El Hierro eruption (continued ? 2)Update 29 February: There was an earthquake just after 5am yesterday morning with its epicenter east of La Restinga, i.e. between El Hierro and Tenerife. There is now a stain in the area, as shown in the map below, which suggests there might be another vent in this area. Update 28 February: The main cone [...]
Source: El Hierro eruption (continued ? 2) (http://www.janetanscombe.com/news/el-hierro-eruption.html)
El Hierro eruption (continued ? 2)Update 5 March: The science committee says that the volcano, which started erupting on 10 October, has died. The decision to make the announcement was agreed unanimously by the experts. In what must have meaning for the scientists, if not for the public, they say that the "eruptive process continues" and that scientific vigilance will [...]
Source: El Hierro eruption (continued ? 2) (http://www.janetanscombe.com/news/el-hierro-eruption.html)
El Hierro eruption (continued ? 2)Update 6 March: The red alert for the Las Calmas sea area of the eruption has been reduced to yellow. The rest of the island remains on yellow alert. The restrictions on Arenas Blancas, Tacorón and Playa de Los Mozos will be relaxed as soon as a new document is released giving details of a [...]
Source: El Hierro eruption (continued ? 2) (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Capitanía Marítima de Santa Cruz de Tenerife has reduced the maritime exclusion zone to a radius of just half a mile around the volcano emission point south of La Restinga. The sector is defined as a circle drawn with its centre at latitude 27-37.18 N and longitude 017-59.58W – as per the map below. The decision was taken in the wake of Pevolca's reduction of the alert level. In the newly reduced exclusion zone, all fishing and water sports, including diving, are banned. Any navigation within the zone must be with prior authorization from the Capitanía Marítima. JAA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
(http://www.janetanscombe.com/wp-content/uploads/0.5k-exclusion-zone-la-restinga-490-x-345.jpg)
Quote from: aspasia on Fri 9 Mar 2012, 21:00Capitanía Marítima de Santa Cruz de Tenerife has reduced the maritime exclusion zone to a radius of just half a mile around the volcano emission point south of La Restinga.
Hey - isn't it about time you went metric?
Quote from: Perikles on Sat 10 Mar 2012, 08:22
Hey - isn't it about time you went metric?
What's metric? :confusedsys:
:039:
Just quoting ... nautical types don't do metric it seems ... ::)
Finally, after weeks of calm, El Hierro's eruption alert status has been returned to green. Pevolca and the Canarian Government have now removed the yellow alert, thereby confirming the return to normality ... and the island's survival after months and months of tension with the Las Calmas sea eruption. In the end, there was no new island, no new land mass, but El Hierro is the youngest Canarian island. Who knows what will happen in future weeks, months and years ... or even decades. The yellow alert has, for the moment, been kept for the sea area around the volcanic cone.
It's back. The Frontera area had five tremors this morning, one of which was felt by the public. Within just 25 minutes between 07.18 and 07.43, the first four were registered between 1.6 and 2 on the Richter scale; the fifth was registered at 12.45 with a magnitude of 2.9 and an epicentre on the coast near to the Valle del Golfo. All occurred at a depth between 17 and 20 km, says IGN.
Actualidad Volcánica de Canarias (AVCAN), linked to the Asociación Vulcanológica de Canarias, has confirmed that the tremors indicate a magmatic origin and, naturally, a possible pressurization which, if it were to continue, would cause more seismic activity in the area. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Ooh how exciting!!! :08: :clap:
IGN registered eleven tremors between 4.30 am and 8am this morning in the general La Frontera area. They ranged between 1.7 and 2.8 on the Richter scale at a depth of between 20 and 24 km. It doesn't appear that any of the activity was felt by the public. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
IGN recorded another cluster of tremors between 6pm yesterday and 2.50 this afternoon. There were 16 in total, all between 1.6 and 2.3 degrees on the Richter scale and at a depth of between 15 and 19 km; 14 of them occurred within the space of two and a half hours, between 9.52 and half past midnight, and all but one were in the El Golfo region – the last one was northeast of Valverde. None were felt by the public. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
IGN has recorded more than 60 tremors in El Hierro since 9.30 last evening. Three of the stronger ones have been felt by the public, the largest was just after 9am this morning, of 3.8 on the Richter scale, at a depth of 19 km. Geologists are following the evolution of the situation in case a new eruption phase is about to start.
(http://www.janetanscombe.com/wp-content/uploads/hierro-IGN-june-2012.jpg)
Ooh how exciting! :clap:
117 tremors since midnight is the count from El Hierro as at 1.30 this afternoon. Six have registered either 3 or 3.1 on the Richter scale: one at 2.41am, then two within a minute of each other at 4.10 and 4.11am, others followed at 8.40, 8.49 and 10.40am. All have been at a depth of between 18 and 20km. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
It's starting again! :happydance:
Quote from: Sabrinova on Tue 26 Jun 2012, 16:24
It's starting again! :happydance:
It didn't really start much last time.
