Oh oh...nexttwitter:jonfr500 twitterde op donderdag 14-09-2017 om 19:38:21 Sharp increase in earthquakes in Örćfajökull volcano, https://t.co/eFNVDwXeBZ reageer retweet
twitter:subglacial twitterde op dinsdag 24-10-2017 om 12:29:16 Small earthquakes continue at ice-capped #Öraefajökull #volcano. In 1362 AD it produced #Iceland's largest historic… https://t.co/ubBuHt6nZL reageer retweet
quote:Next eruption of Bardarbunga volcano could come soon
Massive volcano in Iceland is ready to BLOW - and experts warn it could cause travel chaos
The Bardarbunga volcano has been hit by a series of earthquakes in recent days
One of Iceland's biggest volcanoes is preparing to erupt, and experts warn the ensuing ash cloud could cause travel chaos across Europe.
The 6,590ft Bardarbunga volcano, which is hidden under the ice cap of the Vatnajokull glacier, has been hit by a series of earthquakes in recent days, measuring 3.9, 3.2, 4.7 and 4.7 on the Richter scale.
Now scientists are warning that pressure inside the volcano's magma chamber is increasing, suggesting it could erupt within the next few years.
Volcanology expert Páll Einarsson told the Daily Star that the latest quakes are part of a series that have been "in progress for two years", claiming that the volcano is "clearly preparing for its next eruption".
Disaster expert Dr Simon Day, of University College London, added that the earthquakes could "precede a large explosive eruption and consequent widespread ash fall".
The Icelandic Met Office has listed activity levels at the volcano as "high", but has not yet issued a warning.
Bardarbunga is one of the most active of Iceland's 130 volcanoes. Its last eruption in 2014 was the strongest in Europe for more than 240 years.
The eruption blew out two cubic kilometers of volcanic material over the course of several months - nearly ten times more than the Eyjafjallajokull eruption in 2010, which grounded 100,000 flights across Europe.
However, Dr Thomas Walter, from the GFZ German Research Centre for Geosciences, said that the 2014 Bardarbunga eruption could have been a lot worse.
"The event was a blessing in disguise as the eruption could have happened directly beneath the ice," said Dr Walter.
"In that case, we'd have had a water vapour explosion with a volcanic ash cloud even bigger and longer lasting than the one that followed the eruption of Eyjafjallajokull in 2010."
Einarsson told the Star it is "impossible" to predict when the Bardarbunga volcano will erupt again, but said Icelandic authorities must take action to prepare for "more disastrous eruptions"
https://imgur.com/gallery/1RCJL voor 2 plaatjes/videos (embedden lukt hier niet, .mp4)quote:Yellow alert put up for Örćfajökull volcano
The new caldera can be seen clearly on this image.
Image 1 of 2 The new caldera can be seen clearly on this image. Photo/Ágúst J. Magnússon
A new caldera, measuring a diameter of one kilometres has been formed in this last week in Örćfajökull glacier, a caldera spotted via satellite images of the glacier.
Iceland's volcanoes may be ready to blow
According to the Iceland Met Office this caldera shows increased activity in Örćfajökull which is located in Vatnajökull, Iceland's largest glacier.
A great sulphuric stench has eminated from the river Kvíá last week.
Increased seismic activity has occured in the area in recent months, activity which has subsided in recent days. The volcano hasn't erupted since 1727. There are still no signs of an imminent eruption states an announcement from the Met Office. However, the safety code has been put up to yellow.
quote:Bárđarbunga trembles: 4.1 magnitude quake on Saturday
Determined not to let Örćfajökull and Skjaldbreiđur hog all the attention over the weekend, the monster volcano Bárđarbunga trembled on Saturday morning. A powerful 4.1 magnitude quake was detected at 6:19 AM on Saturday morning, in the southern edge of the volcano's caldera.
Read more: Scientists determine sub-glacial volcano Bárđarbunga is showing increased geothermal activity
Bárđarbunga has been showing high levels of activity for more than a year now, caused by the re-filling of the magma chambers of the volcano following the 2014-15 Holuhraun eruption. The last major quake in Bárđarbunga was on December 3. Seismologists at the Icelandic Meteorological Office say there are no signs of imminent volcanic activity in Bárđarbunga.
quote:Intense earthquake swarm at Tjornes fracture zone
An intense earthquake swarm is taking place at Tjörnes Fracture Zone volcano near Grimsey island, Iceland over the past 7 days. More than 1 100 of earthquakes were detected in this region since Wednesday, February 14, 2018. The last known eruption of this submarine volcano was in 1868.
