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Iceland warming up again - quakes swarming
DaveE said:Another video from a geologist with more seismic data.
Since the morning of November 11th, seismic activity related to the magma intrusion remains fairly constant. Since midnight November12th, around 1000 earthquakes have been recorded within the dyke, and all of them have been below M3.0 in magnitude. The most seismic activity has been located in the region north of Grindavík. Most of the earthquakes are at a depth of 3-5km corresponding to the lower part of the dyke intrusion.
GPS measurements covering the past 24 hours show that deformation associated with the dyke intrusion that formed on Friday, November 10th has slowed. This can be an indication that magma is moving closer to the surface, new models will be run as soon as new data comes in to update the model.
It was a joint assessment from the meeting, based on the latest data, that there is scope for temporary measures under the control of the Department of Civil Protection and Emergency Management to collect necessities for the residents and attend to urgent errands in Grindavík and the surrounding area.
I think it's more that the earthquakes are indicative of a magma chamber close to the surface.Vanadium 50 said:I'm not a geologist, but isn't it better to have multiple small earthquakes and eruptions ands release the energy that way than to have one big one?
https://www.msn.com/en-us/weather/t...wn-as-a-volcano-prepares-to-erupt/ar-AA1jM1GeMagma is continuing its approach to the town, prompting authorities to order an evacuation. The roads leading to Grindavik are currently closed, with inhabitants of the southwest portions being the first to leave. The Icelandic Civil Defense Agency emphasizes that this evacuation is purely precautionary.
Recent reports indicate that the magma tunnel has reached the town and crossed the coastline. It is now expanding under the sea. The Icelandic Meteorological Office predicts an eruption near Sundhnjúkagígar, north of Grindavik, could occur soon.
https://www.yahoo.com/lifestyle/volcanic-fears-river-magma-cuts-073735840.htmlA 15-kilometer- (nine-mile-) long magma corridor now stretches from just northwest of Grindavík into the Atlantic Ocean, according to the Civil Protection Agency, which used models built from data collected in the area on Saturday.
https://www.washingtonpost.com/weat...d-volcano-grindavik-reykjanes-fagradalsfjall/Icelandic officials have evacuated the town of Grindavik, warning that a volcanic eruption is imminent. Cracks have appeared in the earth there, snaking under buildings, splitting streets and pouring steam into the air. And while magma hasn’t yet bubbled to the surface, experts say it probably will soon.
Radar satellite data from the Icelandic Meteorological Office show that a broad area around Grindavík sank by about 3 feet (1 meter) over 10 days, and the GPS station in town moved about 3 feet (1 meter) to the southeast with respect to the North American plate from Oct. 28 to Nov. 9. Large cracks have broken streets and houses in Grindavík.
Where the lava reaches the surface is the concern aside from the ongoing seismic activity. In a figure showing the rise and fall of the land, Grindavik is east of the land that had the greatest level of subsidence. Interesting there are red spots in the purple that would indicate rising locations is an area that mostly subsided. Or, could that be noise? A ridge east of Grindavik has risen.The Grindavík dike appeared to have reached within about 0.6 miles (1 kilometer) of the surface by Nov. 14 and could soon reach the surface.
Iceland derives 30% of its electricity from geothermal sources that use underground heat to drive turbines and produce power.
A hydrothermal plant called Svartsengi, near Grindavík, uses the underground heat to provide hot water for several thousand homes plus 75 megawatts of electricity.
. . .
That power plant is also part of the reason the Blue Lagoon is so popular. When the power plant was built in 1976, the plan was to discharge its still hot wastewater into an adjacent low area, expecting that it would seep into the ground. However, the geothermal water was loaded with dissolved silica, which turned to minerals when the water cooled, creating an impermeable layer. A small lake began to form.
Because of its high silica content, the water in this lake is a spectacular blue color that inspired the creation of the geothermal spa. The Blue Lagoon is now one of the top tourist attractions in the country.
I think they are all evacuated from the danger zone now, but their homes are still at risk, unfortunately.Greg Bernhardt said:Fingers crossed for our Iceland friends!
