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http://vefmyndavelar.mogt.is/

Unfortunately, this link does not support continuous updating of images from within the page. Therefore the images (stale-dating) have been removed from this post and interested users are directed to the link above. The web cams are not video feeds, they are image feeds, and the link webcam page is rebuilt with each update. The link above has been added to the “Active Monitoring” group in the sidebar at left. Images on the link site are 1280×960 pixels.

Bardarbunga 1

Bardarbunga 2

Unfortunately, pt.2…, it appears the webcam servers can’t handle the load, so images may or may not be available consistently.

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Please see the Icelandic Met Office for more recent information…
and some external related links…
http://baering.github.io/
This link is to a developmental visualization project of the creator of the link above – pretty spectacular…
earthquakes visualization in near real time
http://www.ruv.is/volcano
http://en.vedur.is/earthquakes-and-volcanism/articles/nr/2947


Bárðarbunga 2014 – recent earthquakes
Continually updated maps

In this article, the most recent earthquakes at Bárðarbunga are given by maps that are updated more or less continuously. Each earthquake is represented by a circle. The size of the circle indicates the magnitude. The timing is colour coded, see the bar to the right of each map. The first two maps show earthquakes counting hours since midnight but the third one shows earthquakes since the onset of this seismic event (counting days). The date and timing of each map is in the lower right hand corner (yyyymmdd 00:00).



Manually processed earthquakes since midnight:


Automatic recording of earthquakes since midnight:



Bárðarbunga earthquakes in 3D
Three dimensional video 16-20 August 2014

The Bárðarbunga seismic activity can now be explored in a three dimensional video (30 sec.) which shows earthquakes from 16th to 20th August 2014.

Location, depth and age of earthquakes in Bárðarbunga 16-20 August 2014.

The colour of the dots implies the date: First there are red dots, then orange, yellow, light-green and then green. Please note that height and depth are exaggerated five times in order to show the topography explicitly and to expand the space between the earthquakes at depth.

The magnitude of the earthquakes is not shown; all dots are of equal size in this video. The same dots are shown on the surface as at depth for better harmony between the two. The depth of the earthquakes is indicated by the horizontal planes which are set at 0 km, 5 km and 10 km depth below sea level.

IMO’s specialist, Bogi B. Björnsson, compiled this video from the available data.

Bárðarbunga – updated information

Overview of seismic events in August 2014

In this article, updated information on the Bárðarbunga seismic activity is given with daily status reports from the scientist of IMO and the University of Iceland. New material is added to the top of the article. The original information is at the end of the article. All in all, this article gives an overview of events. For additional material, check also the news list on our front page.
23rd August 2014 14:10 – a small eruption under Dyngjujökull

A small lava-eruption has been detected under the Dyngjujökull glacier.
The Icelandic Coast Guard airplane TF-SIF is flying over the area with representatives from the Civil Protection and experts from the Icelandic Met Office and the Institute of Earth Sciences. Data from the equipment on board is expected later today.
Data from radars and web-cameras is being received, showing no signs of changes at the surface.
The estimate is that 150-400 meters of ice is above the area.
The aviation color code for the Bárðarbunga volcano has been changed from orange to red.
Some minutes ago (14:04), an earthquake occurred, estimated 4.5 in magnitude.

23rd August 2014 12:20 – notes from the scientists’ meeting

Intense earthquake activity continues at the Bárðarbunga volcano – a situation that has persisted since 16 August.

During the last 6 hours the dyke has propagated ~5 km to the north. The rate of earthquakes has increased such that they are happening so quickly that it is difficult for the seismologist to discern individual events. Observed high frequency tremor is interpreted to be caused by the propagation of the dyke.

Some larger earthquakes of magnitude 3 – 4 have been measured in the Bárðarbunga caldera in the last days. These events in the Bárðarbunga caldera are interpreted as adjustments related to decompression in the caldera since the beginning of the unrest.

Most recent GPS data shows that magma flow is continuing.

The Coast Guard TF SIF aircraft is taking off by 13:00 to make observations with scientists from Icelandic Met Office, the Institute of Earth Sciences, and people from the Civil Protection.

A tourist plane called in at noon to report no visible changes at the surface.

Current winds: weak winds at low levels. At higher levels winds are northerly (towards the south).
Hydrological measurements at Jökulsá á Fjöllum, Upptypingar, do not indicate a contribution of geothermal/volcanic gases to the hydrological system that is outside of the typical range observed in the last decade.

The activity continues and an eruption can therefore not be ruled out.

The aviation colour-code for the Bárðarbunga volcano remains unchanged at ‘orange’, and we are continuously evaluating if this should be changed. The volcano is exhibiting heightened levels of unrest.
22nd August 2014 17:00 – status report

Overall assessment from the joint daily status report 220814 of the Icelandic Met Office and the University of Iceland, Institute of Earth Sciences:

There are no measurements to suggest that an eruption is imminent. Previous intrusion events in Iceland have lasted for several days or weeks, often not resulting in an eruption. However an eruption of Bárðarbunga cannot presently be excluded, hence the intense monitoring and preparation efforts. The ongoing monitoring and assessment effort is necessary in case a volcanic eruption occurs. Hazards in the event of an eruption are being assessed, including a glacial outburst flood and dispersal of volcanic ash. Additional seismic, GPS and hydrological stations have been installed in the Bárðarbunga region. Likewise, mobile radars capable of monitoring ash dispersal have been moved to the region. The aviation colour-code for the Bárðarbunga volcano remains unchanged at ‘orange’, signifying that the volcano is exhibiting heightened levels of unrest.
Bárðarbunga
“”
View to Bárðarbunga. Web camera M&T ehf.
22nd August 2014 13:00 – notes from the scientists’ meeting

Intense earthquake activity continues at the Bárðarbunga volcano – a situation that has persisted since 16 August. There are no signs that the seismicity is decreasing. A 25 km long dyke has formed in the crust under the Dyngjujökull glacier at 5-10 km depth. Interpretation of the latest data suggests that the magma continues to move along the dyke, possibly branching at the northeast end of the dyke.