The largest earthquake so far was M4.1 at 19:37 UTC on February 15, about 10 km (6.2 miles) ENE of Grimsey. "It is the largest earthquake detected in the seismic swarm that began a week ago and is still ongoing," the Icelandic Met Office said late Thursday. EMSC registered this quake as M3.7 at a depth of 14 km (8.7 miles).
A magnitude 3.2 earthquake occurred at 19:28 UTC in the same area, followed by two events above M3, at 19:38 and 19:39 UTC.
There are no signs of volcanic unrest, IMO said. "This area is part of the Tjörnes Fracture Zone and earthquake swarms are common in the area."
More earthquakes, even bigger, cannot be ruled out, the agency added.
A total of 1 165 earthquakes were detected since 08:56 UTC on February 14. 11 of them had magnitudes above 3, 162 between 2 and 3, 951 between 1 and 2 and 41 less than 1.
leuke swarm inderdaad, groter dan normaal, maar de update van 20 februari geeft aan dat er geen harmonic tremor is waargenomen en de conclusie is dan ook dat het tectonic van aard is.quote:Op vrijdag 16 februari 2018 11:35 schreef Frutsel het volgende:
of 1 165 earthquakes were detected since 08:56 UTC on February 14. 1
quote:M4.1 earthquake hits Bardarbunga volcano, Iceland
Magnitude 4.1 earthquake was registered in the southern part of the Bardarabunga volcano caldera, Iceland on March 21, 2018. The quake hit at 22:56 UTC at a depth of 4.5 km (2.8 miles).
It was followed M2.6 at 23:02 and 2.5 at 00:38 UTC, March 22 and half a dozen of smaller quakes, but there are no signs of volcanic tremors.
These are the first quakes in the volcano since the end of January when Bardarbunga was hit by the largest quake since the end of the 2014/15 eruption.
Bardarbunga earthquakes March 21 and 22, 2018
Bardarbunga, one of the most powerful volcanic systems in Iceland, has been showing a significant level of activity in recent months, Iceland Magazine reports. These quakes are caused by magma being thrust from the Earth's mantle up into the lava chambers of the volcano. The volcano has been re-filling it's lava chambers since the end of the 2014-15 Holuhraun eruption.
quote:Örćfajökull volcano showing clear signs of unrest, Iceland
Örćfajökull volcano in southeastern Iceland, the largest active volcano and the highest peak in Iceland, is showing clear signs of unrest with an inflation phase for at least a year and a half. The last eruptive episode of this volcano started in August 1727 and ended in May 1728.
The inflation is ongoing and is reflected by increased seismicity and characteristic deformation pattern, Icelandic Department of Civil Protection said July 13, after a series of meeting with scientists from The Icelandic Meteorological Office, The University of Iceland and Iceland Geosurvey.
There are no signs of a decrease in the inflation rate or the seismicity and the state of unrest persists despite a decrease in geothermal activity since last December.
The source causing the inflation is most likely injection of new magma, scientists said. The volume change since the start of the unrest is of the order of magnitude of 10 million m3 (about 0.2 m3/sec) comparable to the intrusion activity in Eyjafjallajökull some years before the eruption in 2010.
New resistivity measurements indicate the presence of geothermally altered rocks at shallow levels inside the caldera consistent with intermittent high-temperature geothermal activity as seen in many other volcanoes.
Referring to possible scenarios and hazards, scientists said that Örćfajökull is in a typical preparation stage before an eruption but the temporal evolution and the outcome is unknown. Increase in the geothermal activity with associated floods and gas release is a possible scenario.
http://www.jonfr.com/volcano/?p=7615twitter:jonfr500 twitterde op donderdag 02-08-2018 om 10:56:55 Earthquake activity in Katla volcano at the moment. There is also something going on in Vatnajökull glacier. Not sure what. reageer retweet
http://en.vedur.is/earthquakes-and-volcanism/earthquakes/quote:Considerable earthquake swarm in Katla volcano
Since early this morning (2-August-2018) there has been considerable earthquake swarm activity in Katla volcano. This earthquake swarm started yesterday (1-August-2018) at low rate but during the night and after a minor stop the earthquake rate increased and at the moment this earthquake swarm can be considered ongoing.
