Red alert for volcanic eruption in El Hierro (original post)

Red alert for volcanic eruption in El Hierro (original post)

Update 26 October: Seismic activity over the past several hours has intensified and become destabilized, with “explosions” that do not correspond to tremors. IGN has detected 8 new tremors since the early hours of this morning, all with an epicentre to the northeast of Frontera. The largest was minutes after 7 o’clock this morning, and registered 3.1 on the Richter scale. All except one were at a depth of at least 20 kilometres, and 3 were measured over 2.5 on the Richter scale. The seismic activity marked in red in the graphic above shows the El Golfo region where the action has now moved to.

Update 25 October: While results are still being analysed, and the tremors continue to the centre and west of the island, scientists aboard the science ship, the Ramón Margalef, have released the following digital image showing the new volcano that has formed to the south of El Hierro. The base is 300 metres deep, with a width of 700 metres; the cone has a height of 100 metres with a crater mouth 120 metres wide.

Update 24 October: It seems, pending results from the science ship, that the La Restinga eruption could actually be settling down in a “termination period”, even though it is still emitting lava, but the seismic activity over the last 36 or so hours is causing concern, not least because the focus seems to have shifted.

Current attention is focused on Frontera and El Golfo, areas in the centre and west of the island, where all these tremors have been located, the majority in the sea, and aligned NNW-SSE. Over the past 24 hours, 78 have been registered, the largest being 3.1 on the Richter scale and at a depth of 20-25 kilometres.

How this new shift of focus will develop is currently unknown.

Update 23 October: After around 50 tremors since yesterday afternoon, two of them large enough to be felt by the public, bubbles are appearing on the sea’s surface once again. The Government says it will make a reconnaissance flight and analyse data before declaring it has reactivated, but present indications are that the underwater volcano could be starting up again.

Update 21 October: Following a meeting of Pevolca, La Restinga residents have now been allowed to return home, except for those with limited mobility. In addition, the Los Roquillos tunnel will re-open between 8am and 8pm. Scientists say that the decision was made based on the reduction in seismic activity, though they stress that the eruption is not over, and that the area remains on level 1 of red alert.

Update 19 October 10pm: Scientists from IGN and CSIC have held a press conference to explain that from the reduction in seismic activity and other readings it now seems likely that this eruptive phase is concluding. The situation will continue to be closely followed in the hope that values return to those of July, though it is still possible that this is merely a temporary pause in the stages foreseen for a full eruption above the surface of the sea. It will still take a few days to be sure, and at present, all that can be said for certain is that the present process is losing strength for the moment.

Update 19 October: For the last 24 hours or so all has gone very quiet on El Hierro, with seismic activity down, and the bubbles and pyroclastic material in the sea all having stopped. Scientists say it will be another 48 hours before they can say whether this represents a genuine stoppage in the volcanic process, or whether it indicates new developments or a displacement of seismic activity at a different focal point.

Meanwhile, La Restinga residents are still evacuated and have not been given permission to return to their homes.

Update 17 Oxtober 11pm: The proposed permission for some residents to return to La Restinga has been postponed given the state of the sea and the possibility that volcanic material and gases will infiltrate the port.

Meanwhile, the Volcanic Risk Co-ordination Committee has established a no-fly zone of 5 nautical miles around the eruption zone. Military or scientific flights will be allowed into the area.

Update 17 October 3.30pm: A few times now I’ve mentioned the El Hierro eruption in comparison to the Teneguía eruption in La Palma in 1971, and indeed this is the comparison the scientists are using: the El Hierro eruption is now said to be bigger, with 50 million cubic metres of magma as opposed to Teneguía’s 40 million. So, I thought it might be useful if people could actually see what Teneguía was like …

[youtube]http://www.youtube.com/watch?v=DodH-NdUNRo&feature=related[/youtube]

Update 17 October: Scientists are now saying that they believe this new volcano has more magna than La Palma’s Teneguía did in 1971. Teneguía expelled 40 million cubic metres of magma over 24 days, but from complex mathematical calculations and analyses based on readings, soundings and imagings, they anticipate the new volcano will expel 50 million cubic metres of lava over a month to six weeks.

Update 16 October 11pm: Scientists at CSIC are now not only convinced that the eruption is of a Surtseyan type, but think that if the process goes as expected, it could culminate with a new island a couple or so kilometres from La Restinga, perhaps even within the next fortnight. Everything depends, it seems, on the amount of magma that the volcano that we now know to be under the sea has to expel.

CSIC says that in a week and a half, maybe two, we might be able to see the new volcanic crater, and this might be erupting. This would be similar to the Teneguía eruption in La Palma, which lasted 20 days.

