderate, with seismicity in the Gulf marine area. Continue an important sign of volcanic tremor in the Restinga area, with a base noise amplitude is maintained upward (trend in which the last 3.5 days and where the intensity has doubled) and ... presents a increasing number of explosions, possibly hydromagmatic every few minutes strombolian typical behavior for which establishes a balance between water inlet and outlet of gases in the exhaust duct so that it pulses like a geyser. No new earthquakes located. Before yesterday 0. Yesterday 1. Now go 0. A total of 11,923 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).

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Update 12/12 -14:58 UTC
The amazing NASA Satellite MODIS picture taken at 11:55 UTC this morning (3 hours ago) is showing a cloud column on the exact place of the vent towards the island. Even we do not believe it ! Is must be a coincidence and if not than we have detected the steaming vent waters. The image cannot have been photoshopped as it has been extracted directly from the NASA website (thanks to Julio del Castillo Rivero for sending us the NASA link).