Green star is the magnitude 3,6 earthquake in Katla volcano. Copyright of this image belongs to Icelandic Met Office.
Largest earthquake so far had a magnitude of 3,7 and the second largest magnitude has been 2,2. Other earthquakes are smaller in magnitude at the moment. No change in harmonic tremor has been observed at the moment. There is a lot suggesting that glacier water from hydrothermal areas under Mýrdalsjökull glacier are now flooding into Múlakvísl glacier river. I got a report of that over facebook yesterday, but nothing has been confirmed officially at the moment.
quote:Sleeping giant volcano Katla trembles: Sharp earthquake swarm in caldera
Katla, a giant volcano hidden beneath the ice cap of Mýrdalsjökull glacier in South Iceland, which towers over the town of Vík, has been relatively calm and quiet for several months, following growing signs of activity in the past couple of years. Seismic activity in Katla is taken very seriously, as the volcano is under close supervision, as the volcano has erupted very regularly every 60-80 years. The last eruption took place in 1918, making Katla long overdue for an eruption.
The National Seismic Monitoring System of the Icelandic Meteorological Office recorded the earthquake swarm yesterday evening. The largest of the nearly two dozen quakes was a relatively powerful 3.1 magnitude quake at 21:39 (9:39 pm). This quake had an epicenter 6.5 km (4 mi) east-northeast of Gođabunga peak (29 km/18 miles, north-northwest of Vík) at a depth of 100 meters (330 ft). The initial tremor was followed by close to a dozen smaller tremors.
quote:Nine Hundred Quakes in Ongoing Earthquake Swarm
An earthquake swarm has been ongoing around Öxarfjörđur in northeast Iceland since Saturday. According to Einar Hjörleifsson, a natural disaster expert with the Icelandic Met Office, there have been a total of 900 quakes since the swarm began on Saturday. The swarm is on-going and currently shows no signs of subsiding.
The majority of the quakes have taken place about six kilometres south of the village of Kópasker. Eight quakes have been measured above 3.0 on the Seismic Magnitude scale, the most powerful of which took place at 8:30 pm on Wednesday night and measured 4.2. Thirty seconds later, a quake measuring 3.3 occurred; quakes of 3.3 and 3.2 followed at 9:47 pm and 9:49 pm. Smaller shocks were detected after these larger quakes.
While residents of Kópasker have felt the quakes extremely well, they haven’t been discernible elsewhere, which Einar Hjörleifsson, the Icelandic Met Office’s natural disaster expert, says is normal given the quakes’ size and location. The quakes are taking place along the Tjörnes Fracture Zone, which stretches from all the way up at Grímsey island off of the north coast of Iceland to Landey island just off the coast of Stykkishólmur in Snćfellsnes, West Iceland.
Einar says that the current swarm hasn’t gathered momentum, but it also hasn’t shown signs of losing any, either. The fracture zone has built up a lot of tension and one of two situations is most likely. Either the swarm will slowly fade out, or the built-up tension could cause a larger earthquake, up to 6.0 on the Seismic Magnitude scale. Inhabitants in towns on the north coast of Iceland are advised to make sure all furniture is secure in the case of a larger earthquake and to review the Department of Civil Protection and Emergency Management’s contingency plans.
Kópasker has been the site of numerous powerful earthquakes and earthquake swarms. On January 14, 1976, quakes measuring 5.5 to 6 damaged most of the homes in the village and necessitated the evacuation of women, children, and the elderly. Similar earthquake swarms also occurred in the area in May 1997, April 2007, April 2009, and October 2014.
quote:Increased seismicity under Loki-Fögrufjöll volcano (Hamarinn), Iceland
Increased seismic activity is taking place under Iceland's Hamarinn volcano, a part of Bardarbunga volcanic system, also known as Loki-Fögrufjöll.
The largest earthquakes over the past 48 hours were two M2.8 registered at a depth of 11 km (6.8 miles) at 20:46 and 20:47 UTC. 6 other earthquakes were registered by IMO during the same period, ranging from M0.5 - 1.4 (depths 0.5 km / 0.3 miles - 11 km / 6.8 miles).
The last time Hamarinn volcano had this type of earthquake activity was in 2011, Jon Frimann reports. Increased seismic activity lasted for several months before a glacial-outburst flood event (jökulhlaup) started on July 13, 2011.
