É de facto excelente... esta crise sísmica em La Palma está a preocupar as autoridades.
Actividade Vulcânica 2018
- Thread starter luismeteo3
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Meteogramas MeteoPT: Capitais de Distrito/Açores/Madeira | Coordenadas
Seguimento Meteorológico: Litoral Norte | Interior Norte e Centro | Litoral Centro | Sul | Açores e Madeira | Livre Previsões: Curto e médio prazo: até 2 semanas | Longo prazo: mensal e sazonal (Regras e links úteis nos 1ºs posts)
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Quase 900 sismos até agora com um sismo de M4.1 a pouco... http://en.vedur.is/earthquakes-and-volcanism/earthquakes/tjornes-large/#view=map
Earthquake swarm under Cumbre Vieja volcano, Canary Islands
National Geographic Institute (IGN) registered a total of 83 earthquakes between 23:23 UTC, February 10 and 07:32 UTC, February 15 with magnitudes ranging from 1.6 to 2.6.
In addition, there have been several hundred more which weren't detected due to their magnitude and depth.
The depth of the quakes decreased during the course of the swarm, suggesting an upward movement of magma towards the surface.
The 47-km-long (29 miles) wedge-shaped island of La Palma, the NW-most of the Canary Islands, is composed of two large volcanic centers. The younger Cumbre Vieja, the southern volcano, is one of the most active in the Canaries.
https://watchers.news/2018/02/16/earthquake-swarm-under-cumbre-vieja-volcano-canary-islands/
National Geographic Institute (IGN) registered a total of 83 earthquakes between 23:23 UTC, February 10 and 07:32 UTC, February 15 with magnitudes ranging from 1.6 to 2.6.
In addition, there have been several hundred more which weren't detected due to their magnitude and depth.
The depth of the quakes decreased during the course of the swarm, suggesting an upward movement of magma towards the surface.
The 47-km-long (29 miles) wedge-shaped island of La Palma, the NW-most of the Canary Islands, is composed of two large volcanic centers. The younger Cumbre Vieja, the southern volcano, is one of the most active in the Canaries.
https://watchers.news/2018/02/16/earthquake-swarm-under-cumbre-vieja-volcano-canary-islands/
What is happening to Grímsey?
Over the past few days and weeks has passed a huge earthquake storm near east of Grímsey. This is a very well-known earthquake area, which is part of the discord of Iceland. The signposts in the north of Iceland are from Vatnajökull and north of Öxarfjörður, from which they shift through a northwestern direction into the Kolbeinsey Ridge, north of Grímsey. This shift is obscure by some volcanic erosion, each of which has a northern direction. The last known volcanic eruption in the area became close to the Mánárey river in 1867. The high-temperature area on the seabed is also known in these areas, but the high-temperature systems are associated with geological young volcanic activity.
In recent years, ÍSOR has worked on a database of depth measurements and very accurate maps of the seabed on the Icelandic continent with support from the European Union Research Funds. Geologists Ögmundur Erlendsson and Árni Hjartarson have done this work. For the work, ÍSOR has received a lot of data from various sources that have measured the ocean floor for various purposes in recent years. The depth measurement base of ÍSOR consists of data from the Coast Guard's Marine Metrology Department, Marine Research Institute, Orkustofnun, University of Iceland, OLEX and several international research pipelines.
Depth of the seabed from the north of Iceland. Deep depths of the seabed from the North. The blue dots represent places of known volcanic eruptions from historical times, other than Mánáreyjar from Tjörnes in 1867 and the other north of Grímsey in 1372.
The volcano systems where the plate and the gosbelt shift from Öxarfjordur north to Kolbeinseyjar Ridge.
This picture shows the volcano systems as the plate and the gosbelt shift from Öxarfjordur north to Kolbeinsey Ridge. The southeast coast is the Mánáreyja volcanic system, after which Nafir reaches the northernmost Grimsey, then the Hóll and finally the Stóragrunnur volcanic system.
The volcanic system Nafir north of Grímsey. The figure shows further the volcanic system that is taught at Nafir Northeast Grímsey. It is delimited with a red line. Note that the north is to the right of the picture and the outlines of the Grímsey Islands are shown on the black surface high in the picture. In the Nafas area there are some volcanoes that rise considerably high above the seabed and some of them are visible at the top marked with blue deplum. The main fractures and faults on the seabed are marked with black bars.
The Icelandic Meteorological Office operates a terrestrial satellite earthquake (SIL) system. The data is open and accessible. However, it should be noted that the data displayed shows a tremendous amount of tremor activity, and a more thorough processing would require the data to provide a finer trigger in the tremor function. In general, the depth determination of an earthquake is somewhat uncertain unless the measurement station is close to the source of the earthquake. Another thing that inhibits the exact location and analysis of tremors in the Grímsey area is that meters are almost only south of the tremor uptake, but it would be best to have a telescopic meter all round. However, the measuring station in Grímsey is quite close to the source, which is a benefit for depth determination.
