Vikings Volcanic Activity Thread

[Guest Shetland Coastie]

UPDATE - SAUDI ARABIA

Saudi Authorities have ordered the evacuation of some 60,000 people from Al Ais and surrounding villages, Saudi media are reporting. Warning sirenes have been heard in affected areas and advice on what to do is being broadcast on TV. All schools in the area have now been closed.

Saudi Geological Survey (SGS) Scientists have conducted an overflight of the area and confirm the existence of a large crack which has opened in the ground near Harrah Al Shaqah.

[karyo]

Interesting news! I wonder whether there will be a massive explosion or just lava flow.

I hope everybody is safe.

Karyo

[Guest Shetland Coastie]

UPDATE - REDOUBT

Continuing in much the same vein as the previous few weeks. In answer to fozis question earlier about the size of the lava dome, the last time AVO did measurements was a several weeks back and at that time it measured 500m wide, 700m long and 150m high. However, they have just been to the volcano for some field work the other day and they should have the data ready for publication next week, including a new measurement of its size. One thing they did say though was that the volume of the lava dome now is equivalent to 11 Great Pyramids!

[Guest Shetland Coastie]

UPDATE - SAUDI ARABIA

The picture is becoming slightly clearer with the location pinned down to the Harrat Lunayyir volcanic field. All the recent earthquakes have been located beneath this feature with yesterdays big one, Mag 5.7 located directly below the volcano. All the earthquakes have been located in the upper 10km of the crust, so fairly shallow.

Harrat Lunayyir is a large volcanic field containing approx 50 cinder cones of varying size. There are large basaltic lava flows extending from the area, some of which have reached the Red Sea, some 35m away. The last known eruption was in approx 1000AD. This field tends to be effusive in nature although explosive events are not impossible.

Saudi authorities seem to be taking the threat of something volcanic happening seriously and have now extended the evacuation zone to some 40km from the volcano.

Satellite picture below of the field clearly showing the extensive lava flows:

Edited May 21, 2009 by Shetland Coastie

[MR EXTREMES]

UPDATE - SAUDI ARABIA

The picture is becoming slightly clearer with the location pinned down to the Harrat Lunayyir volcanic field. All the recent earthquakes have been located beneath this feature with yesterdays big one, Mag 5.7 located directly below the volcano. All the earthquakes have been located in the upper 10km of the crust, so fairly shallow.

Harrat Lunayyir is a large volcanic field containing approx 50 cinder cones of varying size. There are large basaltic lava flows extending from the area, some of which have reached the Red Sea, some 35m away. The last known eruption was in approx 1000AD. This field tends to be effusive in nature although explosive events are not impossible.

Saudi authorities seem to be taking the threat of something volcanic happening seriously and have now extended the evacuation zone to some 40km from the volcano.

Satellite picture below of the field clearly showing the extensive lava flows:

this seems to be fairly serious event is it possible a pretty big eruption could come from this?.

cheers love this thread awsome

[Louby]

tis awesome BB innit

Bob, do you know when the last know eruption was in that area?

[The PIT]

tis awesome BB innit

Bob, do you know when the last know eruption was in that area?

10AD or earlier according too http://www.volcano.si.edu/world/volcano.cfm?vnum=0301-04-

[MR EXTREMES]

so really this could be a fairly fearsome eruption.

[Guest Shetland Coastie]

tis awesome BB innit

Bob, do you know when the last know eruption was in that area?

1000AD (i.e 10th century) according to the Global Volcanism Program

GVP

I think its unlikely to be major badboy, in terms of explosive activity, it could be major in terms of lava effused however.

[Louby]

10AD or earlier according too http://www.volcano.si.edu/world/volcano.cfm?vnum=0301-04-

Ta

This year seems to be more active on the volcanic and earthquake from, do you have any thoughts on this anyone?

[Guest Shetland Coastie]

UPDATE - ALASKA

REDOUBT - ALERT STATE = ORANGE:

Continuing much as before with elevated but steady seismicity punctuated by occasionally large amplitude quakes. The very large quakes observed on the webicorder are actually regional tectonic events being picked up by the equipment at Redoubt. Camera views are obscured by poor weather today.