Around 280 earthquakes were located by the IMO from August 5 - 11, 2019, similar to the previous week, when 250 were located. The largest earthquake, a M2.9 occurred at 13:53 UTC on August 11, some 20 km (12.4 miles) NW of Gjögurtá. More earthquakes were detected in North Iceland and Vatnajökull glacier. The intensity increased on the Örćfajökull volcano. Two minor earthquakes where detected in Hekla, all smaller than M1.0.
quote:Earthquake swarm in the Tjörnes Fracture Zone, Iceland
A seismic swarm began on October 19, 2019, in Öxarfjörđur, Tjörnes Fracture Zone, North Iceland.
The swarm is located around 28 km (17 miles) WNW of Kópasker and Icelandic Met Office's (IMO) seismic network has detected roughly 500 earthquakes since it started, IMO reported 12:48 UTC on October 21.
The three largest earthquakes so far are M3.2 and occurred on October 20 at 11:03, M3.5 at 19:19 and M3.1 at 22:21 UTC. Magnitude of most of the earthquakes is between M1.0 and M2.0.
The IMO said it has received reports of the largest earthquakes being felt in nearby towns
The seismic swarm is located on the Tjörnes Fracture Zone but an intense swarm occurred there in March this year.
In that swarm, around 2 600 earthquakes were measured during one week by IMO‘s seismic network. The largest earthquake in that swarm was M4.2. Then the earthquakes were located closer to Kópasker or around 6 km (3.7 miles) SW of the town.
The offshore Tjörnes Fracture Zone is an oblique transform zone that separates the northern volcanic zone of Iceland from the Kolbeinsey Ridge, part of the Mid-Atlantic Ridge north of Iceland.
A submarine eruption was reported from 1867 to 1868 at the SE part of the fissure system off the northern coast of Iceland along the Manareyjar Ridge immediately north of Manareyjar Island.
quote:Earthquake swarm under Askja volcano, Iceland
Hundreds of earthquakes have been registered near the Askja caldera, in an area approximately 10 km (6 miles) east-northeast from the rim, at the depths around 5 km (3 miles) over the past couple of days. The last eruption of this volcano took place in 1961 (VEI 2).
A total of 316 earthquakes were registered in 48 hours to 19:35 UTC on November 11. 270 had magnitudes up to 1.0, 59 up to M2.0, 6 up to M3.0 and 2 over M3.0.
Over 550 small quakes have been recorded during the past five days.
The largest quakes so far were M3.4 (1.6 km / 0.9 miles E of Dreki) and 3.2 (1.8 km / 1.1 miles E of Dreki), on November 9 and 10, respectively. Both were felt by locals.
"This earthquake swarm continues to appear to be only tectonic in nature and there are no signs of magma movement in the shallow levels of the crust on nearby SIL stations. It is not possible to know for sure what is happening in deeper levels of the crust," Jón Frímann Jónsson of Iceland Geology said November 10.
"There is a chance this earthquake swarm is going to increase before this activity slows down. What happens next depends on the built-up stress levels in the crust in Askja volcano."
quote:Update three on earthquake activity in Askja volcano
This is a short update on the earthquake activity in Askja volcano.
Earthquake activity has now moved to a new phase in Askja volcano. This appears to be a rifting event taking place in Askja volcano. They do often result in a fissure eruption of lava and sometimes short lived volcano ash event. That might not happen and as of writing of this article no magma movement has been seen on nearby SIL stations. That might change without warning at any time.
It is not possible to know what happens next in this earthquake activity in Askja volcano. The only thing that can be done is to wait and see what happens.
quote:Update four on earthquake activity in Askja volcano
Yesterday (13-November-2019) has been a little quieter in the earthquake swarm in Askja volcano. Largest earthquake in the last 24 hours had a magnitude of Mw3,1. Over the last 48 hours around 500 earthquakes have happened in Askja volcano. There was a peak in activity after the magntidue Mw3,1 earthquake but it slowed down soon after that. Depth of this earthquake swarm has changed slightly, deepest points are now at 7 to 8 km and that might be a problem since magma is possibly at 10 to 15 km depth in this location. If this is a magma that can erupt I don’t know, if there is magma at this location it might also be a magma that’s too cold to erupt.
The earthquake activity in Askja volcano. Copyright of this image belongs to Icelandic Met Office.
