Uitbarsting vulkaan IJsland #15 Nog 3 op de nominatie!

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Op maandag 1 november 2010 15:40 schreef Roel_Jewel het volgende:

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De gevolgen van de uitbarsting in 1996 zijn nu nog goed te zien. Grote vlakte waar helemaal niets groeit...

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Op maandag 1 november 2010 15:52 schreef Roel_Jewel het volgende:

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Zorgde destijds wel voor veel problemen omdat de ringroad over een hele afstand werd weggespoeld. Naar schatting 10 miljard liter water kwam toen naar beneden zetten .

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Flood in south Iceland could suggest possible volcano eruption

Flooding began in the Gigjukvisl river in the south of Iceland yesterday afternoon after a small earthquake occurred at the Grimsvotn volcano in Vatnajokull. Gunnar Sigurdsson, a Hydrographic specialist working for the Icelandic Met Office (Vedurstofa Islands), told mbl.is that it may take 4-5 days for the flooding to reach a peak.
Sigurdsson said, “The river flow is currently measuring 140 cubic meters per second which is about two times higher than a normal glacial river but it is still not very high compared to other floods. However, I except this number to increase over the coming days.”

Pall Einarsson, a geophysicist at the University of Iceland, also told mbl.is that the likelihood of the Grimsvotn volcano erupting following the end of the flood is not unlikely, although, it is somewhat difficult to predict at this early stage.
“In 2004, sufficient pressure accumilated in the magma chamber under Grimsvotn volcano. The same thing is happening now – there is currently a lot of magma in the magma chamber under pressure and it is therefore possible that the events of 2004 will repeat themselves.”
Hydrographic specialists will continue to monitor the flood tomorrow and the day after and activity at the Grimsvotn volcano will also be monitored.

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Uncertainty level declared for Grímsfjall volcano
Posted on November 1, 2010 by Jón Frímann
The Civil defense organization in Iceland (Almannavarnir) have declared a uncertainty level over Grímsfjall volcano due to glacier flood coming from them. This level is the lowest level of warning that Almannavarnir have in case when there is a risk of dangerous events taking place.

At current time no eruption has started in Grímsfjall volcano. Note that this volcano is often called Grímsvötn in Iceland. But it is the same location with two names.

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Op maandag 1 november 2010 19:04 schreef Momo... het volgende:
Ik hoop dat die uitbarst Staat er ergens een webcam op deze vulkaan?

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Op dinsdag 2 november 2010 00:05 schreef SpeedyGJ het volgende:
Ik ga wel even voor draadloos stroom zorgen + live stream
ONEE!!! Gewoon lekker de beelden voor me zelf houden en lekker door verkopen

Maar het gaat iig lekker met de vulkanen, nog even en alle vulkanen ontploffen tegelijk in een tijdbestek van amper 1 uur, serieus dat gaat niemand overleven

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Current activity in Iceland (01.11.2010)

By Rikke Pedersen and Páll Einarsson

Grimsvötn volcano situated near the center of the Vatnajökull ice cap in central Iceland, is one of Iceland's most active volcanoes. It has a complex of calderas and a subglacial caldera lake sustained by geothermal heat. An expedition of the glaciological group of IES at the beginning of October 2010 reported that the lake level was comparable to the level prior to the jökullhlaup (episodic rapid water drainage) in 2004. The pressure decrease following the 2004 water discharge, where about 0.7 km3 of water were removed in a matter of days, is thought to have acted as a trigger for the subsequent Grimsvötn 2004 eruption (see more at http://www.jardvis.hi.is/page/ies_grimsvotn2004).

Tremor at the Grimsvötn seismometer (run by the Icelandic Meterological Office, www.vedur.is) can be used as an indicator for the onset and development of a Jökullhlaup from the subglacial lake. The tremor has therefore been closely monitored since the report from the glaciological expedition, as a jökullhlaup has been anticipated.

The first signs of increased tremor started to show on Thursday (28/10/2010) followed by several days of steady tremor increase. A strong storm during the weekend caused additional disturbances superimposed on the signal from the jökullhlaup, but the steady increase was still apparent at the end of the storm, and the general pattern follows the trend observed prior to the outbreak of the 2004 jökullhlaup.

A jökullhlaup from the Grimsvötn subglacial lake was confirmed in the afternoon of the 31/10/2010. The water drainage in Gígjukvísl (south rim of Vatnajökull) has increased more than 300% within the past 24 hours and is still increasing.

As the conditions in the Grimsvötn volcanic system (high magma pressure is indicated by GPS measurements) appears to be comparable to the state prior to the 2004 jökullhlaup and subsequent eruption, there is an increased likelihood of an imminent eruption from the Grimsvötn volcano in the following days.

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Grímsvötn volcano - Status Report: 17:00 GMT, 1 November 2010 (01.11.2010)

Icelandic Meteorological Office and Institute of Earth Sciences, University of Iceland

Compiled by: Thorunn Skaftadottir, Egill Axelsson, Rikke Pedersen, Gunnar B. Gudmundsson and Matthew J. Roberts.

Based on: IMO seismic monitoring; IES-IMO GPS monitoring; IMO hydrological data.

Meltwater: On 29 October, water began to drain from Grímsvötn, a subglacial lake near the centre of the Vatnajökull ice cap. Discharge from the lake is draining via the glacier Skeiðarárjökull, on the southern flank of the ice cap. The outburst flood (jökulhlaup) is affecting the Gígja river, with discharge increasing progressively since 30 October. Discharge was measured at 144 m3/s on 30 October. A discharge measurement this morning gave 455 m3/s, and another measurement, around 16:00 GMT, showed an increase to 627 m3/s. Electrical conductivity has increased since the beginning of the outburst from 180 µS/cm to 320 µS/cm.