One earthquake of magnitude 4.7 was measured in the Bárðarbunga caldera at 4 km depth yesterday evening at 23:50. This large event was at similar location as earthquakes of magnitude larger than three that were seen yesterday. Large events in Bárðarbunga are interpreted as adjustments of the caldera rim related to decompression in the caldera since the beginning of the unrest. The activity continues and an eruption can therefore not be ruled out.

There are no signs of increased conductivity through geothermal activity into the rivers.

From the beginning of the activity, measurements done with GPS have shown displacements on the surface of over 14 cm, 15 – 20 km from Dyngjuháls. In comparison, Iceland on the whole is spreading at the rate of about 2 cm pr. year.

A new GPS station in Kverkfjöll is now running and sending data. Similar seismic instruments were installed by Kverkfjöll yesterday, as well as close to the GPS station at Hamarinn, which was set up two days ago. In addition, two seismic stations set up in Dyngjujökull yesterday are collecting data on site. This work is done in collaboration between IMO, the Institute of Earth Sciences and collaborators in the European FutureVolc research project.

The aviation colour-code for the Bárðarbunga volcano remains unchanged at ‘orange’, signifying that the volcano is exhibiting heightened levels of unrest.
22nd August 2014 06:40 – from geoscientist on duty

Seismic activity in Bárðarbunga and Dyngjujökull is still great. It diminished somewhat after two o‘clock in the morning. Almost 400 quakes have been detected by the automatic network since midnight and, as in recent days, the majority of them is located east of Bárðarbunga, next to the intrusion. Most of the manually processed earthquakes turn out to be at great depth, 8-12 km, but a few at the very northeastern tip of the intrusion have been positioned at shallower depths, up to just under 4 km.

Just before midnight, 21st August at 23:50:22, an earthquake occurred at Bárðarbunga which measured 4.7-4.8 in magnitude. Another one reached M3. During the last days quite a number of quakes has been detected within the Bárðarbunga caldera, or on the rims, at a depth of 2-6 km. Probably these earthquakes derive from changes in pressure when magma is drawn eastward into the huge intrusion and away from the magma chamber under the caldera.
Jökulsá á Fjöllum
“”
This is where the cirle road around Iceland, road nr. 1, crosses river Jökulsá á Fjöllum, not far from farm Grímsstaðir á Fjöllum. This bridge might come under severe strain if the Bárðarbunga seismic phase leads to an eruption and a glacial outburst flood: A grave concern for the Icelandic Road and Coastal Administration. Just south of this bridge is a closed area for safety reasons. Photo: Þorsteinn Þorsteinsson.
21st August 2014 17:00 – status report

Overall assessment from the joint daily status report 210814 of the Icelandic Met Office and the University of Iceland, Institute of Earth Sciences:

There are no measurements to suggest that an eruption is imminent. Previous intrusion events in Iceland have lasted for several days or weeks, often not resulting in an eruption. However an eruption of Bárðarbunga cannot presently be excluded, hence the intense monitoring and preparation efforts. The ongoing monitoring and assessment effort is necessary in case a volcanic eruption occurs. Hazards in the event of an eruption are being assessed, including a glacial outburst flood and dispersal of volcanic ash. Additional seismic, GPS and hydrological stations have been installed in the Bárðarbunga region. Likewise, mobile radars capable of monitoring ash dispersal have been moved to the region. The aviation colour-code for the Bárðarbunga volcano remains unchanged at ‘orange’, signifying that the volcano is exhibiting heightened levels of unrest.
21st August 2014 15:00 – a few facts

Today, three earthquakes exceeding 3 in magnitude have occurred on the caldera rim of Bárðarbunga (M 3.7 at 10:29, M 4.0 at 10:58 and M 3.4 at 13:02). These earthquakes were at depths around 2 – 5 km. They are interpreted as possible adjustments of the caldera due to changing magma pressure – they are not assumed to be the precursor to an imminent eruption.
21st August 2014 12:00 – notes from the scientists’ meeting

No signs of diminishing activity around Bárðarbunga
An intrusion, 25 km long, has formed beneath Dyngjujökull, at a depth of 5-10 km
The aircraft TF-SIF, from the Icelandic Coast Guard, is now available for scientists
The aviation colour code is still orange

The seismic activity in Bárðarbunga, first noticed 16th August, has maintained its strength and there are no signs of its retreat. Deformation measurements, GPS, indicate that a 25 km long intrusion is forming underneath Dyngjujökull. Earthquake measurements support the conclusion that the magma is still at 5-10 km depth. There are no signs of upward migration of the activity.

Collateral interpretation of the latest data suggests that the intrusion is expanding at its northeastern end, whereas its length has only increased a little in the last 24 hours.

In the Bárðarbunga caldera, where it all started, earthquakes still occur; probably because of slight subsidence due to the outward flow of magma from the magma-chamber under the caldera.

The measuring network in the area is being improved; just now technicians from the Icelandic Met Office, from the Institute of Earth Sciences and from foreign research institutions are mounting additional equipment on the ice-cap and at its margin. Already, many devices which have been implanted in recent years as part of the international FutureVolc project, are running and providing important information which has been useful in both monitoring and analysis of these events.

Yesterday, a reconnaissance flight was made over the area with the Icelandic Coast Guard. The aircraft TF-SIF, now dedicated to these events, has specialised equipment on board for monitoring changes in the surface of the ice-cap and monitoring outburst floods. No signs of change were detected during this flight. With open access to this aircraft, which was withdrawn from its current tasks at the Mediterranean, scientist are now in a much better position to monitor possible volcanic activity and flooding.

[Ed. Note: crossposted from WUWT. Hawaii experienced some low amplitude tsunami waves of generally less than one meter, although evacuations of some regions were ordered in advance last night.]

7.7 Earthquake off west coast of Canada, Tsunami warnings issued

Posted on October 27, 2012 by

An earthquake with magnitude 7.7 occurred near Prince Rupert, BC, Canada at 03:04:10.56 UTC on Oct 28, 2012. (This event has been reviewed by a seismologist.)

Map below:

Open map in new window  Epicenter

BULLETIN
PUBLIC TSUNAMI MESSAGE NUMBER 6
NWS WEST COAST/ALASKA TSUNAMI WARNING CENTER PALMER AK
1044 PM PDT SAT OCT 27 2012

THE ADVISORY HAS BEEN EXPANDED TO INCLUDE NORTHERN CALIFORNIA AND
SOUTHERN OREGON.