The earthquakes continue to be rift-zone earthquakes along fault lines and there is as of the writing of this article no signs of magma movement in Askja volcano as a result of this earthquake swarm. This earthquake swarm has been going on for a week from today (14-November-2019). It is a question if this earthquake swarm is over or if this is just a quiet time in this earthquake swarm activity. It is known in Askja volcano eruption history that eruption in Askja volcano and nearby fissure swarms start with long period of earthquake activity that continues to grow over time. This can be read in this studies of earlier eruptions, study 1961 eruption, study 1875 eruption. Current situation continues to keep monitoring what is going on.
Daar gaat het goed los!quote:
quote:Earthquake swarm at Reykjanes system - Askja continues
An earthquake swarm started on Reykjanes ridge, 45 km (28 miles) SW of Reykjanes, Iceland, around 12:00 UTC on November 16, 2019. As of early November 17, the swarm seems to be decreasing. The last confirmed eruption at this system took place in 1926 (VEI 0) NE of Eldey and lasted about 4 days. Six volcanic eruptions have occurred since 1 211 CE, on average every 130 years. The duration of these submarine eruptions is estimated based on contemporary records, and varies from a few days up to few weeks.
According to data provided by Icelandic Met Office (IMO) at 09:24 UTC on November 17, roughly 30 earthquakes above M3.0 and nearly 300 smaller earthquakes have been detected in the area since the swarm started.
The largest earthquake in the swarm was M4.5 at 13:17 UTC on November 16.
The IMO has received reports of the earthquakes being felt in the Reykjanes peninsula, the capital area and Akranes.
The Eldey volcanic system has been moderately active in Holocene time. The system is located on the northernmost part of the Reykjanes Ridge and is submarine with the exception of the island Eldey, and the skerries Eldeyjardrangur, Geirfugladrangur and Geirfuglasker. Maximum water depth within the system is about 250 m (820 feet).
The characteristic activity is submarine/explosive basaltic eruptions. Six small submarine/explosive eruptions have been located within this system during the last 1 100 years, the last eruption occurring in 1926 CE.
Possible eruption scenarios
Small eruptions (tephra fallout and lava flows <0.1 km3, recurrence time ~130 years)
Six small eruptions have occurred in historical times, the last one in 1926 CE. Eldey volcanic system is submarine and therefore all eruptions occur out in the ocean. Precursory activity is unknown but increased seismicity is expected.
This scenario starts with a fully submarine eruption at depths of 100 - 260 m (328 - 853 feet). Most of the erupted material will be deposited as hyaloclastites on the seafloor, but some may reach above the sea surface. If the eruption reaches above the water level, it will produce Surtseyan-type explosions. These explosions are relatively mild, with most of the tephra deposited in the ocean in the vicinity of the vent. The volcanic plume will be formed of seawater vapor, the plume height may reach several km. An eruption at the northeastern tip of the Eldey system could possibly deposit tephra at the international airport Keflavik. With reference to known distribution patterns of tephra from the submarine part of the Reykjanes volcanic system, a 0.5 - 1 cm (0.19 - 0.39 inches) thick tephra layer could - possibly - be deposited at the airport.
The eruption duration is several days or weeks. Some local disturbance to ship traffic may happen. If the eruption continues for longer than several days, the tephra may begin to form a small island above sea level. Subaerial lava flows are highly unlikely. The island is unlikely to be long-lived and will be eroded away on a timescale of weeks or months.
Moderate to large eruptions (0.1 -0.5 km3; >0.5 km3)
No eruptions in historical times.
Largest known eruption
In the largest submarine eruptions in the Eldey volcanic system one or more volcanic islands rose above sea level but their age, area or volume is not known. The Eldey island is the only remaining one. It may initially have risen about 100 m (328 feet) above sea level (currently 70 m / 229 feet a.s.l.). Maximum water depth is 250 m (820 feet) and a 350 m (1 148 feet) high edifice can be envisaged. For comparison the Surtsey volcanic island (within Vestmannaeyjar volcanic system) was about 1 100 m (3 608 feet) long, 800 m (2 624 feet) wide and 160 m (524 feet) a.s.l. after erupting for 10 weeks (original water depth at eruption site 130 m (426 feet)).
An explosive submarine eruption at the northeastern tip of the Eldey system could possibly deposit tephra at the international airport Keflavik. With reference to known distribution patterns of tephra from the submarine part of the Reykjanes volcanic system, a 0.5 - 1 cm (0.19 - 0.39 inches) thick tephra layer could - possibly - be deposited at the airport.
Askja volcano earthquake swarm continues
Meanwhile, earthquakes are still being detected in the earthquake swarm around Askja.