More and stronger - 165 tremors over 1.5 on the Richter scale were recorded today, and between 4.15 and 6pm, nine were registered between 3 and 3.5, several of which were felt by the public. All were located under the peak of El Hierro, and appeared to be moving southwards towards La Restinga, at a depth of between 17 and 23km. Geologists say that since the present quakes started at 9.30pm on Sunday evening, they have not stopped, which is how the last eruption started. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
The Canarian Government, in collaboration with IGN (Instituto Geológico Nacional) and Involcan (Instituto Volcanológico de Canarias), has activated a yellow volcanic alert for the areas of El Julan and La Dehesa, unpopulated regions in the south and southwest of El Hierro. The yellow alert allows for information and the activation of vigilance resources for eruptive processes, said the director general de Seguridad y Emergencias del Gobierno de Canarias, Juan Manuel Santana, who explained that the decision was taken after detecting a significant increase of seismic movement and land deformation, said to have been created rapidly and increasing to 3cm since activity restarted three days ago (in the whole of the previous eruptive process the maximum deformation was 5cm). Experts say they don't expect an eruption imminently, but confirmed there is magma movement – and that the eruption has reactivated. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
A tremor of 4 on the Richter scale was registered this evening at 7.55pm, large enough to be easily felt by the public in the Frontera/El Pinar area, and which set car alarms off in La Restinga. This is the strongest quake since the volcano reactivated. Today more than 160 tremors over 1.5 have been recorded. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
The deformation is now 5cm, equal in just four days to the entire deformation during the previous eruptive process. The energy released is some 420 billion joules, which experts say shows a clear acceleration of the magmatic process. Pevolca says that there have now been more than 750 tremors since the process reactivated on Sunday. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
She's gonna blow! :hyper:
Quote from: Janet on Thu 28 Jun 2012, 12:35The energy released is some 420 billion joules,
...which is equivalent to the chemical energy of about 70 barrels of oil. In volcanic terms this is derisory.
IGN says that the deformation continues to grow, and at the same rate, and is now 6cm, with a centre of pressure in the Las Calmas sea, the site of the previous eruption. Seismic activity remains stable, though more concentrated, and localized slightly to the west of yesterday's registered tremors, in El Julan and the Las Calmas sea. So far, since last Sunday, more than 1,100 tremors have been recorded, of which 144 have been over 2.7 on the Richter scale. Most have been at a depth of around 20km. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Quote from: Janet on Sat 30 Jun 2012, 23:56
So far, since last Sunday, more than 1,100 tremors have been recorded, of which 144 have been over 2.7 on the Richter scale.
:wowspring:
Latest tremor was another strong one, of 3.6 on the Richter scale, just before 10pm.
The deformation is now 7.5cm, a steady and rapid growth, says IGN and Pevolca (Plan de Protección Civil por Riesgo Volcánico). The eruptive process continues, and IGN data indicate the seismicity is localizing in "an extensive area, with greater dispersion and numerous epicentres in the sea". This area is to the west of El Hierro, and includes the area of El Julan and the Las Calmas sea. Since last Sunday, over 1,250 tremors have been recorded, 165 of which have been greater than 2.7 on the Richter scale - one yesterday morning was another large one of 4, but there were several of 3+ too. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
It's always the way. The press had just announced that yesterday's seismicity was reducing when it suddenly stepped up a considerable gear! Last night, indeed, was not only the most active since the eruption restarted, but the most active since July 2011! A chain of tremors, felt throughout the island, among them one of 4.4 on the Richter scale. Between 9pm and midnight, there were 40 or so, 18 of which were over Richter 3. In many areas people left their houses in alarm - this was the case in Sabinosa, El Mocanal and La Restinga, and quakes were felt even in Valverde and Tamaduste, places which had been unaffected to date. Last night's cluster was localized in the Faro de la Orchila and El Julan area. Pevolca is to meet urgently at midday to discuss the new level of activity. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
:hyper: :spingirl: :clap:
Pevolca says that over the coming week further earthquakes in the region of Richter 4.4 are likely, perhaps even reaching 4.5 or 4.6. The pressure of magma has now made the deformation grow to 9cm. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
And now the jacuzzi is back, spotted last evening by an emergency Search and Rescue helicopter. It is some 180m from the coast - Pevolca gives coordinates 27º 4.573 North and 18º03.761 West, and issuing a white mark which is still being analysed. The helicopter should be flying over the scene again as I type (11.30am), equipped with a thermic camera to see if it is an eruptive focal point. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
The GES helicopter flew over the area this morning and scientists from Involcan, with a thermal camera, and from IGN, say they have not observed anomalous parameters in the region where the jacuzzi reappeared yesterday. They say this means there are no significant changes in the active magmatic process, though they will be carrying out continuous analysis. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Quote from: Janet on Wed 4 Jul 2012, 16:36, say they have not observed anomalous parameters in the region where the jacuzzi reappeared yesterday.
