quote: Op woensdag 2 november 2011 23:22 schreef Takkembah het volgende:Weet iemand wat teideano nu op Twitter roept? Tis spaans en zit op toon dus kennie vertalen.....
quote:Overview update 03/11 09:07 UTC :A further climb in harmonic tremor since a number of minutes. The frequency of the tremor has hardly changed since many days. A sharp change in frequency (the colors in the lower part of the graph) will probably coincide with a new event (not necessarily a new vent).Overview update 03/11 08:47UTC :In an attempt to give a better view on what we are describing about harmonic tremor in many updates below, we have assembled the data of the last 3 days.** FYI Wikipedia description of Harmonic tremor : Harmonic tremor describes a long-duration release of seismic energy, with distinct spectral (harmonic) lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor is a sustained signal that may or may not possess these harmonic spectral features. A harmonic tremor is a sustained release of seismic and/or infrasonic energy typically associated with the underground movement of magma and/or venting of volcanic gases from magma. Being a long-duration continuous signal from a temporally extended source, a volcanic tremor contrasts distinctly with transient sources of seismic radiation, such as tremors that are typically associated with earthquake and explosion.**3 days harmonic tremor assembled - all data courtesy IGN - Click on the image to watch the bigger size imageOverview update 03/11 08:12UTC :- Pevolca has announced yesterday evening that based on yesterdays data, they could not conclude that an eruption is imminent.- Increasing harmonic tremor and a turbulent seismogram are contradicting the words of Pevolca. The IGN scientists at Pevolca have however a lot more data than published on the IGN website. (see below)- Some of the more experienced amateur volcano followers ( Iceland volcanoes) @ jonfr.com have other opinions, although they admit that not having all the data is a problem to have a truly good view on the situation. The discussions go often very deep and tend to become very technical.- One of the problems for scientists is that the past Surtseynian eruptions like the ones that happened in Iceland and in the Azores, are not as documented as eruptions are today, which make comparisons rather difficult.- Earthquake-report.com wants to thank the many readers who are writing us with tips, local contact persons, etc. This help is not only appreciated but essential to verify upcoming events.- IGN has listed 19 earthquakes since midnight, the strongest one being a 2.7 to the West of Frontera. The depth varies in between 12 km and 22.10 km. Nothing special one would say, but harmonic tremor is indicating constant magma stress below the volcano.
quote:The pyroclastic de La Restinga are composed of basalt and trachyte with no chemical reactionCSIC representatives as part of the scientific committee of the Civil Protection Plan for Volcanic Risk (PEVOLCA) have moved into the direction of the Plan, the preliminary results on the first pyroclastic thrown to the surface of the Sea of calms. The fragments are formed by a magma mixing between two materials, one black (basalt) and one white (trachyte), which occurred at the time of the eruption so it is a physical mixture between the two materials without the two chemical reaction has occurred.In this regard it is noteworthy that these trachytes are volumetrically insignificant and constitute more than an anecdote that the main feature of the eruption. In reality the samples have been collected along these days, the trachyte was only present in the first few episodes as a ratio of 1 to 10 with respect to the basalt, which does not involved in determining the type of resulting eruption.Its origin may be due to a Remobilization (reflow) of a small remnant of material from the basalt trachyte again on his way to the surface. These processes are not so rare in this type of volcanism occur in a short time (a few hours to few days).These results, although they had already been advanced, had not been made public because it had not yet completed the series of tests to do in this type of study, and not relevant to consider that the presence of magma mixing as driver dynamics of the eruption.It should be noted that studies have been published in the media today during a concern is for staff responsible for its production and not a formal request from the City of El Pinar, as he said.To avoid confusion arising from contradictory information, especially the residents of El Hierro, the direction of PEVOLCA stresses the importance of following the official statements that leads to the population. To this end and for those scientific and research institutions wishing to participate in the study of eruptive phenomenon, the Canary Islands government has created a Scientific Steering Committee, to achieve effective coordination and discussion of research in order to a better guidance to bodies responsible for Civil Protection.PROCEDURESFrom the first moment CSIC members took charge of the pyroclastic sampling and its analysis following the usual procedure in these cases, ie the samples sent to different laboratories to compare results and to have a spectrum the broadest possible range of data. Some of the samples were sent to Madrid (MNCN, CSIC), Barcelona (ICTJA, CSIC) and the University of Huelva, where they are doing experimental petrology studies to determine the thermodynamic characteristics of eruptive magmas. In addition, samples have also been sent to Washington State University, in the United States and of Clermont Ferrand, France, for isotopic analysis.Basalt and trachytesBasalt is the most common magma eruptions of El Hierro, has a 43 percent SiO 2, reaches a temperature of 1,200 ° C and a density of 2700 kg/m3.The trachyte is a magma with a SiO2 content of 63%, reaches a temperature of 850 ° C and a density of 2,300 kg/m3. The trachyte is not the predominant magma erupted, therefore does not contribute to increase the explosiveness of it.Both the basaltic material as the trachyte samples are highly vesicular, which means that both had a high amount of gas in the time of eruption, which would explain why it is explosive (pyroclastic formation) despite the sea water pressure on the mouth of issue. However, this type of explosive is normal within the parameters of basaltic eruptions with which we move and no additional hazard is of the fact also contain trachytic magma.