…THE TSUNAMI WARNING CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF BRITISH COLUMBIA AND ALASKA FROM THE NORTH TIP OF
VANCOUVER ISLAND BRITISH COLUMBIA TO CAPE DECISION
ALASKA/LOCATED 85 MILES SE OF SITKA/…

…THE TSUNAMI ADVISORY IS MODIFIED TO INCLUDE THE COASTAL
AREAS OF CALIFORNIA AND OREGON FROM GUALALA POINT
CALIFORNIA/LOCATED 80 MILES NW OF SAN FRANCISCO/ TO
DOUGLAS-LANE COUNTY LINE OREGON/10 MILES SW OF FLORENCE/…

…THE TSUNAMI ADVISORY CONTINUES IN EFFECT FOR THE COASTAL
AREAS OF BRITISH COLUMBIA FROM THE WASHINGTON-BRITISH
COLUMBIA BORDER TO THE NORTH TIP OF VANCOUVER ISLAND
BRITISH COLUMBIA…

…THIS MESSAGE IS INFORMATION ONLY FOR COASTAL AREAS OF
CALIFORNIA FROM THE CALIFORNIA-MEXICO BORDER TO GUALALA
POINT CALIFORNIA/LOCATED 80 MILES NW OF SAN FRANCISCO/…

…THIS MESSAGE IS INFORMATION ONLY FOR COASTAL AREAS OF
OREGON AND WASHINGTON FROM DOUGLAS-LANE COUNTY LINE
OREGON/10 MILES SW OF FLORENCE/ TO THE WASHINGTON-BRITISH
COLUMBIA BORDER…

…THIS MESSAGE IS INFORMATION ONLY FOR COASTAL AREAS OF
ALASKA FROM CAPE DECISION ALASKA/LOCATED 85 MILES SE OF
SITKA/ TO ATTU ALASKA…
And also:

BULLETIN
TSUNAMI MESSAGE NUMBER 3
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
709 PM HST SAT OCT 27 2012

TO – CIVIL DEFENSE IN THE STATE OF HAWAII

SUBJECT – TSUNAMI WARNING

A TSUNAMI WARNING IS ISSUED FOR THE STATE OF HAWAII EFFECTIVE AT
0709 PM HST. THIS UPGRADE IS DUE TO THE SEA LEVEL READINGS
RECEIVED AND THE RESULTING CHANGE IN THE HAWAII TSUNAMI
FORECAST.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME – 0504 PM HST 27 OCT 2012
COORDINATES – 52.8 NORTH 131.8 WEST
LOCATION – QUEEN CHARLOTTE ISLANDS REGION
MAGNITUDE – 7.7 MOMENT

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION LAT LON TIME AMPL PER
——————- —– —— —– ————— —–
DART 46404 45.9N 128.8W 0417Z 0.05M / 0.2FT 20MIN
LANGARA POINT BC 54.2N 133.1W 0424Z 0.20M / 0.7FT 26MIN
DART 46419 48.8N 129.6W 0346Z 0.06M / 0.2FT 12MIN

LAT – LATITUDE (N-NORTH, S-SOUTH)
LON – LONGITUDE (E-EAST, W-WEST)
TIME – TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
AMPL – TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS …NOT… CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
PER – PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

NOTE – DART MEASUREMENTS ARE FROM THE DEEP OCEAN AND THEY
ARE GENERALLY MUCH SMALLER THAN WOULD BE COASTAL
MEASUREMENTS AT SIMILAR LOCATIONS.

EVALUATION

A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG
COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION
SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.

A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE
CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD
COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE
INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST.
TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT
RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI
WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE
CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED
BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH
TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.

THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS
PM HST SAT 27 OCT 2012MESSAGES WILL BE ISSUED HOURLY OR SOONER AS CONDITIONS WARRANT.

WEHW40 PHEB 280804
TSUHWX
HIZ001>003-005>009-012>014-016>021-023>026-281004-
/O.CON.PHEB.TS.W.0001.000000T0000Z-000000T0000Z/

BULLETIN
TSUNAMI MESSAGE NUMBER 6
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
1003 PM HST SAT OCT 27 2012

TO – CIVIL DEFENSE IN THE STATE OF HAWAII

SUBJECT – TSUNAMI WARNING SUPPLEMENT

A TSUNAMI WARNING CONTINUES IN EFFECT FOR THE STATE OF HAWAII.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME – 0504 PM HST 27 OCT 2012
COORDINATES – 52.8 NORTH 131.8 WEST
LOCATION – QUEEN CHARLOTTE ISLANDS REGION
MAGNITUDE – 7.7 MOMENT

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION LAT LON TIME AMPL PER
——————- —– —— —– ————— —–
SITKA AK 57.1N 135.3W 0542Z 0.09M / 0.3FT 30MIN
CRESCENT CITY CA 41.7N 124.2W 0736Z 0.42M / 1.4FT 24MIN
DART 46419 48.8N 129.6W 0344Z 0.07M / 0.2FT 20MIN
ARENA COVE CA 38.9N 123.7W 0633Z 0.32M / 1.1FT 06MIN
WINTER HARBOUR BC 50.5N 128.0W 0413Z 0.23M / 0.8FT 30MIN
DART 46404 45.9N 128.8W 0417Z 0.05M / 0.2FT 20MIN
LANGARA POINT BC 54.2N 133.1W 0424Z 0.20M / 0.7FT 26MIN

LAT – LATITUDE (N-NORTH, S-SOUTH)
LON – LONGITUDE (E-EAST, W-WEST)
TIME – TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
AMPL – TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS …NOT… CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
PER – PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

NOTE – DART MEASUREMENTS ARE FROM THE DEEP OCEAN AND THEY
ARE GENERALLY MUCH SMALLER THAN WOULD BE COASTAL
MEASUREMENTS AT SIMILAR LOCATIONS.

EVALUATION

A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG
COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION
SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.

A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE
CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD
COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE
INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST.
TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT
RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI
WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE
CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED
BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH
TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.

THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS
1028 PM HST SAT 27 OCT 2012

Tsunami warning lifted for Hawaii
State downgraded to tsunami advisory
UPDATED 2:45 AM HST Oct 28, 2012

Hawaii awaits all-clear from tsunami warning

HONOLULU —A tsunami warning for the state of Hawaii was lifted just after 1 a.m. Sunday, according to the Pacific Tsunami Warning Center.

A tsunami warning was issued 7 p.m. Saturday following a 7.7 magnitude quake off of the west coast of Canada near British Columbia Saturday evening at 5:04 p.m.

The quake struck on the Queen Charlotte Islands Region of British Columbia, 452 miles northwest of Vancouver and 164 miles south of Alaska.

A tsunami warning was immediately implemented for the entire western seaboard of the United States and Canada, stretching from Alaska to the California/Mexico border. That was reduced to a regional warning to areas immediately surrounding the earthquake.

The Hawaii alert was issued at 7:09 p.m. after further buoy readings indicated that Hawaii could be impacted.

The tsunami advisory was issued at 12:54 a.m. Sunday.  Sea level changes and strong current may still occur along all coasts that could be a hazard to swimmers and boaters as well as people near the shore at beaches in harbors and marinas.  This threat may continue for several hours.

City officials are suggesting people stay out of the water during the tsunami advisory.

The state will have harbors closed during the tsunami advisory.

State officials also say that three flights were canceled on Oahu and five flights canceled on Maui due to the tsunami warning.

Update at 11: 57 a.m. ET: NHK World TV reports that all tsunami alerts have been lifted.

[H/T Hotair] posted at 11:24 am on April 7, 2011 by Ed Morrissey

As if Japan hadn’t suffered enough over the last few weeks. Another earthquake hit just off the northeastern coast of Honshu near the Miyagi prefecture, a 7.4 magnitude aftershock to last month’s 9.0 catastrophic quake.. Warnings have been issued for a potential six-foot tsunami in an area already battered by massive tsunamis and flooding, not to mention the nuclear crisis to the south:

Japan was rattled by a strong aftershock and tsunami warning Thursday night nearly a month after a devastating earthquake and tsunami flattened the northeastern coast. The Japan meteorological agency issued a tsunami warning for a wave of up to 6 feet (two meters). The warning was issued for a coastal area already torn apart by last month’s tsunami, which is believed to have killed some 25,000 people and has sparked an ongoing crisis at a nuclear power plant.Officials say Thursday’s aftershock was a 7.4-magnitude and hit 25 miles (40 kilometers) under the water and off the coast of Miyagi prefecture. The quake that preceded last month’s tsunami was a 9.0-magnitude.

Reports of damage are so far minimal, but all power was lost in Ichinoseki, and it’s not clear whether that was deliberate or the result of damage to power transmission systems. The government has already issued an evacuation order for the northeastern coast. This time, though, the tsunami is not expected to pose a threat to Hawaii or the US west coast region:

U.S. officials say a 7.4-magnitude earthquake off the coast of Japan is not expected to create a tsunami threat in Hawaii or the West Coast.  Federal agencies say that area includes Hawaii, California, Oregon, Washington, Alaska and British Columbia, Canada.

Initial reports indicated that the government may have evacuated the already-critical Fukushima Daiichi nuclear power station, but a later report backed away from that claim. We’ll keep our eyes on the story as it unfolds, but hopefully the damage will be limited by the earlier destruction.

Japan’s Earthquake Research Committee estimates Friday’s devastating earthquake forced the tectonic plate on which Japan sits to spring eastward by about 20 meters. Sixteen experts including professor emeritus of Tokyo University Katsuyuki Abe analyzed tectonic movements in the focal zone of the Friday quake, at the second ad hoc meeting at the Education and Science Ministry.

The committee also estimates the focal zone may span from waters off the northern Sanriku coast of Tohoku region to part of the Boso Peninsula, Chiba Prefecture near Tokyo. The committee says the zone is about 400 kilometers long and 200 kilometers wide.

The researchers also say the quake caused some parts of Iwate through Fukushima prefectures to sink a maximum of about 75 centimeters. The land remains submerged, even after the tsunami subsided.

EWR monitors Mt Redoubt in Alaska as a result of the eruption of Redoubt in April 2009. This is the seismic trace of the Japan Earthquake and related Pacific rim activity, as recorded on Redoubt webicorder RSO:

Webicorder RSO at Mt Redoubt in Alaska recording the Japan earthquake

The image below is the current RSO seismic webicorder trace for Mt. Redoubt in Alaska. Tremor activity continues in the Rim of Fire, since the Sendhai earthquake went off on the 10th. This image updates in realtime, to give you an idea of the aftershock scenario from a major quake. The challenge for volcanologists is to separate seismic activity of their target (Mt. Redoubt, in this case) from the background activity from unrelated areas. The red lines on the trace are calibration spikes.

Webicorder update is presently offline from AVO
Webicorder RSO_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

Update March 13, 2011: Japan’s Meteorological Agency says the magnitude of Friday’s earthquake that hit the Pacific coast of northeastern Japan was 9.0 instead of 8.8 as earlier announced. The agency made the correction on Sunday morning after analyzing seismic waves and other data. The magnitude is equivalent to that of the 2004 earthquake off Sumatra, Indonesia, which triggered massive tsunamis in the Indian Ocean. The agency says the focal zone of Friday’s quake was about 500 kilometers long and 200 kilometers wide. Destructive movement along the fault continued for more than 5 minutes. The Meteorological Agency says only 4 other quakes in the world have recorded magnitudes of 9 or over. The largest was the magnitude 9.5 quake that hit the Chilean coast in 1960, killing more than 1,600. The quake also triggered tsunamis in Japan, leaving 142 people dead. The 2004 quake off Sumatra registered a magnitude of 9.1. Subsequent giant tsunamis killed more than 200,000 people.

Update March 12, 2011: For detailed technical information, the US Geological Survey pages for this ‘quake are here. The Boston Globe has a good album of photos in their Big Picture blog series.