A total of 166 earthquakes were recorded in the region in 24 hours to 11:05 UTC on November 17.
quote:Unusually rapid inflation detected beneath Mt. Thorbjorn, Aviation Color Code raised to Yellow, Iceland
According to the Icelandic Met Office (IMO), unusually rapid inflation has been detected at Mt. Thorbjorn on the Reykjanes Peninsula over the past few days, indicating a possible magma accumulation. In addition, an earthquake swarm has been ongoing during the same period. Authorities have declared Uncertainty phase and raised the Aviation Color Code to Yellow. The last known eruption was during Reykjanes fires, which occurred between 1210 - 1240.
Inflation centered just west of Mt. Thorbjorn accompanied by an earthquake swarm just east of the inflation center (northeast of Grindavík) have been detected since January 21, 2020.
The fact that inflation is occurring alongside the earthquake swarm is a cause for concern and closer monitoring, IMO said.
"The inflation is unusually rapid, around 3 - 4 mm (0.11 - 0.15 inches) per day and has accumulated to 2 cm (0.78 inches) to date. It has been detected both on continuous GPS stations and in InSAR images," the office said, adding that the inflation is most likely a sign of magma accumulation at a depth of just a few km.
If magma accumulation is causing the inflation, the accumulation is very small, with the first volume estimate is around 1 million cubic meters (0.001 km3 / 0.0002 mi3). This is the conclusion of a meeting held with the Scientific council of the Civil Protection at the IMO this morning.
Accurate measurements of crustal deformation on the Reykjanes peninsula span approximately three decades. During this period no comparable signal has been measured.
This is unusual for this period, IMO said.
The last known eruption was during Reykjanes fires, which occurred between 1210 and 1240.
"Within that period, several eruptions occurred within that system, thereof there were three eruptions in the Svartsengi system. The eruptions were effusive (non-explosive) fissure eruptions erupting on 1 - 10 km (0.62 - 6.2 miles) long fissures. No explosive eruptions are known from this system. The largest eruption in the swarm, from the 13th century, formed Arnarseturshraun lava (estimated 0.3 km3 / 0.07 mi3 and 20 km2 / 7.72 mi2).
"Historically, the duration of these eruptions spans from a few days up to several weeks. Seismic activity is very common in this area and is linked to the plate boundaries, geothermal activity and possible magma intrusions. The largest earthquakes measured in this area are about M5.5."
quote:Increase in earthquake in Ţorbjörn mountain (Reykjanes volcano)
Yesterday (19-March 2020) an earthquake swarm took place close to Grindavík town (Ţorbjörn mountain). This earthquake was has several hundred earthquakes and many of the earthquakes were at shallow depth and it is not understood why that was. Largest earthquakes in this swarm had a magnitude of Mw3,0, Mw3,2 and Mw3,3. Other earthquakes that took place were smaller in magnitude. The earthquake swarm seems to be over for now but this activity happens in swarms and how long and how strong each swarm is different.
Inflation continues in this area and that is the reason why this earthquake swarm activity happens. What seems to be happening now is that more activity is happening and it is happening over a wider area. At the writing of this article there are no signs that magma is finding a path to the surface.
quote:More then 6000 earthquakes in 3 month at Reykjanes
Considerable seismic activity continues at the Reykjanes peninsula, Iceland, with more than 6 000
earthquakes manually checked since the beginning of the year. According to the Icelandic Met Office (IMO), this is the most intense activity ever recorded in the region since the beginning of digital monitoring in 1991. Data indicates the activity is affecting all volcanic systems in the Reykjanes peninsula and Reykjanes ridge. In addition, GPS measurements, as well as detailed analysis and model calculations of the available data, now give evidence of a new magma deposit west of the Reykjanes peninsula under Rauđhólar and Sýrfell.
Recent data show that uplift has started again, with the center just west of Mt. Thorbjorn, IMO reported on April 2, 2020. Uplift was measured from January 22, 2020, until the beginning of February and has started up again during the first half of March.
During the first sequence in January-February, the deformation rate was about 3 - 4 mm (0.11 - 0.15 inches) per day with a total of 6 cm (2.3 inches) uplift during the whole period.
In the sequence that is ongoing now, the deformation rate looks to be only half of what it was (or even slower). In total, the uplift is about 7 - 8 cm (2.7 - 3.1 inches) since the end of January.