Below are two pictures that are processed at speed from the Meteorological Database. This is done with great care of possible errors, but should give a fairly clear picture of how the tremors spread.
Images from the Icelandic Meteorological Database are showing the distribution of an earthquake.
Depth of depth through the area of the earthquake.
The upper image shows the east-west and north-south depths through the origin of the earthquakes, showing that they are in a very limited area from the surface down to a depth of 15 km. The bottom shows the size of an earthquake with depth. The vastest earthquakes are below 5-7 km of depth.
Finally, here's a picture where the earthquakes are displayed at the exact depth map.
Earthquakes at Grímsey are at a depth of depth. The figure shows that the thunder of the earthquake is about 10-12 km east of Grímsey, below and near the southernmost subterranean mountain in the volcano system called Nafir. This indicates some kind of stirring associated magnetic motions in the crust under the volcano. It should be noted, however, that no gosorium has detected an earthquake meter when written. It is also the experience to teach us that fire fractures with magnetic movements in the crust do not necessarily lead to an eruption. A good example of this is the dynamics of the evolution for several years.
Posted February 16, 2018
Ólafur G. Flóvenz, Ögmundur Erlendsson, Egill Árni Guðnason.
http://isor.is/frettir/hvad-er-ad-gerast-vid-grimsey
Over the past few days and weeks has passed a huge earthquake storm near east of Grímsey. This is a very well-known earthquake area, which is part of the discord of Iceland. The signposts in the north of Iceland are from Vatnajökull and north of Öxarfjörður, from which they shift through a northwestern direction into the Kolbeinsey Ridge, north of Grímsey. This shift is obscure by some volcanic erosion, each of which has a northern direction. The last known volcanic eruption in the area became close to the Mánárey river in 1867. The high-temperature area on the seabed is also known in these areas, but the high-temperature systems are associated with geological young volcanic activity.
In recent years, ÍSOR has worked on a database of depth measurements and very accurate maps of the seabed on the Icelandic continent with support from the European Union Research Funds. Geologists Ögmundur Erlendsson and Árni Hjartarson have done this work. For the work, ÍSOR has received a lot of data from various sources that have measured the ocean floor for various purposes in recent years. The depth measurement base of ÍSOR consists of data from the Coast Guard's Marine Metrology Department, Marine Research Institute, Orkustofnun, University of Iceland, OLEX and several international research pipelines.
Depth of the seabed from the north of Iceland. Deep depths of the seabed from the North. The blue dots represent places of known volcanic eruptions from historical times, other than Mánáreyjar from Tjörnes in 1867 and the other north of Grímsey in 1372.
The volcano systems where the plate and the gosbelt shift from Öxarfjordur north to Kolbeinseyjar Ridge.
This picture shows the volcano systems as the plate and the gosbelt shift from Öxarfjordur north to Kolbeinsey Ridge. The southeast coast is the Mánáreyja volcanic system, after which Nafir reaches the northernmost Grimsey, then the Hóll and finally the Stóragrunnur volcanic system.
The volcanic system Nafir north of Grímsey. The figure shows further the volcanic system that is taught at Nafir Northeast Grímsey. It is delimited with a red line. Note that the north is to the right of the picture and the outlines of the Grímsey Islands are shown on the black surface high in the picture. In the Nafas area there are some volcanoes that rise considerably high above the seabed and some of them are visible at the top marked with blue deplum. The main fractures and faults on the seabed are marked with black bars.
The Icelandic Meteorological Office operates a terrestrial satellite earthquake (SIL) system. The data is open and accessible. However, it should be noted that the data displayed shows a tremendous amount of tremor activity, and a more thorough processing would require the data to provide a finer trigger in the tremor function. In general, the depth determination of an earthquake is somewhat uncertain unless the measurement station is close to the source of the earthquake. Another thing that inhibits the exact location and analysis of tremors in the Grímsey area is that meters are almost only south of the tremor uptake, but it would be best to have a telescopic meter all round. However, the measuring station in Grímsey is quite close to the source, which is a benefit for depth determination.
Below are two pictures that are processed at speed from the Meteorological Database. This is done with great care of possible errors, but should give a fairly clear picture of how the tremors spread.
Images from the Icelandic Meteorological Database are showing the distribution of an earthquake.
Depth of depth through the area of the earthquake.
The upper image shows the east-west and north-south depths through the origin of the earthquakes, showing that they are in a very limited area from the surface down to a depth of 15 km. The bottom shows the size of an earthquake with depth. The vastest earthquakes are below 5-7 km of depth.