quote:NOTE AVCAN 299 - EARTHQUAKE ACTIVITY-VOLCANIC -El Hierro ISLAND - 03 November 2011-12:00h - peninsular - Seismic activity remains high, with moderate seismicity in the El Golfo region in terms of number of earthquakes and their magnitude and with a signal tremor through the roof, noticing especially in Restinga area, saturating the sensor and prior to the first eruption, but more unstable and numerous explosions. The magnitude of the earthquakes between 4.4 and 1.4. New earthquakes 41. Earthquakes senses 2. Depths between 16 and 22km (and two to 15 and 15km and two at 24 and 25 km). The day before yesterday 69. Yesterday 101. Now go 22. A total of 11,022 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).
quote:The tremor is triggered, indicating the nearby opening of a new mouth or eruption, that's the first thing we see today, so please you are in alert and aware of warnings can be issued. Also have been a number of earthquakes, particularly the following from the last part. If you have any sense, do not forget to fill in the questionnaire IGN (Enrique):
quote:Evolution of the stain and photos of the Civil Guard helicopter seems to have taken this morning in front of the Restinga and furnished to EFE that can be seen daily in the province and where the point seems to be eruptive. (Enrique).
quote:bronAccording to the latest PEVOLCA statement: "The scientific committee spokesman Civil Protection Plan for Volcanic Risk (Pevolca), Carmen Lopez, said that Border seismic events, which have intensified in recent days ... correspond to the stage of La Restinga underwater eruption, which began on 10 October.Lopez noted that the high seismicity that has occurred with magnitudes of 4.3 and 4.4. has affected the feedback mechanism of the process magmatic eruption of La Restinga, "generating a process of 'rectified diffusion', an injection of magma pressure in the emission rate increases and releases large amount of gas."This phenomenon is what has been represented in discrete pulses of tremor and new spots appeared on the surface of the Mer de las Calmas, which turn white, brown along the pyroclastic material, precisely because of the presence of gases .However, scientists do not completely rule out that another seismic "smaller and smaller scale" that is occurring at 15 kilometers deep in Earth's crust in the area of El Golfo, could result in a submarine eruption, but not imminently. "However, in this interview with a scientist aboard the Margalef said that there are cracks in El Golfo and is observed on the rocky bottom sediments new generation of them. Full saying there's a new fracture and is out some material in suspension.Encuentran fisuras en el norte de la isla por donde sale material------------------In the graph of the evolution of seismic energy by half every 6 hours and a half deep, you can see the evolution before the eruption of the first swarm to the eruption, then the system is no longer representative to start with disperse seismicity and volcanic system reactivated with this second swarm holding at the same depth from day 20 to 22 October when the intrusion began, staying between 20 and 22 km, with some forays to shallower areas about 17 km, but the latter must increase days the area of activity is unstable and fluctuates more.In principle one might think that we need more activity in the northern shallow ahead of a possible eruption, although tremor signal so that small earthquakes are not detected, may not see ... although I think there will be shallow earthquakes before the possible eruption of the northern zone (Enrique).-----------------------------In the graph of evolution of the depths of the earthquakes from October 1, you can see the activity of the pine forest before and after the eruption. You can also see how the second swarm activity centered in the Gulf was concentrated until five days in two horizontal zones or sills between 19 and 23 km and a shallower between 16 and 17 km, taken as the last days are merging as one area, indicating that whatever is coming up from below, but has not yet come up. (Enrique)
quote:Update 03/11 23:45 UTC :Earthquakes are getting stronger again. Just recently at 23:06 a quake at 22 km depth measuring M 3.2 occurred NW of Frontera (the first one today above 3).Update 03/11 22:53 UTC :The pictures below are courtesy of the Presidencia del Gobierno de CanariasThese pictures have been taken out of a helicopter and are showing the November 3 jacuzzi (burbuja in Spanish). No green stain today but the grey muddy color is present. It looks to us that the new spot is at a bigger distance from the coast. Click on the pictures to see them at full size images courtesy Presidencia del Gobierno de Canariasbron