I can imagine what they
actually said was "Coño, no veo nada de nada, joder" or something of that ilk. :rofl:
After a relatively quiet few days, another earthquake cluster started around 9.30 this morning. Several have been felt by the public, and one, still to be finally calibrated by IGN, is thought to be in the region of Richter 4. The deformation is now 10cm. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Quote from: Janet on Sun 8 Jul 2012, 13:56. The deformation is now 10m.
OMG We're all going to die :closet:
oh - ok, we're not. :poke:
Quote from: Perikles on Sun 8 Jul 2012, 15:41
oh - ok, we're not. :poke:
You'll look silly now if we do all die :P
His original statement is factually correct. :tiphat:
"It could carry on like this for a year, it could disappear completely, or we could have an eruption". That's the expert view in a situation where all possibilities remain open two weeks after a new magmatic intrusion resurrected seismic activity in El Hierro, a period in which more than 300 earthquakes have been strong enough to be felt by the public. The current situation seems to be periods of calm punctuated every day or so by one or two clusters of strong tremors. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
In other words they know stuff all :whistle:
Quote from: Janet on Tue 10 Jul 2012, 10:50
"It could carry on like this for a year, it could disappear completely, or we could have an eruption". That's the expert view
People actually get paid to say this. :gun07:
Quote from: Perikles on Tue 10 Jul 2012, 16:30
People actually get paid to say this. :gun07:
You're using the gun now, copycat :D
I could do that job! I think I'm quite good at talking without actually saying anything :toothygrin:
Quote from: Sabrinova on Tue 10 Jul 2012, 16:39
I could do that job! I think I'm quite good at talking without actually saying anything :toothygrin:
Of course you are, you are female. :closet:
Quote from: Perikles on Tue 10 Jul 2012, 17:03
Of course you are, you are female. :closet:
Watch it! So's the volcano - you have no idea as to her intentions and can't tell whether she's going to erupt or just keep bubbling away quietly :toothygrin:
There have no earth tremors at all since yesterday morning and experts think the current swarm is therefore over. No doubt this will continue to bubble up periodically now until a proper eruption takes place - who knows when.
Here (http://eldia.es/2012-07-14/ISLAS/1-jefa-Geofisico-Canarias-cree-prensa-aumento-alarma-erupcion-Hierro.htm), the chief geophysicist in the Canaries, somebody who seems to know what she is talking about, is complaining that the press are responsible for winding people up about this non-event in El Hierro, and ruining what little tourist industry they had.
She might be the chief geophysicist but she has no idea of tourism or psychology! Touristic chiefs on the island are milking it for what they can, of course, but the indications seem to be that it has attracted tourists hoping to see an eruption rather than driven them away!
PEVOLCA has now put El Hierro back onto green status, after little activity since 16 July. The alert is over – this time. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
It's been rumbling away on and off for the past six or so weeks, the activity has never completely died away, but today there has been quite a swarm, with 40 earthquakes being registered. One oddity is that they appear to have been at two distinct depths, with shallow weak tremors in the El Golfo bay region, and deeper strong tremors moving south throughout the day and completely under land. Some experts think that this indicates that magma could be moving under the island. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
yesterday's total was 61 tremors. Will be interesting to see if this dies away like the other minor swarms have done over the last couple of months, or whether it heralds a new development or departure.
... and here's IGN's chart of the activity:
(http://www.janetanscombe.com/wp-content/uploads/Eventos_HIERRO_2D-490-x-490.jpg)
110 earthquakes today, one of them early this afternoon registered as 3.2 on the Richter scale which was felt by the public. All of them were under land, beneath the original old crater. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Yesterday's tally in the end was 167 earthquakes, and just between midnight and 7.30 this morning 73 have been recorded, the largest so far today being 2.7 on the Richter scale. Deformations are also increased, northwards around 1.5cm and 2cm vertically.
It's warming up again! :clap:
It would seem that something very hot and very powerful is looking for a way out. Which could be anywhere in the Canaries. Worrying!
Quote from: Guanche on Sun 16 Sep 2012, 10:56
It would seem that something very hot and very powerful is looking for a way out.
Perhaps you should avoid the mutton vindaloo next time :tiphat:
I said 'hot and powerful' not 'hot and painful' ;)
Quote from: Guanche on Sun 16 Sep 2012, 10:56
It would seem that something very hot and very powerful is looking for a way out. Which could be anywhere in the Canaries. Worrying!