Finally, here's a picture where the earthquakes are displayed at the exact depth map.
Earthquakes at Grímsey are at a depth of depth. The figure shows that the thunder of the earthquake is about 10-12 km east of Grímsey, below and near the southernmost subterranean mountain in the volcano system called Nafir. This indicates some kind of stirring associated magnetic motions in the crust under the volcano. It should be noted, however, that no gosorium has detected an earthquake meter when written. It is also the experience to teach us that fire fractures with magnetic movements in the crust do not necessarily lead to an eruption. A good example of this is the dynamics of the evolution for several years.
Posted February 16, 2018
Ólafur G. Flóvenz, Ögmundur Erlendsson, Egill Árni Guðnason.
http://isor.is/frettir/hvad-er-ad-gerast-vid-grimsey
Tjörnes Fracture Zone (TFZ) earthquake update at 13:20 UTC on 17-February-2018
Posted on February 17, 2018 by Jón Frímann
Information in this article are going to go outdated quickly.
As of the writing of this article total of 1593 earthquakes have happened in last 48 hours in Tjörnes Fracture Zone (TFZ). The reason for this earthquake swarm remains unclear at the moment. It is not clear if this is just tectonic earthquakes or have their origins in magma movements.
The earthquake swarm in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Met Office.
This earthquake swarm is dense. Copyright of this image belongs to Icelandic Met Office.
Largest earthquake since midnight has the magnitude of 3,7 so far. In the last 48 hours total of 27 earthquakes larger than magnitude 3,0 have happened east of Grímsey island. This earthquake swarm is happening in a volcano named Nafir (no GVP profile) and that volcano doesn’t have any documented eruption during the last 12.000 years that I know of (I might be wrong). It remains unclear at the moment if an eruption is going to happen at this location. At the moment there are no clear signs of magma movement, but ISOR (Icelandic article here) suggests that current earthquake swarm might be connected to magma movement in the area. If that is going to result in a eruption remains unclear in ISOR view.
I’ll update this article as needed today.
http://www.jonfr.com/volcano/?p=7355
Posted on February 17, 2018 by Jón Frímann
Information in this article are going to go outdated quickly.
As of the writing of this article total of 1593 earthquakes have happened in last 48 hours in Tjörnes Fracture Zone (TFZ). The reason for this earthquake swarm remains unclear at the moment. It is not clear if this is just tectonic earthquakes or have their origins in magma movements.
The earthquake swarm in Tjörnes Fracture Zone. Copyright of this image belongs to Icelandic Met Office.
This earthquake swarm is dense. Copyright of this image belongs to Icelandic Met Office.
Largest earthquake since midnight has the magnitude of 3,7 so far. In the last 48 hours total of 27 earthquakes larger than magnitude 3,0 have happened east of Grímsey island. This earthquake swarm is happening in a volcano named Nafir (no GVP profile) and that volcano doesn’t have any documented eruption during the last 12.000 years that I know of (I might be wrong). It remains unclear at the moment if an eruption is going to happen at this location. At the moment there are no clear signs of magma movement, but ISOR (Icelandic article here) suggests that current earthquake swarm might be connected to magma movement in the area. If that is going to result in a eruption remains unclear in ISOR view.
I’ll update this article as needed today.
http://www.jonfr.com/volcano/?p=7355
Time and magnitude of earthquake 19 Feb 10:10 GMT
Meus amigos esta crise sísmica deve ser acompanhada com atenção...
The Civil defence and emergency unit of Iceland has just declared "uncertainty level" due to the earthquakes in Northern Iceland
Dias Miguel
Cumulonimbus
Estive a consultar o google maps e surge uma pequena ilha nessa área (Grimsey), povoada, mas que não me parece ter qualquer estrutura vulcânica. Parece-me que, ao existir algum fenómeno vulcânico, deverá ser subaquático.
Do pouco que sei de vulcanologia da Islândia, recordo-me de ler que, a evolução da ilha (ou seja a sua provável expansão) ocorria prioritariamente a Sul, como é exemplo a ilha de Surtsey. Agora erupções ou ampliação a norte, creio que nunca tinha ouvido falar...
Esta crise sísmica é perto de um vulcão submarino chamado Nafir, que fica a E da ilha de Grímsey.Estive a consultar o google maps e surge uma pequena ilha nessa área (Grimsey), povoada, mas que não me parece ter qualquer estrutura vulcânica. Parece-me que, ao existir algum fenómeno vulcânico, deverá ser subaquático.
Do pouco que sei de vulcanologia da Islândia, recordo-me de ler que, a evolução da ilha (ou seja a sua provável expansão) ocorria prioritariamente a Sul, como é exemplo a ilha de Surtsey. Agora erupções ou ampliação a norte, creio que nunca tinha ouvido falar...
lserpa
Cumulonimbus