Summit webicorder

VENIAMINOF - ALERT STATE = YELLOW:

Elevated seismicity continues at the volcano but there is no other evidence at the moment to suggest anything out of the ordinary.

Edited May 21, 2009 by Shetland Coastie

[Guest Shetland Coastie]

Ta

This year seems to be more active on the volcanic and earthquake from, do you have any thoughts on this anyone?

Hi Loubs.

Thats a question thats cropped up a few times on here recently. I did ask the folks at the GVP and they are fairly certain that whilst we may have seen an upswing in activity over the last 6 months or so, this is nothing out of the ordinary and over the piece, these things even themselves out.

I asked the same question of Dr. Erik Klemetti, a Geologist at University of California, who said much the same thing but, he said he would gather together some data to see if that is the case or not, so Im hoping to hear back from him soon.

[LadyPakal]

Re: the Saudi activity, the lava tends to be of a similar type to the Hawaiian volcanoes, thin & runny (for want of better words) rather than thick & explosive. It creates the lava fields you see in that satellite image by erupting and spreading out, a bit like golden syrup (only hotter!). That's not to say it won't go bang - you never know with these things.

[Louby]

Hi Loubs.

Thats a question thats cropped up a few times on here recently. I did ask the folks at the GVP and they are fairly certain that whilst we may have seen an upswing in activity over the last 6 months or so, this is nothing out of the ordinary and over the piece, these things even themselves out.

I asked the same question of Dr. Erik Klemetti, a Geologist at University of California, who said much the same thing but, he said he would gather together some data to see if that is the case or not, so Im hoping to hear back from him soon.

B)

Will be very interested to hear the result :o Would you post them if you hear back from him?

[RedShift]

quote name='LadyPakal' date='21 May 2009, 06:08 PM' post='1530527']

Re: the Saudi activity, the lava tends to be of a similar type to the Hawaiian volcanoes, thin & runny (for want of better words) rather than thick & explosive. It creates the lava fields you see in that satellite image by erupting and spreading out, a bit like golden syrup (only hotter!). That's not to say it won't go bang - you never know with these things.

[Guest Shetland Coastie]

UPDATE - SAUDI ARABIA

According to SGS the ongoing activity in western Saudi is highly likely to be volcanic in origin. As well as the continuing elevated seismicity (although not as elevated as yesterday) SGS has confirmed that volcanic gasses are being emitted from the ground in the area of Harrat Lunayyir. This suggests magma moving towards the surface which is de-gassing as it does so.

Several thousand people have now been evacuated from the area and relocated to Yanbu and Madinah. The evacuations are ongoing. The area around Al Ais was today visited by the Governor of Al Madinah Province, Prince Abdul Aziz bin Majed who sought to reassure the locals that every precaution was being taken. He later held an emergency meeting at the Royal Commission in Yanbu to discuss emergency plans to deal with any potential eruption.

Edited May 22, 2009 by Shetland Coastie

[Guest Shetland Coastie]

UPDATE - ALASKA

Nothing much to report on the two Alaskan volcanos at heightened alert, Redoubt and Veniaminof.

Activity remains pretty much at the same level at Redoubt with elevated but fairly steady seismicity. The seismic network at Veniaminof has recorded almost continuous volcanic tremor all this week. Despite this, there are no outward signs of anything unusual at the volcano.

Edited May 23, 2009 by Shetland Coastie

[Guest Shetland Coastie]

ACTIVITY ROUND-UP - KAMCHATKA & NORTHERN KURILES - RUSSIAN FAR EAST

ALERT STATES:

ORANGE:SHEVELUCH

YELLOW:KLYUCHEVSKOY, KORYAKSKY, BEZYMIANNIY, KARIMSKY, EBEKO

GREEN:TOLBACHIK PLOSKY, KIZIMEN, AVACHINSKY, GORELY, MUTNOVSKY, CHIKURACHKI & ALAID

SHEVELUCH: A new viscous lava flow is being effused from the lava dome. Seismicity has been at background levels all week, with occasional ash plumes up to 5km and some vigorous steam/gas activity. Ash explosions up to 10km could occur at any time.