Hey, knock it off. I arrive on Friday. :eyepop:
Quote from: Janet on Sun 16 Sep 2012, 09:53
Yesterday's tally in the end was 167 earthquakes
and as of 9pm this evening, today's tally is 185 earthquakes today, still slowly migrating south, still all under land.
Scientists from the Instituto Tecnológico y de Energías Renovables (ITER), which forms part of the Instituto Volcanológico de Canarias (Involcan), have confirmed from the deformation in El Hierro that the eruption has reactivated. Between 13 and 16 September there has been an horizontal displacement northwards of 1.62cm and a vertical displacement of 2.9cm. Yesterday's tremor count ended up at 197; today's was slightly lower, at 105 as of 9pm. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
It's incredible how quickly these phenomena can rise and die away. It seems that this swarm is already dying away, but it shows the pattern for the future, it seems: this is an eruption that will happen at some point. It appears that the magma seeking release from beneath El Hierro is finding two routes of escape, the first in the El Golfo bay region, and the other directly under the island land mass, which of course is the crater part of the old volcano itself. There have been three quake swarms so far, the first one resulting in the eruption in the Las Calmas sea south of La Restinga , the second one was just in the form of tremors that had no surface phenomena, and now this short-lived third one which has seen a clear movement southwards. It will be back ... JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
As I said in my last post on this on 18 September, "it's incredible how quickly these phenomena can rise and die away ... it shows the pattern for the future". And now we have another swarm, with eleven tremors recorded over the last 24 horus under the centre of El Hierro, all moving southwards. None were over 1.8 on the Richter scale. It will become clear over the next day or so whether this builds up into another eruptive stage, or dies away as quickly as the last flurry. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
It's been rumbling away for the last few days, with a 2.6 tremor on Thursday 13th which was felt by the public. Experts say this set generally is showing the same patterns as in the last swarm. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Today has been a very busy day for seismic activity, with 20 earthquakes today in the El Golfo region of magnitudes ranging between 1.5 and 2.5 on the Richter scale. 2012 is ending with a clear swarm, as El Hierro shows that it will almost certainly have more in store during 2013. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
(http://www.janetanscombe.com/wp-content/uploads/Captura13.jpg)
Since the 31st's update, there have been one or two lulls, but generally there are tens of these quakes each day now, all at a depth of between 15 and 20 km or so, and up to a maximum of around 2.5 on the Richter scale, with a general albeit slight increase in strength. What marks this swarm out as interesting is that they're centred on the hitherto less affected north El Golfo region. Yesterday saw quite a strong harmonic tremor, which has almost died away today; experts say that this suggests magma is trying to find a way out and has currently been halted. Only time will tell how and where it will make itself felt next. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
A football-field sized turquoise-coloured patch has appeared off the south coast of El Hierro. IGN says that this is a periodic degassing associated with the eruptive process but does not necessarily indicate a resumption of volcanic activity. The President of the El Hierro Cabildo, Alpidio Armas, has called for calm, and reminded the public that this is not the first time that such patches have been seen in the area. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
I was reading somewhere that they had calculated the mass of lava expelled during this eruption last year, and worked out that it would take about 9,000 similar eruptions to make another island the size of El Hierro. Normally they would be spaced out at about 150 years between each one.
It was in the paper a couple of weeks ago, sorry no link.
After a few days of clustered tremors, there was just one today, but it was strong for this series, at 2.9 on the Richter scale. The earthquake occurred just before 4.30 at a depth of 15km: its epicentre was located off La Restinga on the turqouise patch. Experts say that the harmonic tremor graphs show changes too, and that the episode suggests that something "interesting" is happening. JA (http://www.janetanscombe.com/news/el-hierro-eruption.html)
Quote from: Janet on Thu 31 Jan 2013, 22:30something "interesting" is happening.