quote:New October 31 RapidEye satellite pictureWhat do we see new on this partly too cloudy image.- the light green stains are far bigger than seen previously as dark green stains on the Guardia Civil pictures (the dark green stains on the RapidEye pictures are shadows of the clouds).- the grey muddy eruption vent activity was not seen anymore on October 31 (Raymond looks to be wrong here as he stated that the venting continued all the way)- that the current to the right of La Restinga blocks the stain from being spreading to La Estaca- a big mystery is the coloring in the El Golfo bay. was this coloring created by the sea currents or by new activity- the dark green patches can also be seen in the El Golfo area (see comment about colors above)!- why not asking IGN or CSIC scientists to explain what we see on the images, which we repeat, are far better than anything else we have seen so far.The images have not been ordered by the Spanish state or anybody else, but are an initiative of RapidEye themselves. The least Spanish scientists can do is sending a thank You message to the RapidEye management.Click on the picture to see the full imageOverview Update 04/11 08:31 UTC :- 16 + M1.5 earthquakes since midnight, 15 were greater than 2 and 10 were greater than 2.5.- based on the data above, it looks that the seismic activity will further increase today. We expect that we will have multiple +3 quakes during the rest of the day.- we are not sure at all, but it looks that the new Jacuzzi location is different from the October 10 one. If this would be true then the place of the current eruption will have another depth. We hope that the scientists will publish a report with the exact location parameters and/or depth of the new vent (if new) so far we havent seen them- Joke barometer says all quiet in the village if someting new did happen, she sees it immediately as people behave more nervous and start discussing the subject
quote:Border seismic events are the scene of the submarine eruption of La RestingaThe direction of PEVOLCA remember that there is risk to the public but all civil protection resources are activatedFrontera seismic events, which have intensified in recent days, corresponding to the scene of the submarine eruption of La Restinga, which began on 10 October. This has been reported Carmen Lopez, spokesman for the scientific committee of the Civil Protection Plan for Volcanic Risk (PEVOLCA) after the meeting of the Steering Committee. Lopez noted that the high seismicity that has occurred with magnitudes of 4.3 and 4.4. has affected the feedback mechanism of the process magmatic eruption of La Restinga, "generating a process of 'rectified diffusion', an injection of magma pressure in the emission rate increases and releases large amount of gas." This phenomenon is what has been represented in discrete pulses of tremor and new spots appeared on the surface of the Sea Calm, which turn white, brown along the pyroclastic material, precisely because of the presence of gases . However, scientists do not completely rule out that another seismic "smaller and smaller scale" that is occurring at 15 kilometers deep in Earth's crust in the area of the Gulf, could result in a submarine eruption, but not imminently. This eruption would be similar to the South, but given much more depth of ocean floor bathymetry in the area. In any case, it would be necessary to give other values that "at this time do not exist." Note that in this day the ground deformation has stabilized in the North, which had experienced some acceleration in recent days and is significantly relaxed in the south. To this is added the decrease of the seismicity and the stabilization of the tremor signal. Lopez wanted to point out that historically, in the Canaries, "no two eruptions have occurred simultaneously." Despite the alarming situation has created this situation for the population, the Director General of Security and Emergency of the Canary Islands, Juan Manuel Santana, stressed "the eruption of the South no risk for the population" and insisted that Scientists are monitoring for 24 hours, at the slightest variation of the current trend "must preactivated all civil protection resources."