Update 16 October: Canarian President, Paulino Rivero, has announced that Pevolca will allow La Restinga residents to return to their homes in the next 24 hours, though the elderly and children will have to remain evacuated.

The Los Roquillos tunnel has also been re-opened with certain restrictions and control points. This has been allowed because the release of pressure through the magma fissure has reduced the intensity of earth tremors.

Meanwhile, IGN and CSIC scientists think it likely that the underwater magma will reach the surface. The four-stage eruption is still being foreseen, with ash expelled to a height of 4 or 5 kilometres; this should then disperse in the air, a situation that would be more dangerous for the public, said Sr Rivero. After this, the explosivity should diminish and become an eruption proper similar to La Palma’s Teneguía in 1971.

Before the ash ejection, a column of steam is anticipated which should last several hours. Scientists say this will allow sufficient time to re-evacuate residents of La Restinga.

El Hierro is now on the top level 1 of Red Alert.

[youtube]http://www.youtube.com/watch?v=42H2znxGyhg[/youtube]

Update 15 October 11pm: Scientists from IGN and CSIC say that this eruption is of the Surtseyan type composed of four phases, depending on the amount of magma there is to be expelled. This Surtseyan type is named after the Icelandic island of Surtsey … and indicates a spectacular eruption with violent explosions caused by magma coming into contact with shallow water. The above video shows the type of explosion with the birth of Surtsey itself in 1963.

The first phase, as seen today, involves the expulsion of lava bubbles which carry gas and which sink once the gas is lost. The second stage involves a white steam column and leads to an explosive phase three which in turn, in phase four, results in the creation of a small island spewing flowing lava. This will all be visible, it seems, once the present eruption in phase one rises to a depth of 60 metres.

[youtube]http://www.youtube.com/watch?v=DHagsS9WmzU[/youtube]

Update 15 October 14.45pm: An hour and a half ago, at 1.15pm, those who had been permitted to have access to La Restinga, to retrieve personal belongings for example, have been ordered to get away from the coast. The complete eviction order followed a new eruption just 2.5 kilometres off the coast; it is thought to be at a depth of around 600 metres, and is accompanied by intensified tremors.

The authorities have ordered everyone away from the coast, including the police checkpoint to stop people approaching La Restinga, in fear of a pyroclastic eruption, material from which is now visible on the surface of the sea itself, as in the above video. Flying over the area has also been prohibited, and the ship currently investigating the magma flow visible on the surface has been ordered to get away from the spot urgently.

[youtube]http://www.youtube.com/watch?v=3LzioTeVqGo[/youtube]

Update 13 October: There are now “at least two” eruptions going on under the sea, at a depth of at least 150m, and the volcanic activity is leaving a trail that is now visible from space. Above is a video filmed from a plane flying over the area, now nearing the coastline.

IGN (National Geographic Institute) and CSIC (Centre for Scientific Investigations) have said that at present the eruption is continuing apace but with stability. Ramón Ortiz, from CSIC, said that there is a fissure several kilometres in length which is erupting at various points. As such, the marks visible on the sea’s surface are useful in showing direction and focus points, but what is really important is how the eruption now evolves. Sr Ortiz said that scientists are considering three possibilities: that there will be an eruption on the coast, inland, or out at sea.

Meanwhile, a boat, the ‘Ramón Margalef’, from the Spanish Oceanographic Institute is currently heading for El Hierro from Vigo to join a Canarian Marine Science Institute craft, the Profesor Ignacio Lozano. The CMSI boat will arrive at El Hierro tomorrow, while the Margalef is expected on Tuesday. Together, they will employ a robot submarine to analyse the eruptions. El Hierro Cabildo, Gobcan

Update 11 October: El Hierro is now on red alert for volcanic eruption. Pevolca (Plan Específico de Protección Civil y Atención de Emergencias por Riesgo Volcánico) raised the red alert at 1.20pm specifically for the area of La Restinga. The emergency is being covered by the consejero de Economía, Hacienda y Seguridad, Javier González Ortiz, at the Centro Coordinador de Seguridad y Emergencias 1-1-2 de Santa Cruz, and the director de Seguridad y Emergencias in CECOI en Valverde, the El Hierro capital.

The decision was taken on the basis of a report from the Instituto Geográfico Nacional (IGN) at 1.20pm after tremors were felt in La Restinga. The eruption, out to sea at present, is thought to be approaching land, and nearing the surface as it does so. For this reason, the population of La Restinga has been evacuated as a precuationary measure to the football field, which is the place determined by the emergency plan, and the centre the public has been advised of.