I bet that is a rough translation of at least one person's last words in Pompeii, 79 AD. :toothygrin:
IGN's volcanic measurement network has registered a new clutch of seismic activity in El Hierro today with a total of 28 tremors of between 1.9 and 2.6 degrees on the Richter scale. None were felt by the public. The largest of the quakes, 2.6, occurred at 2.29pm to the west of Frontera, under land, at a depth of 20 km. It was followed at 2.42pm by a 1.9 tremor at a depth of just 2km to the north west of Frontera. The rest of the seismic activity was mainly to the northwest of the municipality and to the southwest of El Pinar. There were three quakes yesterday too, the largest of 3.8 degrees on the Richter scale to the west of Frontera, again under land, at a depth of 13 km. IGN says that there have been 30-odd tremors over the last several hours. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
(http://www.janetanscombe.com/wp-content/uploads/Captura-429-x-453.jpg)
There have been around thirty more tremors this evening since my earlier post, most between 1.8 and 2.7 on the Richter scale. The above diagram shows the distribution. Experts say that this latest swarm is showing new magma intrusion between around 16 to 25 km. As they have said before, "something interesting is happening". JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
Yesterday's tally was 143 earthquakes. Today, already by 8am, there had been 24 registered (the registration ignores the minor tremors), the strongest of which was 3.1 on the Richter scale at a depth of between 16 and 18 km. These are occurring under land, though some are in the Golfo area under the sea, as the above graphic from yesterday shows. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
As the experts have said before, the magma is looking for a way out, and is choosing new routes every time its path is frustrated. As such, one of the more interesting elements of these tremor swarms is the way the quakes "migrate": the pattern of movement shows very clearly the new path that the magma is tracing. Now it is clear that the current swarm is moving towards the unpopulated west spur of the island. This swarm of tremors, however, marking a new magma intrusion, seems to be slowing down. Perhaps this path too is blocked. Only time will tell where the magma will try next. One thing seems certain, though, and that is that we have not heard the last of this "eruption".
Experts say that this swarm is dying down now, with just 24 tremors yesterday. Their readings show magma at a depth of 16 to 18 km reaching other channels in a way to the surface. The island's deformation continues as expected, mainly in the east – the opposite side to that where the tremors are taking place: this appears to be because the tremors are releasing pressure, whereas in the east the pressure is building up. Looks like we will now have to wait for the next swarm to give a few more hints of developments. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
There was a spurt of activity last night culminating in a quake of 3.8 on the Richter scale, the strongest so far this year. It was on the western tip of the island at a depth of 18km, and was felt by the public. The deformation in the east also continues. Experts say that the idea that this swarm was dying away may have to be revised. In all, there were 117 tremors yesterday. There have been around 50 today, though that figure will be confirmed tomorrow: all have been around the western tip, with the most powerful registering 2.9 at a depth of 14 km.JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
There were 93 earthquakes yesterday, but today saw 134 up to 7pm, the strongest activity since the start of this swarm. They are gradually getting shallower, into a depth of around 12-14 km, which suggests, experts say, that magma is reaching higher levels. Several have been over 3 on the Richter scale. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
Yesterday's count ended up at 164, the busiest day so far in this swarm by some way. Overnight there were a further 62 tremors over 2 on the Richter scale, hundreds of smaller ones, now getting slightly deeper again back to the 16 -17km depth and moving slightly out to sea off the western tip of the island. The deformation is what is really spectacular, however, according to expert vulcanologists: the west of the island has been forced 2 cm upwards in the last 24 hours alone.
As of 10pm, there have been 148 earthquakes today, those over 3 on the Richter scale being felt by the public. Involcan is sending scientists to the island tomorrow to carry out measurements and oversee analysis systems.
Yesterday's total was 159 earthquakes over 2 on the Richter scale. Today, the biggest quake so far, of 4.1 at 2.41pm, again to the west and under the sea at a depth of 16 km. A further ten quakes over 3 on the Richter scale followed within the next hour, the largest of which was 3.7 at just past 3pm. Many quakes have now been registered today over Richter 3, a clutch of eighteen of them between 3 and 3.9 started the day off around 1am. Accompanying these is a strong upward deformation, which is said to be sufficient to cause some cracks to appear in buildings and infrastructure.
The PEVOLCA committee of insular and regional authorities and scientists is to meet tomorrow to discuss the current crisis. At present they are saying there is no risk to the public, but they will be investigating potential scenarios which might arise in the near future. Experts say that today represents the strongest volcanic activity since the whole eruption started in 2011. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
There were 224 earthquakes yesterday, one of which as we know was 4.1 on the Richter scale, the strongest since the eruption first started. Pevolca met as planned today and have said that there is a strong chance of a 4.3+ earthquake, they think a 75% or so chance, but maintain there is no significant risk to the public, at least not sufficient to warrant extraordinary measures. Although today was slightly calmer, 170 quakes had been recorded by around 7pm, many being felt by the public for minutes at a time, and there were reports of windows vibrating and rockfalls. About an hour ago, at 10pm, however, some quite strong earthquakes were registered, and these are still ongoing as I post at just gone 11pm. The magnitudes have not yet been confirmed. From what information is actually available of this last series, it seems that these stronger quakes are moving southwards and towards the island. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
195 quakes yesterday. Today, we have confirmation that the epicentres are moving back towards the island. At lunchtime today, experts were talking about a slightly quieter day, with about 60 or so quakes overnight and this morning at a depth of 12-15km, the strongest of which was 3.3 on the Richter scale. At 1pm, however, there was a series of Richter 3 tremors, with two around 1.30pm registering 3.7 and 3.9 at a depth of 15km, inevitably being felt by the public. At 3pm, another series of 11 R3+ earthquakes was registered in just an hour. Involcan has released the following photo of the rockfalls in the El Golfo area described yesterday. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
edit: within minutes of posting the above, the strongest earthquake yet has been felt, 4.6 on the Richter scale at a depth of 19km
(http://www.janetanscombe.com/wp-content/uploads/golfo-hierro-rockfalls-27-march-2013-381-x-526.jpg)
Ooh it's getting exciting!! :clap:
The 4.6 was felt beyond the island, in La Palma and La Gomera and even on Tenerife, though experts say this is perfectly normal for such a size. It can stop getting any more exciting now ...