Using radar imagery taken over the weekend, the Icelandic Met Office said there had been a "significant crustal uplift" near Svartsengi, a geothermal hotspot on a southwestern cape on the island, near the capital Reykjavik, which was "indicative of a deep inflation" taking place. The ground has moved upwards by as much as three centimeters.
Why is the datestamp on the video now in 2023, but in the audio the person says "here, listen to this audio from 2022"?DaveE said:Iceland eruption has started.
IDK, not my live stream, dude. Ask Shawn? Maybe they want you to listen to audio from 2022?berkeman said:Why is the datestamp on the video now in 2023, but in the audio the person says "here, listen to this audio from 2022"?
A Coast Guard helicopter flew over the eruptions this evening with scientists and civil defense representatives. Bragi Valgeirsson, RÚV's cinematographer, was with us and captured these images of the beginning of the eruption.
The location of the fissure, which is some 2.5 miles long and growing quickly, is not far from the Svartsengi Power Plant and the town of Grindavík, which was evacuated last month because of heightened seismic activity, leading to concerns than an eruption was likely.
In the initial assessment Monday night, volcanologists had said that the eruption had occurred in one of the worst possible locations, posing a significant and immediate threat to both the evacuated town and the geothermal power plant.
But after volcanologists had a chance to fly over the site of the eruption in the Reykjanes Peninsula, the immediate situation did not appear as dire as initially feared, though the size of the eruption was larger than anticipated and the direction of the lava’s flow still unpredictable.
A horizontal intrusion of magma—around 6 miles in diameter—has been building under the peninsula since November 10, and is thought to be channeling magma into a vertical intrusion—estimated to be around 9.3 miles long—near the coastal fishing town of Grindavik.
Swarms of seismic activity led to anticipation that a volcanic event was set to occur, with magma likely propagating to the surface through the vertical dike. That occurred on Monday, December 18, with lava shooting up to 650 feet into the air from five fissures in the initial phase of the eruption.
Ben Edwards, an American volcanologist who has visited the Reykjanes Peninsula multiple times, previously told Newsweek that the eruption could mark the start of over a century of volcanic activity in the region.
His remarks came after a leading Icelandic volcanologist told Newsweek that after a dormant period, the activity leading up to the eruption could mark the start of an "intense" period of "rifting and volcanism" on the peninsula.
Flyboy said:Doesn’t look very promising for the town right now.
Ref: https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-nightAn eruptionstarted at 7:57 UTC
The fissureopening is southeast of Hagafell mountain.
Thesouthern most part of the fissure is about 900 m from the town of Grindavík.
The openingis south of lava flow deflection barriers that are being built north ofGrindavík. Lava is now flowing towards the town.
Yeah, contractor working on backfilling a fissure. He was using a soil compactor and the ground opened up beneath him. They spent three days trying to find him and weren’t successful. They did, however, find out the fissures at the surface are actually quite sizable underneath and issued evacuation orders effective Monday. Looks like they were a little bit late.Astronuc said:The narrator mentions that someone fell into a fissure, but was not found!
There’s evidence for both. Best hypothesis right now is that the November 10th dike has been reactivated by fresh magma intrusion. That one is believed to have extended out under the ocean but they can’t confirm it.Astronuc said:I'm wondering if the sub-surface lava is pushing southward, or a fissure/fault is simply opening or 'unzipping' toward Grindavik.
New material erupts in the rift zones as they pull apart, separating the two major tectonic plates. In Iceland there’s a third microplate between the two rifts. The process continues through time, creating volcanic activity with ages somewhat symmetrical about each of the rifts. From the map, you can also see that most of Iceland’s big thermal areas lie within the rift zones.
Ref: BBC reporting from the area.As we've been reporting, two fissures opened today near the Icelandic town of Grindavik - both spewing lava.
The first formed early this morning around 1km (0.6 miles) from the town. You can see it at the top of the image.
Authorities say the lava flow from this fissure had largely stabilised before the second opened, around noon.
This fissure was much closer to Grindavik - less than 100m (320 feet) away.
The lava from that fissure has since spilled into the town, setting houses on fire.