quote:NOTE AVCAN 301 - EARTHQUAKE ACTIVITY-VOLCANIC - HIERRO ISLAND - 04 November 2011-11:30 h peninsular - Seismic activity remains moderate to high, with seismicity is moderate in the El Golfo area (all over 2.0 less than an earthquake) and signal with a very high volcanic tremor since yesterday and is still increasing in the last hours, noticing especially in Restinga area, saturating the sensor and unstable behavior and numerous explosions. The magnitude of the earthquakes between 3.2 and 1.9. New earthquakes 24. Earthquakes senses 2. Depths between 17 and 23km (and one at 15km). The day before yesterday 101. Yesterday 101. Now go 17. A total of 11,056 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).------------------Transit seismicity, since the beginning of the crisis, not traditionally present day, but by event. Each seismic event, in terms of their energy release and position change the route followed by a supposed "seismic center of gravity" would be found under the Tanganasoga now. This chart takes much computational time because each point is the result of comparing every event against everyone else that has been. (JR)Foto
quote:Update 04/11 10:51 UTC :An helicopter is currently flying above La Restinga and the Las Calmas Sea. Let us hope that he is shooting images and video.
quote:Update 04/11 11:19 UTC :Pevolca will call a meeting in La Restinga at 18:00 local time to inform the villagers about all current activity.Rapideye foto's van 26 en 31 okt.
quote:El Hierro May Have New Volcanic VentPEVOLVA and the National Geographic Institute (IGN) have announced how El Hierro has recorded a total of 24 Earthquakes since midnight and 11.00 hrs CET this morning, averaging around 3.0 on the richer scale.The highest was measured off the North-West of the Island at 3.2 less than 1 hours ago, with the remainder measuring from 1.9 to 3.0, with ten of the quakes measuring over 2.5.The depths of the activities were around 22km.Observers have noted the high number of earthquakes with a stronger magnitude and expect that this will continue throughout Friday.Meanwhile, to the south of the island and off the coast of La Restinga, Scientists have noted a change in the colour of the stain and bubble formations rising to the surface as a result of the volcanic eruption, and are looking into the possibility of a further vent now becoming active.A helicopter is currently flying above the eruption zone in order to gather further information for analysis.
quote:'We hope the volcano does not explode'MEDINA MOROTE CIRA explosive or harmless, that is the question. The apparent discrepancy between the data provided by the Pevolca and professor at the University of Barcelona Sunday Gimeno on the dangers of magma of El Hierro had yesterday its second chapter. "Hopefully they do not disprove the volcano with a large explosive eruption," the Catalan researcher, who told this newspaper that, contrary to what CSIC scientists argue, "most of the rhyolite pyroclastics are volumetrically" that is, one of the most explosive magmatic material existence. Of course, if someone has had access to the volcano's pyroclastic at mar de Las Calmas, these have been the CSIC volcanologists Joan Martí and Ramon Ortiz, who have been integrated into the Pevolca from the beginning. On Wednesday, Gimeno gave the bell with his explosive conclusions. In his report was clear that the City of El Pinar which requested the chemical analysis of samples was done for free, "because it is a sample collected in the context of national emergency", and the University of Barcelona is a public body. It also describes all the techniques that were used to obtain the data and the time elapsed since the arrival of materials, October 27, until they could make findings, only two days later. The question that the scientist is why, if so immediate analysis, the public did Pevolca their data until Wednesday, coinciding for his appearance in the media. The fact that the analyzed material containing rhyolite gives a special explosive power, which has been consistently dismissed by experts Pevolca. But that is not all. "The presence of pyroclastic material in the differential is significant, regardless of the genetic interpretation to be given, provides clear indications of a much larger explosive potential, so far not publicly mentioned by anyone, as we have been monitoring the news in press, radio and national television, "says petrologist in the report. He continued: "The inhomogeneous mixing of different magma compositions is a phenomenon widely reported in the literature as increasing the explosiveness of a magma, and on many occasions as a trigger for an eruption." The point is that, at all times, there has been talk of an eruption surtseyana, quiet apart from the time the magma hits the surface, when a column of steam, followed a few hours, an ash , the famous rooster comb, which has given much play. Well, not always according to Gimeno. "The test material does not exhibit the characteristics of a surtseyano like rash, which is the stage repeatedly proposed by the scientific monitoring committee, at least for more than a week in the first phase of the eruption," he says. Professor at the University of Barcelona can not escape to devote the final paragraph of his report to the manner in which the crisis is being managed El Hierro. "We must make the effort to attract talent, first local and national environment closer, prioritizing the description and understanding of personal hypotheses or small groups. Since it is also obvious, urgent works are used public funds and is played with the safety of persons and property ".