Clearly there is pressure under there trying to get out. I don't foresee a major eruption (but then who has ever?) but it's interesting to note where the Canary vulcanism is currently centered.
I have researched as best I can via internet at the cause, but theories abound with no resolution. The most convincing (to me) is that of a failed arm of the tritypical rift that made the Atlantic ocean - the 'plume' seems contraindicated by the lack of a raised local seabed.
Experts say that there are spectacular earthquakes going on at the moment in the sea west of El Hierro. Another strong earthquake, 4.4 on the Richter scale, has been registered which made chairs and light fittings move and windows rattle. Like the 4.6 a little earlier, it too was felt on other islands. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
As of 6pm there is another series of strong earthquakes shaking El Hierro at the moment, still to be classified by IGN.
Pevolca has issued a yellow alert for the area of Pozo de la Salud towards the south.
and one lane of the Los Roquillos tunnel has been closed as a preventative measure. Also closed are the roads between Cruce de La Tabla and Sabinosa, and the access to Playa La Madera.
Calm, followed by a series of strong earthquakes around 5.30am, followed by a calm spell, and then another series of strong earthquakes from around 8am. That's been the pattern overnight and this morning, many of them over 3 on the Richter scale. Experts say that if these had occurred under land the island would be ringing like a bell. As it is, they are slightly out to sea off the south western tip of the island. I have little doubt that there will be further updates throughout today.
Is El Hierro visible from your house Janet?
yes, at least the outline is visible on a clear day, and it's thrown into quite sharp silhouette at sunsets, particularly in the winter when the sun's further south.
On the very clearest of days I've made out lights there, but you can't really identify anything, and that's only happened about three times since we've been up here. Even on La Palma, particularly on clear summer evenings (sun more northerly) one can make out car lights moving along streets in a town ... it's that clear, even though it's so far away that detail is impossible.
That's not even possible with El Hierro. The barest outline, really, is all we can see of the north east coast (so the area involved at the moment, the south west, is not visible at all).
You'd see a ruddy big volcanic eruption though :D
I bloody hope so! :D
Quote from: Janet on Thu 28 Mar 2013, 10:57
I bloody hope so! :D
Just make sure you keep fresh batteries in your camera. :giggle:
Between 9.15 and 11am there were 15 earthquakes over 2 on the Richter scale, 13 indeed of them being over Richter 3, the strongest being 3.8. At 11 on the dot, a 4.1 was registered.
Involcan has released carbon dioxide readings, which are said to be greatly in excess of normal levels. Some 1,684 ± 72 tons of CO2 per day are currently being released from below El Hierro, a level even stronger than the first and second phases of the eruption last year.
The emergency services have just released this image of the area currently affected by the yellow alert.
(http://www.janetanscombe.com/wp-content/uploads/Captura-490-x-357.jpg)
Yet more calm followed by activity, and a calm-ish evening followed in the last hour and a half, by 10 earthquakes of Richter 3+, the strongest of which was 4.1. There have been 188 earthquakes today ... so far.
There were brief power failures in the west of El Hierro last night, with 64 earthquakes overnight: experts say that there are now so many quakes that IGN is now only listing the stronger ones, so the real number must be in the hundreds. The strongest so far (already) today is a 4.3, and deformation continues to increase which is thought itself now to be causing a separate series of tremors to that of the magma-based quakes under the sea. As at now, 9.30 am, there are said to be strong quakes at a high rate.
Scientists say that the energy released since the start of this latest crisis has exceeded the total energy released during the initial part of the eruption throughout 2011. So far today, there have been 51 earthquakes over Richter 3, eight of them over R4. Naturally the public has felt the tremors. The strongest ones have also been felt on other islands.
After an afternoon of large quakes, the biggest one yet. Direct reports from El Hierro say it occurred at 5.01pm, and really shook property. This quake is being recorded as 4.7 on the Richter scale, but direct reports say it felt bigger than that. It was also felt on La Palma.