The Scientific Advisory Board (SAB) who met on March 28 still believes that the most likely explanation of the uplift is a magma intrusion where the magma is 'forcing' its way horizontally between the stratum in the crust and forming a thin sill at about 3 to 4 km (1.8 - 2.5 miles) depth. The magma intrusion causes a considerable amount of earthquakes in the area north of Grindavík. Their next meeting is scheduled for April 8.
A model of the ongoing magma intrusion shows that fissures can open in the uppermost layer of the crust, at 1 - 2 km (0.62 - 1.24 miles), because of the tensional stress induced by the uplift itself. This change in the crustal stress might lead to more earthquakes related to injection at boreholes, which was not common before in the area, IMO said.
The work procedure for the injections will be reviewed in collaboration with HS-Orka and discussion will be taken on how is the best way to monitor the earthquakes likely due to these changes, it added.
Considerable seismic activity continues at the Reykjanes peninsula, Iceland, with more than 6 000 earthquakes manually checked since the beginning of the year. According to the Icelandic Met Office (IMO), this is the most intense activity ever recorded in the region since the beginning of digital monitoring in 1991. Data indicates the activity is affecting all volcanic systems in the Reykjanes peninsula and Reykjanes ridge. In addition, GPS measurements, as well as detailed analysis and model calculations of the available data, now give evidence of a new magma deposit west of the Reykjanes peninsula under Rauđhólar and Sýrfell.
Recent data show that uplift has started again, with the center just west of Mt. Thorbjorn, IMO reported on April 2, 2020. Uplift was measured from January 22, 2020, until the beginning of February and has started up again during the first half of March.
During the first sequence in January-February, the deformation rate was about 3 - 4 mm (0.11 - 0.15 inches) per day with a total of 6 cm (2.3 inches) uplift during the whole period.
In the sequence that is ongoing now, the deformation rate looks to be only half of what it was (or even slower). In total, the uplift is about 7 - 8 cm (2.7 - 3.1 inches) since the end of January.
The Scientific Advisory Board (SAB) who met on March 28 still believes that the most likely explanation of the uplift is a magma intrusion where the magma is 'forcing' its way horizontally between the stratum in the crust and forming a thin sill at about 3 to 4 km (1.8 - 2.5 miles) depth. The magma intrusion causes a considerable amount of earthquakes in the area north of Grindavík. Their next meeting is scheduled for April 8.
A model of the ongoing magma intrusion shows that fissures can open in the uppermost layer of the crust, at 1 - 2 km (0.62 - 1.24 miles), because of the tensional stress induced by the uplift itself. This change in the crustal stress might lead to more earthquakes related to injection at boreholes, which was not common before in the area, IMO said.
The work procedure for the injections will be reviewed in collaboration with HS-Orka and discussion will be taken on how is the best way to monitor the earthquakes likely due to these changes, it added.
On Saturday, March 28, an earthquake swarm occurred in Eldey, indicating that the activity is affecting all volcanic systems in the peninsula and the ridge, eg. from Eldey all the way to Krýsuvík.
The interpretation of these events is still uncertain, but there are indications that a common underlying process is the cause of the activation of such a widespread area in such a short timeframe.
However, the Reykjanes peninsula and the Reykjanes ridge are composed of plate boundaries. Also, the Eldey, Reykjanes, Svartsengi and Krýsuvík volcanic systems lie right across the boundaries.
Because of the activity ongoing in the area, the SAB believes that it is extremely important to monitor and investigate the ongoing activity in the Reykjanes peninsula as a whole, and compare this activity with older events in the area to try to decipher the reasons and identify possible developments.
In addition, GPS measurements, as well as detailed analysis and model calculations of the available data, now give evidence of a new magma deposit west of the Reykjanes peninsula under Rauđhólar and Sýrfell.
"The data we have processed indicates that the magma insertion has taken place from mid-February until the first week of March. This picture was better explained when we got data from the University's GPS measurements, which are not directly related to our monitoring system -- meaning that we did not detect this until now," says Kristín Jónsdóttir, Group Director of Nature Conservation at the Icelandic Meteorological Office.
A model places the magma insert at a depth of about 8 - 13 km (5 - 8 miles), which is probably at the bottom of the Earth's crust at considerably more depth than the two magma deposits at Thorbjörn.