quote:Apparently, the PEVOLCA will meet this afternoon at 18:00 hours with the residents of La Restinga and tomorrow at the same time do so in the Llanillos. Some reports suggest that these meetings could be direct between scientists and residents, that is, without the mediation of political representatives. From AVCAN propose, if it seems appropriate that we discuss what questions they would like to ask members if they had that opportunity PEVOLCA. Perhaps that helps for some of the people attending. Please ask questions that proposed are concise and aimed at clarifying the situation. It is an opportunity for residents, so they can answer your questions, so we understand that there is no room for criticism, insults and speculation. Thank you for your cooperation. (Fernando)Bron
quote:The volcano is smoking again and ejecting pyroclasticsThe submarine volcano has returned to La Restinga morning drive to smoking pirclastos sea surface, as confirmed by sources on a daily face IRON. There are many residents who have contacted this newspaper to inform us that plumes observed in sea surface product of the expulsion of this material.DIARIOELHIERRO.ES, writing (04.11.2011. 11:50 am)The submarine volcano has returned to La Restinga expel pirclastos smoldering this morning to the sea surface, as confirmed by sources on a daily face Hierro. There are many residents who have contacted this newspaper to inform us of the smoke observed sea surface.For its part, the scientific committee spokesman Civil Protection Plan for Volcanic Risk (Pevolca), Carmen Lopez, said yesterday that seismic phenomena Frontera, which have intensified in recent days, correspond to the scene of underwater eruption La Restinga, which began on 10 October.Lopez noted that the high seismicity that has occurred with magnitudes of 4.3 and 4.4. has affected the feedback mechanism of the process magmatic eruption of La Restinga, "generating a process of 'rectified diffusion', an injection of magma pressure in the emission rate increases and releases large amount of gas."This phenomenon is what has been represented in discrete pulses of tremor and new spots appeared on the surface of mer de las Calmas, which turn white, brown along the pyroclastic material, precisely because of the presence of gases .
quote:The most remarkable increase in tremor in my view, implies an increased flow of magma, which produces cavitation induced vibration is observed in both seismographs, as part of the population of the Restinga. Where magma is leading this ....? The submarine volcano Restinga of course, but ... Have you opened any new mouth submarine that allows pressure relief magma? May it be so. (JR)[bron]
quote:The tremor of the Restinga in the south is increasing in amplitude from this morning to saturate the sensor signal, but still fails to completely saturate the sensor as it did in early October. The seismicity in El Golfo north indicates that the volcanic system is pressurized, the 3.8 of a while ago, is a mark that will continue until the seismicity depressurize or lose strength.In principle it shows activity in the mer Las Calmas, fissure type, but not a big mouth is defined to allow a drop of clear tremor, so I think it will continue opening mouths, and increasing the road , is still closer to the coast, so there will be very aware if a mouth opened near the coast and / or land to be very alert to official information they can get on the evolution of the phenomenon (Enrique)Link
quote: Op zaterdag 5 november 2011 07:21 schreef Takkembah het volgende:Nog een 3.3 om 00.11 geweest
quote:The direction of the Civil Protection Plan for Volcanic Risk (Pevolca) decided last night to close the access road tunnels Roquille until 07:30 in the morning as a preventive measure before the earthquake of intensity 4.4 on the scale Richter took place at 20:36 hours in Frontera and the possibility that it could raise that amount, according to warnings from the National Geographic Institute (IGN). The opening of the tunnel in the morning was expected to surveillance and security measures.It has also carried out the eviction of the 11 houses of the points that were more likely to be affected by landslides.These preventive measures are discussed in separate morning meetings of the scientific committee and steering committee to assess maintenance or making other decisions that may be necessary depending on the situation.EARTHQUAKEThe Emergency Coordination Center and Security (CECOES) 1-1-2, under the Ministry of Economy, Finance and Security of the Canary Islands, received between 20:37 and 21:28 yesterday evening, 45 calls by inhabitants of the three municipalities of El Hierro and related to the earthquake that occurred this evening on the coast of the islandAlso in that same time slot, the CECOES attended some calls from the municipalities of Arafa and Santiago del Teide, both located in the south of Tenerife, and Valle Gran Rey in La Gomera.The most important incidents connected with this phenomenon have been associated with some detachments located in the heart of Sabina and in the area of Guinea, without consequences.In this sense, IGN has confirmed to the direction of Pevolca that there was an earthquake of magnitude 4.4, the western border, with a depth of 21 kilometers.