(http://www.canarias7.es/fotos/p3/28412.jpg?1049)
this is the sum total of the quakes since the whole thing started ... :-X
:wowspring:
There were 190 earthquakes registered yesterday, but as said before, these are just the larger ones now. Experts say that in reality there will be over 1,000 if all tremors are included. Fourteen of the quakes were Richter 4 or above, the largest being the 4.7 at 5pm, though locals are adamant that it felt much stronger than this - that could be the effect of the specific location or depth of the quake, perhaps, but its effect was clearly major. So far today, 55 earthquakes have been recorded, and there is confirmation that El Hierro, as an island, has been shifted eastwards by the magma and deformation caused by its pressure.
113 quakes yesterday, and after the excitement of the Richter 4+ quakes of the day before, yesterday seemed like a calm day! If I'd been posting this an hour or two ago, I'd have said that this eruption now seems to be calming down, with just a handful of Richter 3 quakes overnight and early morning, but then at 9.40, a 4.5 was registered in the Frontera area. More details later, of course, but even when this crisis really starts to die away, we need to be aware that it's just dozing, not asleep.
Quote from: Janet on Sun 31 Mar 2013, 11:06but even when this crisis really starts to die away,
For a crisis, it's pretty boring so far.
:021: vulcanological term, apparently ...
:tiphat:
the largest so far. An earthquake measuring 4.9 on the Richter scale was recorded at 11am.
The timings, I've realized belatedly, are official ones and so are mainland Spain times. Canarian time is an hour ahead – so rather than trying to remember to add an hour on each post, and forgetting and so causing confusion, please can everyone just mentally add an hour onto any times posted?
The 4.9 earthquake registered an hour ago is now bringing reports of strong shaking not just in El Hierro, but La Palma too. Many reports also of rockfalls. The quake was at a depth of 20 km and out to sea in the Frontera area.
Quote from: Janet on Sun 31 Mar 2013, 12:26
Canarian time is an hour ahead – so rather than trying to remember to add an hour on each post, and forgetting and so causing confusion, please can everyone just mentally add an hour onto any times posted?
It's the other way round... Canarian times are an hour
behind the mainland, so we need to
subtract an hour from the official times to know the local time here :tiphat:
oh bollocks ... that doesn't work ... :blackcat:
they must have the right local times.
As you were :tiphat:
Do you think i'm watching from a safe enough distance? :undecided:
Quote from: Michael on Sun 31 Mar 2013, 13:56
Do you think i'm watching from a safe enough distance? :undecided:
This is El Hierro, not Yellowstone :giggle:
After a relatively quiet day yesterday, overnight there were two Richter 4 quakes, a 4.4 at 2.45am followed around an hour later by a 4.2 at 3.40.
(http://www.janetanscombe.com/wp-content/uploads/Captura25.jpg)
I don't know who's been aware of, or following, the competition to find NASA's best photo of the earth from space, but the above photo of the La Restinga eruption last year has just won! Not just won, but when it got to the final two against the breaking of Pine Island glacier in Antarctica, it got 91% of the vote! The competition has had five phases each with internet voting week to week on a total of 32 staggering photos for the best image of 2012. The authorities in El Hierro, of course, hope that it will bring some much needed tourism promotion for the island, particularly in view of the recent activity which they fear might have put people off visiting. The latest crisis seems to have died away as quickly as it bubbled up, and will no doubt do so again at some point. I hope this picture will do some sterling work for the island in the meantime! JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
As this crisis appears to die away, Pevolca has said that although there are still some abnormal values, they are lowering the alert level from yellow to green. All roads that were closed have been reopened. Until the next time ...
Maybe it's too soon to say it's over. An earthquake of 4.1 on the Richter scale which was felt by the public was registered on El Hierro at 3.26pm in the sea to the west of Frontera at a depth of 19km. Nonetheless, only three tremors have been registered today, two of them with magnitudes of between 2.5 and 2.8.
Most of the magma intrusion is > 10km.
I would become alarmed if it was < 1km.
There has been ongoing rumbling throughout, but over the last few days it has increased noticeably. It's all still low level, with "weak" tremors, albeit lots of them, but real information is hard to come by: experts say that official graphs are "useless" because "amplitude of the events has been scaled back so strongly that even an earthquake is hard to see. This kind of behavior of the authorities was in earlier times reserved for some dictatorship states who did not want to get bad news´outside the country." Something nonetheless seems to be building up again. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
(http://www.janetanscombe.com/wp-content/uploads/Captura-490-x-443.jpg)
There have been continuous tremors over the past month or so since the last update below, but they've all been quite low level, just rumbling away. Yesterday, however, just before 1.30pm, there was a 2.5 magnitude earthquake at a depth of 11km right under the centre of the island. It was felt by some of the public. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
(http://www.janetanscombe.com/wp-content/uploads/tremor-el-hierro-13-nov-490-x-398.jpg)
It has been rumbling on steadily over the past several months, with occasional tremors of up to 2.5 or so on the Richter scale that are felt by the public. Today, however, a quake of 3.3 shortly before 2pm was felt widely through El Hierro: it was at a depth of 10.8km between Frontera and El Pinar. There was an aftershock three minutes later of 2.2 on the Richter scale at a depth of 12km. The pair were part of a cluster registered from 1.30pm, and followed another cluster in the early hours of the morning. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
A video here (http://www.canarias7.es/), 2 years after the start.