March 10, 2011: An 8.9 magnitude earthquake has struck Japan today. The epicenter, located just off Japan’s Pacific coast near Sendhai, has triggered a 4 meter high tsunami which is devastating a large area of the adjacent coastline. Tsunami warnings are currently up for the entire North American west coast. A 4.5 magnitude earthquake has just been reported in Hawaii, although officials there don’t know if its associated with the Sendhai quake. Check in from time to time with the NOAA Pacific Tsunami Centre and the Pacific Disaster Center for recent alerts. NHK, the national broadcaster in Japan, is providing updates and contact information in English on NHK World. Please use the link sparingly so that people with a bona-fide need can access the link.

Magnitude 8.9 Earthquake - Japan

WEHW40 PHEB 111133
TSUHWX
HIZ001>003-005>009-012>014-016>021-023>026-111333-
/O.CON.PHEB.TS.W.0001.000000T0000Z-000000T0000Z/
BULLETIN
TSUNAMI MESSAGE NUMBER 7
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
133 AM HST FRI MAR 11 2011
TO – CIVIL DEFENSE IN THE STATE OF HAWAII
SUBJECT – TSUNAMI WARNING SUPPLEMENT
A TSUNAMI WARNING CONTINUES IN EFFECT FOR THE STATE OF HAWAII.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
ORIGIN TIME – 0746 PM HST 10 MAR 2011
COORDINATES – 38.3 NORTH 142.4 EAST
LOCATION – NEAR EAST COAST OF HONSHU JAPAN
MAGNITUDE – 8.9 MOMENT
MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY
GAUGE LOCATION LAT LON TIME AMPL PER
TOSASHIMIZU SHIKOKU 32.8N 133.0E 0946Z 0.84M / 2.8FT 28MIN
ADAK AK 51.9N 176.6W 1034Z 0.35M / 1.2FT 22MIN
YAP FM 9.5N 138.1E 1013Z 0.15M / 0.5FT 88MIN
LEGASPI PH 13.1N 123.8E 1022Z 0.29M / 1.0FT **MIN
MIDWAY 28.2N 177.4W 1028Z 1.56M / 5.1FT 80MIN
DART 21415 50.2N 171.8E 0845Z 0.27M / 0.9FT 52MIN
WAKE US 19.3N 166.6E 0928Z 0.39M / 1.3FT 14MIN
NAHA OKINAWA JP 26.2N 127.7E 0901Z 0.25M / 0.8FT 60MIN
SAIPAN US 15.2N 145.7E 0916Z 0.65M / 2.1FT 30MIN
OMAEZAKI HONSHU JP 34.6N 138.2E 0818Z 1.42M / 4.6FT 56MIN
DART 21419 44.5N 155.7E 0716Z 0.40M / 1.3FT 20MIN
DART 21413 30.5N 152.1E 0659Z 0.76M / 2.5FT 32MIN
HANASAKI HOKKAIDO J 43.3N 145.6E 0657Z 2.79M / 9.2FT 76MIN
DART 21401 42.6N 152.6E 0643Z 0.67M / 2.2FT 40MIN
DART 21418 38.7N 148.7E 0619Z 1.08M / 3.5FT 06MIN
LAT – LATITUDE (N-NORTH, S-SOUTH)
LON – LONGITUDE (E-EAST, W-WEST)
TIME – TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
AMPL – TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS …NOT… CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
PER – PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.
NOTE – DART MEASUREMENTS ARE FROM THE DEEP OCEAN AND THEY
ARE GENERALLY MUCH SMALLER THAN WOULD BE COASTAL
MEASUREMENTS AT SIMILAR LOCATIONS.
EVALUATION
A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.
A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST. TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.
THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS 0307 AM HST FRI 11 MAR 2011 MESSAGES WILL BE ISSUED HOURLY OR SOONER AS CONDITIONS WARRANT.

EWR monitors Mt Redoubt in Alaska as a result of the eruption of Redoubt in April 2009. This is the seismic trace of the Japan Earthquake and related Pacific rim activity, as recorded on Redoubt webicorder:

Webicorder RSO at Mt Redoubt in Alaska recording the Japan earthquake

The image below is the current RSO seismic webicorder trace for Mt. Redoubt in Alaska. Tremor activity continues in the Rim of Fire, since the Sendhai earthquake went off on the 10th. This image updates in realtime, to give you an idea of the aftershock scenario from a major quake. The challenge for volcanologists is to separate seismic activity of their target (Mt. Redoubt, in this case) from the background activity from unrelated areas.

Webicorder update is presently offline from AVO
Webicorder RSO_EHZ_AV 24hr. (refresh for webicorder update – Active trace is the very bottom one).

Update 2010/07/10: There have been some concerns expressed over recent seismic activity at Volcano Katla. There is nothing being reported from the Icelandic Met Office that indicates a concern. Active volcanos tend to have regular periods of seismicity. These recent events are of low magnitude and are not believed to be indicative of imminent eruption of Katla. The earthquake charts on the Met site are updated constantly (near real-time according to the Met Office) and the colours do not indicate severity, only time elapsed since last occurred. Earthquakes greater than magnitude 3 are indicated by a star icon.
_______________________________

Update 2010/04/24: Note: This will be EWR’s last report on the current event sequence at Eyjafjallajökull unless there is a substantial change in events. I invite you to explore the links included throughout this post to develop an understanding of the Eyjafjallajökull event. The Active Monitoring sidebar will continue to list the quicklinks for NORDVULK and the webcams. This post will be added to the general Active Monitoring list for quick access as the EWR blog moves forward.

The bulk of the information presented has been drawn from situation reports of the Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland. Certain links contained below represent specific research efforts of indviduals and are attributed where appropriate. As has been noted in this latest sitrep, the eruption has not ceased and there remains concern about future activity. While Katla is not considered at immediate risk of eruption, the association with Eyjafjallajökull means it will continue to be monitored.

Status report 24 April 2010

from Icelandic Meteorological Office and Institute of Earth Sciences, UofI
Compiled by: MTG / HB
Based on: IES/IMO Inspection flight with aircraft from Ernir at 1600-1700
IMO seismic monitoring
IES/IMO GPS monitoring
IMO river gauges

Eruption plume:
Height( a.s.l): 13000 feet (4 km)
Heading: SW
Colour: Grey

Tephra fallout: Minor (plume dark but no reports of fallout in districts around volcano)
Meltwater: 100-120 m3/s, based on gauge at old Markarfljót bridge and a rough estimate of base flow.