quote:NOTE AVCAN 303 - EARTHQUAKE ACTIVITY-VOLCANIC - El HIERRO ISLAND - 05 November 2011-11:30 h peninsular - Seismic activity remains high, with seismicity is moderate in El Golfo area and volcanic tremor signal in the area of La Restinga that after a decline yesterday, has gone up saturating the sensor and unstable behavior and numerous explosions. The magnitude of the earthquakes between 3.9 and 1.9. New earthquakes 20. Felt earthquakes 3. Depths between 17 and 21km (and one at 11km and another 25km). The day before yesterday 39. Yesterday 37. Now go 14. A total of 11,091 earthquakes are located in El Hierro by IGN from 9:00 am of July 19, 2011 (Enrique).[bron]
quote:The volcano of El Hierro loose slag by several cratersResearchers aboard the research vessel 'Ramon Margalef' studying whether it has opened a new mouth in the north of the island after finding "new generation materials" and gas leaks in El Golfo.The volcano has been living for three weeks with the residents of El Hierro is more awake than ever. So much so that in their eagerness to be noticed has opened several mouths to keep throwing the slag as it is called the material released in the Atlantic with an eruption.A helicopter ride over mer de las Calmas allowed scientists to monitor the evolution of the volcano certify the existence of a string of craters could be three open in a straight line quite well defined. A row of gas bubbling and steaming pyroclastic would correspond with the fracture of the crust, more open than ever, which Hierro volcano unleashes its power.By releasing tensions that crack, the technicians of the National Geographic Institute (IGN) observed a "significant" decrease in the number of earthquakes that shook the north of the island because of the volcanic magma bustle output below El Hierrro.Thus, only 39 earthquakes recorded IGN on Thursday a sense by the public and the press time numbered only 26 in the day yesterday, on an island used to half a hundred earthquakes a day. Of course, a magnitude 3.8 earthquake with an epicenter located just five miles from Frontera represented the only shock to the northern population, while in the south watching the bubbling volcano, closer than ever to La Restinga.The question of a crack in the northTo these concerns was added a doubt, the possibility that a small crack had opened in el Golfo, against Frontera, suggested by the current head of the research vessel campaign Ramon Margalef, Eugenio Freire. Apparently, last Thursday observed some release of materials at those seabed, but the ship had to return to port of Los Cristianos on Tenerife Island to refuel and take on board new teams of researchers.Yesterday, the Ramon Margalef returned to the waters of El Hierro to verify this impression, which officials said could not be confirmed. Freire had claimed that "there are sediments new generation" on the ocean floor: "There are some cracks and some stuff is coming," said lead researcher of the Spanish Institute of Oceanography (IEO) was quoted by Antena 3 Canarias. Freire is the third campaign chief scientist Ramon Margalef eruption on the phenomenon of El Hierro, whose mission is to analyze the physico-chemical state of the waters. The vessel's presence will help clarify the situation, as when doubts arose about whether he had in front of La Restinga eruption at first.The head of the first campaign, the IEO researcher Juan Acosta, who was in charge of studying in detail the geology of the seabed islanders, last week also noted an anomaly in these soils, "small gas leaks very fine" that could be of "volcanic or biological." He described the terrain in that area contains an old scar the result of an underwater landslide.Yesterday, the priority of the authorities was to the south, La Restinga, where they held a meeting with residents on Thursday after some of them leave their homes in fear. The scientific spokesman of the crisis committee, María José Blanco, said that there is a single eruption in progress, but fissure type being the material always comes out the same place. In addition, the researcher explained that the volcano IGN maintains an "irregular emission rate" marked by seismicity that occurs in the north of the island.