Volcano Watch 2014

originally posted by: Darkblade71
M5.7 - 116km SSE of Akureyri, Iceland 2014-08-26 01:26:08 UTC
earthquake.usgs.gov...

Another big one.

Hmm not sure about who to believe
IMO only have
20140826 012606, 64.67715, -17.47328, 6.191km, 4.13M, 3.96ML hraun.vedur.is...

GFZ quite high too 5.3

3.96ML = 5.7Mw????????

previously the other USGS 5's on the 24th were listed as 5M's on IMO too, maybe they haven't got around to looking into it yet

Another great read on the Iceland situation ..... only in Italian, and great work !

Finally found a map indicating Map location of all those Icelandic names in the quake reports

Today's update makes note that:

There have been no signs of harmonic tremor.

According to USGS:

Harmonic tremor describes continuous rhythmic earthquakes that can be detected by seismographs. Harmonic tremors often precede or accompany volcanic eruptions.

So, I'm not saying that we're out of the woods with this, but the threat does not appear to be imminent.

Bishop

a reply to: Bishop2199

Yep, so far so good!

Although I would love to see a volcanic event, I don't want to see one.

I know how bad it would effect Europe is it were to go into a major eruption,
so I don't want that to happen, but I also love earth sciences,
and the watcher in me wants to see something happen.

*sigh*

A double edged sword here in hoping it does not erupt,
but watching and waiting to see something spectacular occur.

Taken from your link:

There are no indications that the intensity of the activity declining.
The following three scenarios are still considered most likely:

The migration of magma could stop, accompanied by a gradual reduction in seismic activity.

The dike could reach the surface of the crust, starting an eruption.
In this scenario, it is most likely that the eruption would be near the northern tip of the dyke. This would most likely produce an effusive lava eruption with limited explosive, ash-producing activity.

An alternate scenario would be the dyke reaching the surface where a significant part, or all, of the fissure is beneath the glacier. This would most likely produce a flood in Jökulsá á Fjöllum and perhaps explosive, ash-producing activity.

Other scenarios cannot be excluded. For example, an eruption inside the Bárðarbunga caldera is possible but presently considered to be less likely.

Still looks like anything could happen.

a reply to: Darkblade71

The dyke beneath Dyngjujökull is now thought to be close to 40 km long. Modeling of GPS data indicates that about 50 million cubic meters of magma have added to the volume in the last 24 hours.

Source

Although there are no harmonic tremors, it still appears to be alive. That's a lot of additional material in the last day.

I'm with you. I would love to see something happen to experience it, but I also don't look forward to all the lives that would be disrupted.

Bishop

a reply to: egoli
Great new links both the Italian site & the map. Thanks for posting them.

The Centroid Moment Tensor from the Mag 5.7 located +/- 6 km below the north rim of the Bardarbunga caldera is showing north-south extension. (normal faulting)

Here is Geofon's moment tensor for the quake.

This quake could be further indicating ring-faulting due to caldera subsidance.

There is a new post at Wired's Eruptions blog speculating on what could happen if the dike intrusion intersects Askja's magma "chamber".

["chamber" is in quotes because, in reality, it's not a big cavern filled with liquid magma, but more like a blob of sponge with small tendrils of melt (crystal mush).]

Update on Status

There are no indications that the intensity of the activity declining. Currently, three scenarios are considered most likely:

1) The migration of magma could stop, attended by a gradual reduction in seismic activity.
2) The dike could reach the surface of the crust, starting an eruption. In this scenario, it is most likely that the eruption would be near the northern tip of the dike. This would most likely produce an effusive lava eruption with limited explosive, ash-producing activity.
3) An alternate scenario would be the dike reaching the surface where a significant part, or all, of the fissure is beneath the glacier. This would most likely produce a flood in Jökulsá á Fjöllum and perhaps explosive, ash-producing activity. Other scenarios cannot be excluded. For example, an eruption inside the Bárdarbunga caldera is possible but at present considered to be less likely.

Here's the latest:

Just under 900 earthquakes have been detected by the network since midnight, somewhat fewer than at the same time yesterday. The intrusive dike is now about 40 km long. Most of the activity has been near the edge of the glacier. An earthquake M4.6 (EMSC M4.4) occurred at 11:56. Reports were received from Akureyri (a town in northern Iceland) that the earthquake was found there. The earthquakes are mostly on similar depth as before, i.e. 8-12 km. A few were larger than M3. Few earthquakes were located in the Bárðarbunga caldera today.

Source

Things seem to be quieting down a bit.

Bishop

Commentor at VolcanoCafe is noting that the earthquakes at the rift tip look like they may be trending deeper which opens the possibility of mantle involvement in a rifting type eruption if it happens meaning it could go on for quite a while.

a reply to: egoli

sounds great but it won't open for me, keeps telling me to instal Adobe Flash Player , which I already have.
any chance there is a pdf version?

a reply to: muzzy

Those graphs are really great. I wonder if you would consider adding the location of the mid-Atlantic ridge? I keep trying to see it in my mind and wonder just how it plays into what might happen next.

a reply to: aboutface

Thanks. The maps only show an small area at the north end of Vatnajökull glacier under which lies Bárðarbunga volcano, I'm showing an area approx. 62kn West East x 55 km North South. The island of Iceland sits on the Mid Atlantic Ridge, its the only landmass above water on it, the MA Ridge isn't just a line in a map like a fault line, as it passes through Iceland its fractured into hundreds of fault lines.
Yes, whatever happens on the Mid-Atlantic Ridge effects Iceland/these volcanoes, Iceland is part of the Mid-Atlantic Ridge.

Here's a quake timelapse. Watch how they work their way around Bardarbunga's caldera. Possible evidence of ringfaulting?

a reply to: egoli

Got it. But not on Adobe.
there is a i-pad version here
atlas.lmi.is...

has the names of topographical stuff, not just towns
I was trying to find the name of that small cone to the north west of the swarm, the round one, its called Trolladyngja

I spent an hour this morning searching for a decent topographical map of Iceland, just couldn't find anything detailed.
This will do, I'll put some names on the Animation, I'm doing a new one, old style, with my coloured orbs.

a reply to: ketsuko

yeah well done, can't see the size of the video in MB but I tried my animation as a vid and it was bigger than the animated GIF.
Bit blurry, see what I mean about the maps, not much detail
1897 frames, geez someone has more time on their hand than I do!

What I saw was near the end, how the quakes backed up on themselves, hovering around the edge of the glacier

are those the last ones happening deeper I wonder?
did that happen on the last hesitation back on 23rd?, then it burst forth north in another direction.

Iceland another 5.2 8 minutes ago 1.4km
baering.github.io...

USGS now saying 5.6

earthquakes track is getting pretty close to Askja volcano !
Now don't panic folks, the first 2 hours shown on the second pic are only preliminary ie it hasn't been checked by humans yet, give it an hour or two for the scientists to wake up over there and have a look.
Because the IMO maps don't include Askja I'm not sure if this pattern is normal for preliminary (ie scattered all over the place)
I wonder if they have the same problem as I do the freakin' maps won't fit on a computer screen at 5km resolution

earthquakes for 26th final

Incl Askja area, first 2 hours of 27th

right click "view image" for full size

I've just about done the coloured aninated GIF, will post it here shortly. It won't include the last 2 hours though.

They just had another 5.0 very shallow. Don't have a link.

sorry still trying to figure the new set up.