Conditions at eruption site: North crater still active. Mild explosive activity with spatter thrown to 100 m height above crater. Shockwaves occur every few seconds. North of crater a roughly 300 m long and wide depression has been melted out in the last three days. Steam plumes rise from the depression, especially at the margins. This is explained by lava flowing northwards from the crater with the steam rising where lava meets ice.

Seismic tremor: Magnitude similar to what it has been over the last few days.

GPS deformation: Indicates slow subsidence towards the center of the volcano.

Magma flow: Eruption plume: less or equal to 10 tonnes/s.
Lava flow: 10-30 tonnes/s
Total magma flow: 20-40 tonnes/s

Overall assessment: Magma flow rate has remained at similar level over the last few days. Plume activity is gradually declining. Flow of lava is considered to have began around noon on Wednesday 21 April. Timing is based on: a) onset of semi-continuous discharge of meltwater from Gígjökull, b) Observations of steam rising at northern margin of ice cauldon at 1300 on 21 April, and c) a change occurs in fluctuations in tremor amplitude at this time. No signs of melting or meltwater discharge towards south. No signs of termination of eruption.

Eruption update 21 April

Eruption continues with less explosive activity. Eruption rate is inferred to have declined over last few days and now be an order of magnitude smaller than during the initial 72 hours of the eruption. Present eruption rate is estimated to less than 30 m3/s of magma, or 75 tonnes/s , with a large uncertainty.

Eruptive style: The northernmost one of two main craters in the summit caldera is active. Phreatomatic explosive activity occurs with some lava spatter at craters.

Plume height: about 3 km

Tephra dispersal: local towards the south

Meltwater: minor, but what is melted flows down into Markarfljót, no signs of water accumulation in craters

Seismic tremor recorded by the Icelandic Meteorological Office: some fluctuations but mostly stable. Tremor is not decreasing and does not reflect the decline as inferred for the eruption rate.

GPS-measurements: indicate continuing small pressure decrease under the volcano at a similar rate.

Composition of erupted material: Samples collected April 19 show same composition as early in the explosive phase, but fluorine content is higher. Samples collected 19 April have 850 mg/kg (initially it was 25-35 mg/kg). This is due to the change in eruptive style – tephra is now not washed to the same extent by water in the eruptive plume.

Amount of erupted material: Uncertain but on the order of 100 millon cubic meters. Tephra next to craters is 20-30 m thick.

Compiled by: Freysteinn Sigmundsson, Magnús Tumi Guðmundsson, Guðrún Larsen, Níels Óskarsson, Sigurður Reynir Gíslason, Páll Einarsson, Sigrún Hreinsdóttir, Rikke Pedersen, Ármann Höskuldsson, Guðrún Sverrisdóttir, other staff of Institute of Earth Sciences and collaborators.

Radar images acquired yesterday, 20 April, by the Icelandic Coast Guard showed no changes in the size of the cauldron at the eruption site of Eyjafjallajökull, compared with images from 19 April – Eyjólfur Magnússon

20. April 2010: Latest results from GPS stations around Eyjafjallajökull show deflation associated with the eruption. No movements associated with the Katla volcano are presently observed – Benedikt Ófeigsson, Sigrún Hreinsdóttir and Bryndís Brandsdóttir

Eyjafjallajökull frá Hvolsvelli

Screencap 2010/04/17 8:45 EDT of Eyjafjallajökull from Hvolsvelli, Iceland. Mila webcam

Eyjafjallajökull frá Valahnúk

Screencap 2010/04/17 8:45 EDT Eyjafjallajökull from Valahnúk, Iceland. Mila webcam.

Update 2010/04/17:– stable eruption, change in wind conditions

Explosive activity at the eruptive site and seismic tremor continue at a relatively stable rate without a decline overnight. Air space over large part of Europe continues to be closed. Eruption plume loaded with tephra (ash) rises to more than 8 km, with tephra fallout in inhabited areas around the volcano. Over 20 lightning recorded in the eruption plume over a 4 hour period. Overnight wind conditions at the eruptive site change. Steady easterly wind that have prevailed since the onset of the explosive eruptive phase replaced by northerly winds that carry the eruption plume away from the volcano to the south. A MODIS satellite image at 03:41 GMT shows the eruption plume bending from south to east, and a NOAA AVHRR satellite image acquired at 07:01 GMT shows plume heading from the volcano towards the south.

Impact on European Air Travel 2010/04/17 13:25 UTC. Normally the airspace over the United Kingdom, Scandanavia and northern Europe is full of planes.

Ash cloud over Europe April 16, 2010, NASA Earth Observatory photo.

Ash Cloud from Iceland volcano April 15, 2010. NASA Earth Observatory photo

Update 2010/04/16: From Icelandic media sources and the Nordic Volcanic Center, Institute of Earth Sciences [more at link, and check the webcams in the Active Monitoring sidebar.]:

Media: Britain closes airspace as volcanic ash spreads.

The Boston Globe has some good shots in their Big Picture series and here too.

Many good shots here too (this is the Flickr Volcano pool – many recent uploads for Iceland)

Video clips:

New:

Iriya:1:Flickr [Good!], Iriya:2:Flickr [Good, too!], Iriya:3:Flickr
Satli:1:Flickr
Kajarri:1:Flickr
Tackii:1:Flickr, Tackii:2:Flickr
And this one from the Nutter Isles…

Video of the eruption from the air
airflight 2
Ground effect
flooding
local views

GPS measurements from Thorvaldseyri (THEY), south of the Eyjafjallajökull volcano, now show displacement towards north. The station had been moving south since the intrusion activity started in the end of December. This change suggests that an equillibrium has been reached in magma flow in and out of the volcano.
Plot showing the displacement (pdf file – data from Sigrún Hreinsdóttir, runa@hi.is)

Eyjafjallajokull Volcano – GPS Time Series (by Sigrún Hreinsdóttir)

New map of the lava flow from 21 – 24 March 2010 (by Eyjólfur Magnússon, pdf file)

Results from observations flights over the eruption site 21 and 22 March 2010 (pdf file compiled by Eyjólfur Magnússon)

Radar observations at the Eyjafjallajöklull eruption site 14 Apríl 2010 – Eyjólfur Magnússon

Eyjafjallajökull eruption: A new phase started on 14 April 2010
A new phase of the Eyjafjallajökull eruption started around midnight on the 14th of April, where melt penetrated its way to the central crater beneath the glacier. Bad weather makes visual observations difficult, but surveillance flights with radar and temperature sensors will shed light on the new conditions later today.