Totally off-topic, but when starting the video, there is an advertisement which I find quite shocking. Woddya think?
I had loads of trouble getting the video to play, but when I did, saw no ad. Just pretty fish.
I don't get ads, my browser blocks them. I can't get the video to play either though :017:
Edit: Got it, wow. I like the purple fishies :D No ads though. Before you tell us what it is make sure it isn't placed by Google Adsense :giggle:
(http://www.janetanscombe.com/wp-content/uploads/hierro-tremors-22-dec-2013.jpg)
It's been fairly quiet of late, indeed over the last few weeks it's been very quiet indeed, but it's woken up to give a Christmas message. A new cluster of tremors has been registered over the past 24 hours which experts say looks like a preliminary to something stronger. The activity started in the Mar del golfo (see the green dots in the above image) with 11 tremors at a depth between 14 and 16 km, and then started to move under the island over the last several hours (red). The highest tremor recorded at present is 2.8 on the Richter scale: vulcanologists say that the magma is still trying to find a way out. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
And in the last hour, two have been registered over 3 on the Richter scale, and I've just received an email from Bob in El Hierro (has posted in my comments) who says that they are "having another house shaking session, two felt in Valverde around 16.30 hours".
(http://www.janetanscombe.com/wp-content/uploads/hierro-23-dec-490-x-314.jpg)
There have been 121 earthquakes over 1.5 on the Richter scale in the last 24 hours, all of them at a depth of around 14km. Vulcanologists say that a new episode of magma eruption has now started, confirmed by deformation data supplied by Involcan: upward deformation is at least 2cm. At present, the tremors have headed to, and are clustering below, the El Pinar area (red on the above IGN graphic). Seismologists say that at the present depth, there is no immediate danger, but that quakes are expected to grow stronger. Depending on the magma's success in gaining release, too, the movement may change direction. Watch this space, as they say. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
A widely-felt earthquake in El Hierro this afternoon has been confirmed by IGN 5.1 on the Richter scale. It was also felt in the north of Tenerife and La Palma.
The earthquake was at 5.46pm to the west of the municipality of Frontera, at a depth of 15km. It was widely felt and locals, said to be alarmed, described the effect as a very strong shaking. Five minutes later another two tremors of 2.9 and 2.7 on the Richter were recorded, though these weren't felt by the public.
Quote from: Janet on Fri 27 Dec 2013, 18:43
The earthquake was at 5.46pm .... It was widely felt and locals... described the effect as a very strong shaking. .
Amazing :eyepop: Who would have guessed?
Despite what *some people* think, that's a fairly big earthquake.
Signed, Survivor of Many Earthquakes
Further quakes of 3.7 and 3.3 were recorded last night (11pm and just before 1am) in the same place (10km out to sea to the west of El Hierro) at depths of 20 and 12 km. These are just the "relatively strong" ones - several others in the mid-2 Richter range were also registered Deformation in the El Pinar and La Restinga area is now said to be "strong", giving a total lift of 10cm in this cluster. HERE (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
Avcan is reporting a new magma intrusion in El Hierro which has resulted in some 25 tremors since early this morning. Seismic activity has been building up somewhat over the past few days, but as of 5am this morning a cluster of earthquakes has been recorded, almost all of them between 1.8 and 2.3 on the Richter scale. All were located in the eastern wall of the Golfo area of the La Frontera municipality, between the Roques de Salmor to the los Roquillos tunnel. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
The cluster is now a swarm, with the largest tremor overnight at 2.4 on the Richter scale. All the quakes are said to be deep at 15 and 20 km, and have slowly shifted north from the El Golfo area towards Valverde and then turned back south towards the centre of the island, towards an area previously unaffected. This fits experts' views that the magma is continuing to seek new ways of reaching the surface. Over the last hours of the night the rate of tremor increased, with some 227 being recorded over the last 24 hours. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)
[attachimg=1]
An earthquake of 2.4 on the Richter scale at a depth of 33 km was registered by IGN to the west of El Hierro last evening minutes before 8pm. It was followed at 10.36pm by another of 3.8 at a depth of 15.6 km in the same region. Avcan (Actualidad Volcánica de Canarias) says that it was felt throughout the whole of the island. JA (http://www.janetanscombe.com/news/el-hierro-eruption-continued-3.html)