Meanwhile in the Madrid Parliament, PM José Luis Rodríguez Zapatero has called a meeting for 7pm tonight (6pm Canaries time) with various ministers and experts to analyse the El Hierro situation. From information currently available, present will be ZP himself; minister of Defence, Carme Chacón; minister of the Interior, Antonio Camacho; minister of Fomento, José Blanco; director of the cabinet, José Enrique Serrano; general chief of defence staff, José Julio Rodríguez; director general of Protección Civil y Emergencias, María Victoria Eugenia Sánchez; chief of operations of the military emergency unit, Emilio Roldán; secretary general of Relaciones Institucionales y Coordinación del ministerio de Fomento, Fernando Puig de la Bellacasa; director general of IGN, Alberto Sereno; and the sub-director general de Astronomía, Geodesia y Geofísica, Jesús Gómez González. Gobcan

Update 10 October 8.45pm: Pevolca has announced a new meeting which is taking place at this very minute: the meeting started at 8pm in the El Hierro Cabildo. There will be a press release when the meeting is over.

Meanwhile, the socio-cultural centre in La Restinga has opened an information centre that will be available to the public at all times.

This afternoon a press helicopter flew over the eruption area and has seen a large number of dead fish floating on the surface of the sea.

Update 10 October 8pm: The President of the Canarian Government, Paulino Rivero, has said from Brussels that he applauds the people of El Hierro for their exemplary comportment throughout the whole of the volcanic crisis that is developing through the island.

Sr Rivero said that he particularly valued the calmness with which the public is facing the process, especially since the abundance of information can distort or amplify the gravity of what is happening.

The President stressed that the Government is operating under the plan already activated and was following all protocols applicable to the yellow alert. Sr Rivero said that there was no risk to the public and that El Hierro was being perfectly monitored and permanently controlled in case of any departure from what was expected in the process.

Update 10 October: Unconfirmed reports were received this morning from four boats to the maritime authorities that there was volcanic activity at a depth of some 500 metres 5 kilometres to the south of La Restinga. This is now confirmed by IGN: there is an undersea eruption at a depth of 900 metres 4 kilometres to the south of La Restinga believed to be being produced through the fissure caused by the 4.3 Richter scale tremor on Saturday evening. Until further analysis, scientists do not know whether the eruption is of gas or lava. It is the first eruption in Spain since the Teneguía eruption in La Palma in 1971. A government statement is expected once it has been briefed by Pevolca, expected after 7pm this evening.

Update 9 October: Between midnight and 5.43pm today, El Hierro has had 14 tremors, two of which were of sufficient force to be felt by the public. The first, at 3.35pm, was of 3.6 on the Richter scale; the second was at 5.43pm, of 3.1. The remainder were all bewteen 1.5 and 2.7.

Update 8 October midnight: The Government has called for calm after a tremor registering 4.3 on the Richter scale occurred one kilometer to the south-east of El Pinar. The tremor, which occurred just after half past nine this evening, was felt throughout the island and is the strongest to date.

No private damage has been reported but rockfalls have blocked the Tacorón to La Restinga road. Rockfalls also occurred on the exterior sides of the Los Roquillos tunnel.

The Government reminded the public again to pay heed to official communications and follow any advice given. DA

Eventos_HIERRO_2011 (490 x 490)

Update 8 October: Since the last post El Hierro is still having at least tens of tremors a day; last night, for example, had 30, most around 2 on the Richter scale, but one being 3.2. The island’s main traffic tunnel remains closed, and of those evacuated some 20 or so have still been unable to return to their homes.

Update 29 September: IGN says that the latest tremor an hour ago (10.12am) was 3.8 on the Richter scale and was felt throughout the island.

Update 28 September: There are somewhat mixed messages coming out of El Hierro tonight. Most positively, the situation is said to have become stabilized, with the increase in frequency and intensity of the tremors last night having stopped for the moment. Schools will re-open tomorrow.

The Los Roquillos tunnel, however, which connects the capital, Valverde, with the El Golfo valley, will remain closed, causing some considerable disruption to the island’s traffic. Not the least affected will be traffic to the re-opened schools, with children from the Frontera municipality who go to school in Valverde having to travel via the peak.

Of the evacuations announced last evening, only 50 or so were actually deemed necessary in the event. These residents will remain in their temporary accommodations again tonight: the majority are staying with family elsewhere on El Hierro. The situation will be reviewed tomorrow and further decisions taken then on whether it is safe for them to return home.