Eyjafjallajökull eruption: 20 March to present
Compiled by Freysteinn SigmundssonInformation sources: Nordic Volcanological Center, Institute of Earth Sciences; Icelandic Meteorological Office (seismic and hydrological observations) and many others.

20 March, late evening: An eruption begins on Fimmvörðuháls located between the Eyjafjallajökull and Mýrdalsjökull ice caps. The eruption was initially detected visually; a red cloud above eruptive site was seen around 23 GMT. The onset of the eruption was gentle, following a period of weeks and months prior to the eruption of high seismic activity and high crustal deformation rates in the Eyjafjallajökull volcanic system. Seismic tremor begins around 22:30 and rises gently. Seismicity was not enhanced significantly immediately prior to the eruption compared to the weeks prior to the eruption. However, the depth of earthquakes decreases and earthquake propagate from magma upwelling area under Eyjafjallajökull towards the eruptive site.

21 March:
Observations from air in early morning reveal a short (<500 m) NE-SW oriented effusive eruptive fissure with fire fountaining and Hawaiian eruptive style. Fire fountains occur from 10-12 vents, with lava jets reaching up to about 100 m hight. The eruption appeared stable from 4-7 AM when viewed from air. The eruption tremor rose gently until reaching a maximum around 7-8 AM. No further lengthening of the fissure was detected. Lava is limited to immediate surroundings of the eruptive craters (less than few hundred meters). Minor amount of ash falls within few km to the west of the eruption site, carried by easterly winds. No ice melting is occurring as the eruptive fissure is just outside the ice covers of Eyjafjallajökull and Mýrdalsjökull.

22 March:
Initial observations from ground. Activity had focused on a series of closely spaced vents. Prevailing easterly winds lead to maximum scoria accumulation on a linear rim west of the NE-SW oriented fissure. Lava flows (Aa type) towards the Hrunagil canyon with initial view on a spectacular „lava fall“ as molten lava flows off steep cliffs into the canyon.

23 – 31 March:
Steady eruptive activity in initial craters with gradual focusing towards fewer vents. Lava flows towards north into two canyons, Hrunagil and Hvannárgil, with intermittent spectacular „lava falls“ as molten lava flows off steep cliffs into both canyons. Extensive steam plume generation when magma melts snow in front of advancing lava, mostly in the canyons. Two or three plumes observed (one at the eruptive craters, others more pronounced in front of the advancing lava). Meltwater released in batches into rivers in the canyons. Relatively steady eruption tremor recorded by seismometers.

Evening of March 31:
Opening of a new short fissure immediately north of the previous one probably relating to changes at shallow depth in the feeder channel (few hundred meters?). No change in eruption tremor.

31 March – April 6: Activity continues in both the old and new eruptive craters, in a similar manner as before, with lava mostly flowing towards the NE, and pronounced „lava falls“ in Hvannárgil. Last active phase of the of the lava fall into Hrunagil on 31 March.

April 5: Eruption tremor (1-2 Hz frequency band at nearest seismic station Godabunga) begins to decline in a gradual manner.

April 7: Activity has stopped in the original craters of the eruption, and is limited to craters on the new fissure formed on 31 March. Lava flows cover an estimated area of 1.3 square kilometers, with estimated average thickness of 10-20 m. Maximum elevation of scoria craters formed in the eruption is 82 m.

April 9:
After little change in deformation rates during the eruption, timeseries at continuous GPS-stations north of the volcano show sudden change, partly jumping back to pre-eruptive levels. Signals may relate to decreasing pressure in the magma conduit feeding the eruption.

April 11:
Eruption tremor approaches pre-eruptive levels, but visual observation reveal eruptive activity in late afternoon.

April 12: Seismic tremor reaches a minimum – eruption temporarily stops

April 13: Extensive seismic swarm begins around 23:00 under the central part of Eyjafjallajokull.

April 14: Onset of seismic tremor shortly after midnight of increasing amplitude, in association with an eruption from a new vent under the central ice-capped crater of Eyjafjallajokull. The eruption is visually confirmed in early morning – eruption plume rises above Eyjafjallajokull. Meltwater forms a jokulhlaup.

Map of the lava flow on Fimmvörðuháls from 21 March – 7 April 2010 (by Eyjólfur Magnússon, pdf file)
A view from space on the crustal deformation associated with magma intrusion – preceding the March 20th eruption
First interferometric analysis of synthetic aperture radar images acquired by satellites reveal extensive deformation associated with a magmatic intrusion under Eyjafjallajökull preceding the eruption. The deformation signal appear as colour fringes, where each fringe represents a change in range from ground to satellite of 1.5 cm. Extensive deformation is observed both north and south of Eyjafjallajökull. The two images show a large change in range from ground to satellite between September 1999 and March 20, 2010, just prior to the eruption that began around 22:30 GMT. These are the first in a series of interferograms anticipated to be formed showing the course of the eruption.
The interferograms are formed by analysing images from the German TerraSAR-X satellite. The research is a collaborative project between the Nordic Volcanological Center at the Institute of Earth Sciences, University of Iceland, the Technical University of Delft, Netherlands, and the University of Wisconsin-Madison, USA. The initial interferograms have been formed by Andy Hooper at Delft.
Contact persons:  Rikke Pedersen (rikke@hi.is), Martin Hensch (martinh@hi.is), Andy Hooper (a.j.hooper@tudelft.nl), Kurt Feigl (feigl@wisc.edu), Amandine Auriac (ama3@hi.is), Freysteinn Sigmundsson (fs@hi.is)
Terrasar1
Terrasar2

________________________________

Saturday night, Mar 21, 2010, at about 11:30, residents of Fljotshlid, Iceland, noticed an orange flare from the vicinity of the Eyjafjallajökull glacier.