KLYUCHEVSKOY: Seismic activity has weakened over the past week with occasional weak tremor events and some moderate fumarolic activity.

KORYAKSKY: Fairly quiet with seismicity at or near background levels, however, there was some fairly strong fumarolic activity.

KARYMSKY: Seismic activity was above background levels for much of the week with occasional bouts of weak volcanic tremor, perhaps associated with minor ash production.

BEZYMIANNIY: Seismicity was at background levels for much of the week, with weak fumarolic activity. However, on 20 May, a thermal anomaly was noted in satellite imagery and growth of the lava dome continues.

EBEKO: Strong gas & steam emissions (some with ash content) observed at the volcano. KVERT warn of the danger of sudden ash explosions up to 3.5km.

[Guest Shetland Coastie]

ACTIVITY ROUND UP - CASCADES RANGE AND ASSOCIATED VOLCANOS - USA

This round-up includes the following North American volcanos:

MOUNT BAKER, GLACIER PEAK, MOUNT RAINIER, MOUNT ST.HELENS, MOUNT ADAMS, MOUNT HOOD, MOUNT JEFFERSON, THREE SISTERS, NEWBERRY, CRATER LAKE, MEDICINE LAKE, MOUNT SHASTA & LASSEN PEAK.

According to CVO (Cascades Volcano Observatory) seismicity at all the above volcanos is at normal background levels and the alert state for them all remains at GREEN.

There were occasional rumblings at Mount St. Helens but this is likely associated with movement of the glacier within the crater. USGS field crews were out on the volcano on Thursday carrying out repairs to monitoring equipment and noticed nothing unusual. St. Helens has now been quiet since the lava dome growth abruptly halted on June 10th 2008.

[Guest Shetland Coastie]

ACTIVITY ROUND UP - HAWAII

KILAUEA - alert state - ORANGE:

A glowing pool of molten lava is present at the Halema'uma'u vent in the summit crater. S02 emissions from this vent remain elevated with the most recent measurements showing an emission rate of some 1,200 tonnes per day (as against a normal background rate of 140 tonnes/day). Seismic activity is classified as 'moderate.'

At the east rift vent and flow field, magma is being degassed through the Pu'u O'o crater and erupting from vents further east. Lava being erupted through the Thanksgiving Eve Breakout (TEB) continues to flow through lava tubes to two ocean entry points to the west of Kalapana at Waikupanaha and Kupapa'u. S02 emissions from this area of the volcano are below background levels at some 1400 tonnes/day as against the background rate of 1700 tonnes/day.

MAUNA LOA - alert state - YELLOW:

Activity is fairly low at the volcano. The only thing of note is that the volcano is extending, lengthwise (Mauna Loa is a large shield volcano i.e. low and slightly rounded like a shield so tends to grow sideways rather than upwards) slightly faster, but it is thought this is connected slippage associated with faults beneath the east flank, rather than the injection of new magma into the volcano. Gas measurements and temps within fumaroles remain at normal levels and seismic activity is also fairly low.

HUALALAI - alert state - GREEN:

Not as well known as the two famous volcanos, Hualalai has been historically very active, the last time in 1801. Whilst earthquake activity has been low and many homes and indeed Keahole airport has been built near the volcano, there was an intense swarm of earthquakes in 1929 that were very likely associated with magma rising to near the surface. For this reason, HVO considers the volcano to be highly dangerous and are confident another eruption can be expected within the next 100 years.

LO'IHI:

Lo'Ihi (Hawaiian for 'long') is a submarine seamount which lies some 30 km south of Kilauea and some 969m below sea level. It is the latest product of the volcanic hotspot which has given birth to the Hawaiian Islands and will likely be the next to break the surface. It has been the centre of some intense earthquake swarms although no eruptions have been observed. The most recent earthquake swarm was in 2005 and the seamount has now been visited by scientists from the University of Hawaii who found eveidence of an eruption in 1996 (associated with an intense earthquake swarm) and they confirm that this is indeed a young and very active volcano.