Meanwhile, it seems from latest readings that the focal point for the tremors is moving towards the south of the island, and a military emergency team of 27 is being sent to El Hierro to collaborate with the island’s emergency council: 14 of the team are from Tenerife. Their placement is part of Pevolca’s civil protection and volcanic risk emergency plan, and they are envisaged as being under the direction of the El Hierro Cabildo, not least to help with possible evacuations and accommodations for displaced residents.

The general prognosis at present is little more, it seems to me, than an educated guess, albeit a highly educated one. What is being envisaged is an eruption, but not in the sense of a volcanic explosion. Rather, magma is foreseen as erupting through a fissure created by the magma’s own pressure. This, it is anticipated, would create a new volcanic cone … essentially the island is still young and growing.

The authorities and experts say this will be a “low-grade” and non-violent eruption, but all the same, they anticipate that El Hierro could give birth to a new mountain around 200 metres high. PV

Update 27 September: The Canarian Government is evacuating 300 people in the municipality of Frontera because of fears of rockfalls caused by seismic activity, and has also ordered the closure of the Los Roquillos tunnel from 11pm tonight until further notice. Also, the schools in the municipality have been ordered to shut.

The Government’s action is based on recommendations from the Instituto Geográfico Nacional (IGN) which forecasts increases in intensity and frequency in seismic activity from midnight tonight.

In terms of the evacuations, these will affect the Las Puntas, Sabinosa, Pie Risco, Pozo de la Salud, and Guinea areas, all in the municipality of Frontera.

The Government called for calm and reminded the public that the island is still on yellow alert, and that the seismic activity is what would be expected.

Given the expected increase in intensity and frequency of earthquakes, the public is asked to bear in mind the following recommendations :

If you are indoors during an earthquake:
• do not go outside until the movement has ended
• seek refuge under strong structures
• stay away from windows, internal walls, dressers, cabinets, and any objects that may fall
• stay out of the kitchen
• do not use lifts
• if the quake is a severe one, shut off light, water and gas supplies once it has finished

In a public building (supermarket, cinema, etc):
• don’t race for the exit
• keep away from windows or glass doors
• protect yourself under strong structures
• move from aisles in supermarkets or bookshops or the like, and crouch down at the end panels
• in schools, ensure children get under their desks and protect their head with a book or similar

If you experience an earthquake while outside:
• keep calm and try to encourage others to remain calm and not to panic
• make your way to open areas, keeping away from damaged buildings
• do not enter any damaged buildings
• if driving, stop safely, trying not to block the road. Turn on the radio to listen to any official broadcasts, recommendations and news about blocked roads

Information will be made available through the media, information centres, etc., and the wider public is asked to stay away from these areas because they will be dangerous, and they could interfere with important rescue work.

el hierro volcanic activity

Update 25 September: It’s 218 years since the last eruption on El Hierro, and although the alert is still “only” yellow, vulcanologists are talking of an eruption again. Involcan, which is the Instituto Volcanológico de Canarias, says that the risk is small, but significant.

volcanesdecanarias.com has the above graphic of what might be going on under the surface of El Hierro at present.

Eventos_HIERRO_2011 (490 x 490)

Original post 24 September: The Canaries’ westernmost island, El Hierro, has been having earthquakes for months now, so small that the vast majority can’t actually be felt, but there has also been an increasing concern that something must be happening to explain the thousands upon thousands of tremors and the sudden rush of seismic activity. As the above graphic from the Spanish National Geographic Institute shows, there have been 7,920 such “events” since 19 July this year.

For months, too, the authorities have been trying to play it cool, but within the last fortnight, the activity increased and spread. Still the El Hierro Cabildo said that there was a security and emergency plan in place which, in the worst event, foresaw the evacuation of all the affected zones, and that the public should remain calm. The Cabildo gave assurances that there was no cause for concern even though it admitted that the latest seismic activity was not normal.

As of yesterday, however, the Canarian Government has issued a first stage (yellow) alert for the situation on El Hierro. The decision was based on the conclusions of a meeting yesterday morning of the Scientific Plan Committee, which has reported on changes in seismic energy and “deformations”. This “yellow” phase is said to be a “volcanic risk pre-emergency”, and consists of the provision of increased official information and protective measures in case of eruption, still said not to be very probable.

The pre-emergency phase requires the public to be prepared for an unfavourable evolution of seismic activity, and to pay attention to official prevention and protection messages from the authorities. The general measures required are the following:

• Listen to official reports about volcanic activity and its development on the radio or TV. Ensure there are sufficient batteries for the radio.

• For any additional clarification call 012

• There are also pages available on the Canarian Government and El Hierro Cabildo websites.

• Ensure that all important personal documents are collected together to be able to remove them in an emergency.

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