"This magma deposit under Sýrfell is the third magma deposit we report on the Reykjanes peninsula since the turn of the year. The presence of this magma insert supports the Resolution of the Swedish Civil Defense Council that it is necessary to look at the activity in the Reykjanes peninsula comprehensively, and not only from the local activity around Svartsengi and Reykjanes," Kristín said.
wat is dezetwitter:gislio twitterde op donderdag 11-06-2020 om 06:43:20 Grimsvotn #volcano in #Vatnajokull #Iceland starting to show signs of potential #eruption, such as increased output of #magma gasses, large amounts of melted water in crater, minor #earthquakes, and geothermal activity. Timeframe that scientists predict are weeks/months... https://t.co/3pX7Zivbrl reageer retweet
quote:Grímsvötn volcano showing strong signs of impending eruption, Iceland
Iceland's Grímsvötn volcano is showing strong signs that an eruption might occur in the weeks or months ahead, the Icelandic Met Office (IMO) reports. The last eruption of this volcano took place in 2011 -- it was a large and powerful VEI 4 eruption. Average eruption frequency during the last 1 100 years is 1 eruption per 10 years.
The Scientific Council of Civil Defense met at a teleconference on Wednesday, June 10, 2020, due to earthquakes in the Reykjanes peninsula and recent measurements at Grímsvötn.
The results were presented on June 15, indicating a possible eruption at Grímsvötn in the next weeks or months.
According to Melissa Anne Preffer, IMO's atmospheric volcanologist, high levels of magmatic gasses are present in the southwest corner of the volcano, near the place where it erupted in 2004 and 2011.
In addition, the volcano is experiencing inflation, indicating an increase in magma.
Scientists expect the eruption might take place in the next weeks or months, as the Grímsvötn's lake drains during summer, releasing pressure on the volcano. Given the current conditions, when the flooding starts, preparations for an eruption will begin.
The volcano's last eruption started at approximately 17:30 UTC on May 21, 2011, with a plume of volcanic ash and steam rising to about 20 kilometers (65 600 feet) above sea level. Overnight, the plume height dropped to 15 kilometers (49 000 feet), but occasionally re-approached its initial altitude.
Ash from the volcano reduced visibility to about 50 meters (160 feet) in some places and made some areas as dark as night in the middle of the day. The ash plume also prompted the closure of Keflavik, Iceland’s largest airport.
Bronquote:The Icelandic Met Office (IMO) reported that in mid-May deformation data (GPS and InSAR measurements) started to show again signs of inflation, suggesting that a third intrusion since the beginning of this year is occurring west of Thorbjörn. The intrusion began around mid of May but the seismic activity started to increase toward the end of the month (30 May). About 2000 earthquakes have been detected since then and several events are located East of Thorbjörn, few kilometers North of the town of Grindavík. The largest earthquake of this swarm occurred on 13 June with magnitude M 3.5.
Since the beginning of the volcanic unrest, in January this year, the total uplift measured in the area is assessed to be around 12 cm. Between the inflation periods, slight deflation has been observed, probably reflecting the cooling of the intruded magma or the interaction with the geothermal system. Numerical modelling results show that this third intrusion is occurring roughly in the same area as the previous ones, i.e. at about 1 km West of Thorbjörn, at a depth of 3-4 km, with a width of few hundreds of meters and oriented NE-SW for about 6 km.
Weekly gas measurements at two sites near the area of the intrusion changes occasionally over time but the interpretation is still unclear. No chemical changes have been detected at the geothermal power plant in Svartsengi. However, measurements of the geothermal system reveal an increased permeability and increased fluid flow in the surrounding rock, which can be linked to the earthquake activity, inflation and uplift in the area, which triggered the creation of new cracks and opening of older ones.
twitter:gislio twitterde op donderdag 18-06-2020 om 18:23:44 Science council of @almannavarnir on #Grimsvotn #volcano met today. According to them, the water level in Grimsvotn is raising around 3cm per day. Glacial outburst can be expected within days, weeks, or a month or two. An #eruption is likely to follow outburst. https://t.co/46pmEBAI2S reageer retweet
twitter:jonfr500 twitterde op zaterdag 20-06-2020 om 17:07:30 A strong earthquake in Iceland just now. reageer retweet
twitter:EMSC twitterde op zaterdag 20-06-2020 om 17:12:01 #Earthquake (#jarđskjálfta) M5.2 strikes 81 km NW of #Akureyri (#Iceland) 7 min ago. More info: https://t.co/d2Cimx1zdI reageer retweet
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