The map below shows its location in relation to the main Hawaiian island:

Edited May 23, 2009 by Shetland Coastie

[Guest Shetland Coastie]

ACTIVITY ROUND UP - YELLOWSTONE CALDERA - USA

Alert state - GREEN

YVO states activity at Yellowstone was at or near normal for the month of April. 292 earthquakes were recorded, the largest being Mag 2.7 on 28 April. There were 3 earthquake swarms. The first was located some 4 miles NW of west Yellowstone, consisted of some 62 events from Mag 1.6 - 0.3 between 13 - 18 April. The second occured between 17-24 April and was located some 7 miles NW of west Yellowstone and consisted of some 111 events of between Mag 2.3 to 0.8. Finally the third swarm was located some 11 miles NE of Old Faithful and was of 19 events of Mag 2.7 - 0.5 all on 29 April. YVO regards this activity as 'relatively normal.'

Ground Deformation equipment shows that the caldera continues to inflate. The area of greatest inflation is the NE of the caldera, which has risen some 23cms since 2004. This uplift is being constantly monitored as it may be indiciative of the magma chamber below being filled with magma. However, inflation and indeed deflation of this huge caldera is not, in itself, unusual.

[Guest Shetland Coastie]

ACTIVITY ROUND UP - LONG VALLEY CALDERA - EAST/CENTRAL CALIFORNIA - USA

Long Valley is a large caldera, measuring some 15 x 30km situated to the east side of the Sierra Nevada in east/central California. The caldera was formed by a massive eruption some 760,000 years ago. A number of smaller eruptions have occurred since, the last being some 250 years ago from Mono Lake. The caldera is still very active. It continually emits fairly high levels of C02 (some 50-100 tonnes/day) and has a resurgent lava dome, which has increased in height by some 80cms since the late 1970's. This growth halted in 2003 and the dome remains fairly stable.

Normal sesimic activity is an average of 5 small earthquakes per day. Over the past few days, however, this has increased somewhat, with 21 earthquakes being recored on 21 May, the largest being Mag 2.1.

Current alert state is GREEN.

[Guest Shetland Coastie]

UPDATE - SAUDI ARABIA

It is now becoming increasingly aparrent that the Saudi authorities are taking the possibility of a volcanic eruption in western Saudi very seriously. It now transpires that the entire population of the areas largest town, Al Ais, some 26,000 people have now been evacuated. All the main roads into the town from Madinah, Yanbu and Umluj have been closed and are being guarded by the Saudi military.

Civil Defence teams have been placed on high alert and the Royal Saudi Air Force has flown specialist equipment and a further 120 Civil defence officers into the area in case of a major emergency.

Latest reports today suggest seismic activity has declined slightly and there have been no further reports of gas emissions, although an overflight by SGS scientists has observed two large cracks in the ground near the epicente of the eartquakes at Harrat al Shaqah, one measures 3km long, the other is some 700m in length.

Edited May 23, 2009 by Shetland Coastie

[Guest Shetland Coastie]

UPDATE - REDOUBT

Much as before although my interpretation of the webicorder is we are starting to see these repetitive, low amplitude earthquakes appearing which are indicative of the lava dome becoming destabilised. Good close-up view of the lava dome in the Hut webcam:

Hut webcam

Summit webicorder

[Guest Shetland Coastie]

UPDATE - SAUDI ARABIA

After the alarm and indeed in some places, near-panic, caused by the strong tremors last week. Things seem, on the face of it, to be settling down again, with tremors still continuing but at a much lower intensity and much less frequently than before.

There is even talk of allowing those evacuated from the area back to their homes in the next couple of days. Whilst this is obviously good news, one obviosuly has to be very careful where possible volcanic activity is concerned, it can be very unpredictable, particularly in an area where it is infrequent and the historical records of volcanic activity are poor.