Seismic tremor: Seismic tremor has been increasing at seismic station ‘grf’, located near Grímsvötn, since late on 27 October 2010. This tremor is similar in character to the tremor that accompanied the jökulhlaup in November 2004. Presently, there is no sign of volcanic tremor.

Earthquakes: An earthquake of about magnitude three occurred at the Grímsvötn volcano early yesterday morning. Three earthquakes have occurred beneath Grimsvötn today: 02:47 GMT, size 0.9; 03:12 GMT, size 1.7; and 16.56 GMT, size 2.8. Several ‘icequakes’ have been recorded in Skeiðarárjökull; this is an indication that floodwater is propagating beneath the glacier.

GPS deformation: The GPS time-series has been showing signs of a relatively stable pressure increase since the eruption in 2004. The vertical signal is difficult to estimate, as the decrease in load due to glacial thinning contributes a large part in the signal. However, horizontal movements indicate that the pressure level may be comparable to the situation before the 2004 eruption. The horizontal displacement rate has increased in recent months.

Overall assessment: On 29 October it was verified that a glacial outburst flood (jökulhlaup) had began from the Grimsvötn volcano. The Gígja river, south of the volcano, shows a considerable increase in water-level and electrical conductivity. Presently, there are no detectable signs of the beginning of a volcanic eruption at Grimsvötn

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Op dinsdag 2 november 2010 17:43 schreef Roel_Jewel het volgende:
http://twitter.com/gislio


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Op dinsdag 2 november 2010 20:30 schreef DemonRage het volgende:
Kewl! Weer spanning & sensatie uit IJsland.

Eerst Eyjafjöll in april en nu Grímsvötn. Zijn dit de voorgerechtjes voordat Katla gaat?

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Op dinsdag 2 november 2010 22:36 schreef SpeedyGJ het volgende:
Zou Katla mee gaan als deze kaboem gaat zetten?

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03.11.2010 | 07:11
Glacial Flood Reaches Maximum. No Sign of Eruption
The water level in Gígja River has been rising. On Wednesday morning early the level was at 4.8 meters and the flow was 1,650 cubic meters Tuesday night. This compares with 3.8 meters and 630 cubic meters on Tuesday morning.

The Grímsvötn eruption in 2004. Photo: Páll Stefánsson/Iceland review
According to mbl.is Gunnar Sigurdsson from the Icelandic Meteorological Office said on Tuesday night that the river had expanded to its maximum level at the bridge over the river. He yesterday went to the origin of the river up at the glacier and said that it looked much different from the previous day. Many lagoons and ponds had formed by the end of the glacier in a 24 hours space. Sigurdsson said that some of the water from Grímsvötn volcano had flowed into the Súla River. However, the flow in Súla is very limited.

No earthquake activity has been recorded in Grímsvötn in the last 24 hours.

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Op woensdag 3 november 2010 10:14 schreef SpeedyGJ het volgende:
Stijgende lijnen, geen aardbevingen? Hmmz dat wordt een knal als je het zo zou bedenken. Bevingen = ruimte maken en het laat er zo uit lopen. Maar wat als er nou geen bevingen zijn, dan zou de boel toch gaan exploderen?

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Grímsvötn
De Grímsvötn (IJslands: Grímur=masker, vatn = meer, het meer is door een 'masker' van ijs bedekt) is de naam die wordt gegeven aan zowel een vulkaan als enkele subglaciale meren, die in het IJslandse middelgebergte onder de ijskap van de gletsjer Vatnajökull verborgen liggen. Deze meren ontstaan doordat er zich onder de ijskap een magmakamer bevindt, die het bovenliggende ijs doet smelten.

Grímsvötn 1972
Net als alle andere vulkanen van IJsland wordt ook deze zeer nauwlettend geobserveerd. Hieraan is te danken dat in 1996 een door een vulkaanuitbarsting ten noorden van de Grímsvötn 1996 veroorzaakte gletsjerdoorbraak (IJslands: jökulhlaup) relatief goed afliep. De uitbarsting werd gedurende twee dagen ervoor voorafgegaan door een reeks aardbevingen en een wolk van rook en as. De hoeveelheid water in de meren steeg door het smelten van het ijs en brak uiteindelijk door de ervoor gelegen ijswal heen. Daarbij was ook de Bárðarbunga vulkaan actief.
Het hete water en modder stortte zich in de rivier Skeiðará, die met een hoeveelheid tot 45.000 m3 per seconde het rivierdal in stroomde, waardoor het erachter gelegen natuurgebied onderliep. De rondweg rond IJsland (Hringvegur) was reeds enkele dagen van tevoren afgesloten. Deze weg werd door de overstromingen en de meegekomen ijsbergen - waarvan vele tot 10m hoog waren en meerdere tonnen wogen - op meerdere plaatsen zwaar beschadigd. Een brug werd volledig vernield. Bij dit natuurgeweld liep evenwel niemand verwondingen op.
Op 1 november 2004 barstte de vulkaan opnieuw uit en slingerde een 13 kilometer hoge aswolk in de atmosfeer. Er vielen geen gewonden omdat de vulkaan in een onbewoond gebied in het zuidoosten van het eiland ligt. Het luchtverkeer werd ruim om de aswolk omgeleid. Als oorzaak voor de uitbarsting noemen onderzoekers de gestegen druk van een meer onder de Vatnajökull dat leidde tot het barsten van het onderliggende gesteente waardoor het lava vrij kwam en kon uitstromen.