A kilometer long fissure has opened in a passage in Fimmvörduhals, between glaciers Eyjafjallajökull and Mýrdalsjökuland and volcanic magma was erupting up through the fissure.

Scientists say the eruption seems to be small and since it is not under a glacier, the danger is less than it might have been.

An Icelandic Coast Guard aircraft flew over the eruption early this morning. For three hours the plane circled the area and Karl Sigurbjörnsson of RÚV filmed this dramatic video of the eruption (do watch the video – the images are quite spectacular).

The immediate area was evacuated and has been closed to travel. This is a popular tourist area of Iceland, and there is a well-known hiking trail in the vicinity of the eruption. Residents have been allowed to return, but the area remains closed to tourists.

There are concerns that the eruption could spread to beneath the glacier, and there also a watch on Katla (see also Katla Volcano at the Institute of earth Sciences ), a nearby large, presently dormant, volcano. Katla has erupted before, and eruptions under glaciers are especially serious due to rapid melting of large volumes of ice, creating near instant high volume floods.

There have been small earthquakes and seismic activity in the area. Seismic activity in Eyjafjallajökull has been intensive for the past three weeks and most of the earthquakes have been located between 7 and 10 km depth. On March 19th a seismic swarm began east of the top crater, originating between 4 and 7 km depth. The activity migrated eastwards and towards the surface on Saturday, March 20th. At 22:30 GMT a slightly increased tremor was detected on three seismic stations, located within 20 km from the volano’s top crater, and within the next two hours reports on an volcanic eruption were received. (from Icelandic Met Office)

Additional Resources:

Icelandic Met Office
University of Iceland Institute of Earth Sciences, ongoing activity
Katla monitoring
Nordic Volcanological Center
Wattsupwiththat.com: Icelandic fissure eruption triggers worries

The Iceland Review Online is running constant updates as more information comes available.

Observe the Katla Volcano in Iceland from the Katla webcam

Early this morning a massive magnitude 8.8 earthquake hit the coast region of Chile, South America, causing widespread damage to the area between Santiago and Conception, BioBio, Talca and other regions of Chile.

Preliminary photos from Chile are available here and the Boston Globe has good photos here. Note: these are large and there are many – might be a slow load for some visitors.

Located at 36.1° S by 72.6° W and at a preliminary depth estimate of 55 km, the quake burst generated tsunami warnings across the Pacific. Initial observed tsunami height above mean sea was reported to be approximately 8 feet ( 7.7 feet at Talcahuano, Chile (0653Z), 4.2 feet at Valparaiso, Chile (0708Z).

A tsunami is a wave front moving through the ocean (not on top of) at high speed (450km/hr), resulting from the lifting of a large mass of water by the earthquake. On the open ocean, it would be be barely perceptible, but when it approaches land, the depth of the pulse of wave energy causes it to crash into the rising sea floor, lifting and spilling the top of the wave forward on to the land as a surge of high flood water. Since a train of waves is usually created, the danger from a tsunami may exist for several hours as each wave in the train expends its energy on land, with the first wave not necessarily being the highest.

8.8 magnitude earthquake burst along the coast of Chile 2010/02/27. Click on map for more information

… A TSUNAMI IS A SERIES OF WAVES AND THE FIRST WAVE MAY NOT BE THE LARGEST. TSUNAMI WAVE HEIGHTS CANNOT BE PREDICTED AND CAN VARY SIGNIFICANTLY ALONG A COAST DUE TO LOCAL EFFECTS. THE TIME FROM ONE TSUNAMI WAVE TO THE NEXT CAN BE FIVE MINUTES TO AN HOUR, AND THE THREAT CAN CONTINUE FOR MANY HOURS AS MULTIPLE WAVES ARRIVE.

FOR ALL AREAS – WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURS AFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOT OCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUME THE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CAN CONTINUE FOR SEVERAL HOURS DUE TO RAPID CURRENTS. AS LOCAL CONDITIONS CAN CAUSE A WIDE VARIATION IN TSUNAMI WAVE ACTION THE ALL CLEAR DETERMINATION MUST BE MADE BY LOCAL AUTHORITIES.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES AT FORECAST POINTS WITHIN THE WARNING AND WATCH AREAS ARE GIVEN BELOW. ACTUAL ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN SUCCESSIVE WAVES CAN BE FIVE MINUTES TO ONE HOUR.

The Pacific Tsunami Warning Center has issued a tsunami warning for Hawai’i.

A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.
[…]
THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS 1119 AM HST SAT 27 FEB 2010 (Hawaii is 10 hours behind Eastern Standard Time).

Update: Hawai’i went into full disaster preparedness mode. They closed coastal roads, the US Navy moved ships out to sea from Pearl Harbour, as did many owners of small boats. The PTC anticipated that wave heights could be as high as 10 feet. All coastal areas of Hawaii were believed to be at risk. In the end, wave heights were less than a metre generally.

The two images below are screencaps at about 4:45ff HST of the draw down from the arrival of the first tsunami wave in Hilo Bay, Hawaii. The little beach on the left was flooded on the fill from the first wave. The second picture is a screencap of the fill from the first tsunami wave. As of this posting there have been 4 draws and fills.

Hilo Bay, HI at full draw down on arrival of first tsunami wave

First tusnami fill after previous drawdown. Abt a foot above tide level

View live video feed from KGMB/KHNL Hawaii and from KHON.[now closed -Ed.]

Islands of the Marquesas did report a 6 foot wave coming ashore, and New Zealand reported a 6 foot surge in some areas.

This is the second tsunami warning issued in the past week. On February 23, 2010, a magnitude 7 earthquake struck the Ryukyu Islands in Japan, and on February 18, 2010, a deep magnitude 6.8 quake struck the China/Russian border on the Sea of Japan. Thus far, there have been more than 56 aftershocks greated than magnitude 5 in Chile.

While earthquakes are common around the Pacifc Rim, most have magnitude of 5 or less, and generally don’t cause significant damage or tsunamis.

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