The pain filled issue with Ischia

Photograph by Giovanni Mattera. Castle Aragonese seen from Ischia. The castle is sitting ontop of a resurgent dome plug from a flanking vent.

The World’s most ill begotten piece of real estate – Part III

The Chinese have a saying, “May you live in interesting times”. And it is in no way a friendly thing to say; on the contrary it is a rather magnificent curse. In Naples people live all their lives in interesting times. If it was not enough with being the poorest city in Italy, they also have to contend with the Camorra (local mafia), drug-wars, corrupt politicians, strikes and general civil unrest. To top it off even further they have built their city on top, or around, no less than 3 active super volcanoes. Could the times get more interesting than that? Well you could add large earthquakes and tsunamis to the list.

Ischia, or more correctly Monte Epomeo, started it’s activity about 350 000 years ago. Technically it is of the complex volcano type. During the first 300 000 years it grew and developed a large edifice paired with an over-sized volcanic sub-structure.

56 000 years ago the volcano had reached the critical level where the edifice was too large and heavy to be sustained on top of the very large magma chamber. The eruption probably started as a very large VEI-6 eruption that emptied out the magma chamber sufficiently for the roof to collapse. And since Ischia is an Island it then got messy as the ocean roared down into the open magma chamber. The ensuing VEI-7 explosion created the Green Tuff Ignimbrite. This Green Tuff Ignimbrite should not be confused with the even larger Pantelleria Green Tuff (Italy is rather interesting…) that covers most of the Mediterranean area.

Photograph showing Sant Angelo D’Ischia, another resurgent dome from a flanking vent.

After the eruption the Island was completely gone. As far as is known a 23 000 year long period of dormancy followed, but there might have been minor subsurface eruptions that helped to start healing the roof of the volcanic chamber system.

33 000 (Ar/K-dating) years ago a new phase started where the volcano had frequent effusive eruptions that helped to weld the tuff together healing the roof of the magma chamber along the entire 10 kilometer wide caldera.

28 000 years ago things started to get really interesting. By then the roof above the chamber was sufficiently structurally sound to hold for the increasing pressure inside the chamber. That caused the entire roof to be pushed upwards.

Most of the readers in here are familiar with the concept of resurgent lava domes. We have all seen them being pushed out of craters like odd plugs. For those interested in seeing the phenomenon I recommend Soufriere Hills at Montserrat. Thing is though that it is normally smaller craters that suffer from this rather dangerous condition.

The island of Ischia photographed from Castle Aragonese. The mountain area in the background on the island is Monte Epomeo, a resurgent dome formed as the caldera floor is lifted up above the caldera rim. Here be Dragons.

Problem here is that Monte Epomeo is a super volcano, and as such does things in super-size. And if you super-size a resurgent dome, then you have an entire caldera floor rising upwards. Just imagine the pressure needed to push up a ten kilometer wide plug 900 meters in 28 000 years.

I know, we are only talking about 3.2 millimeters per year on average, but it still requires rather stunning amounts of power. The uplift is though larger than that, the reason for that being failures in the resurgent dome with rock-slides and sector failures of the dome as it started to stick up above the caldera rim. 5 600 years ago the dome passed the rim. During the push up phase the dome had also dragged the caldera rim with it above surface, and around the island an elevated area has been created by the pressure. So, a lot of pressure has gone also into moving parts that technically are not a part of the resurgent dome.

Eruptive and other behaviors

The most common type of eruption at Ischia is smaller eruptions taking place between the resurgent dome and the caldera rim. There are quite literally hundreds of fissures, cones, and other volcanic vent types encircling the dome. These eruptions normally follow episodes of rapid surging (uplift) of the dome.

There are two more dangers on top of the island caused by the resurgent dome. The first one is quite simply sector collapses, landslides and rock-falls as the brittle welded tuff suffers structural failure. Some of these slides and rock-falls have reached as far as the coast line.

General volcanic map of Ischia showing major features of the volcano. Click for larger image.

The more dangerous version of failure is the lateral flank eruption. That happens as magma pushes upwards and builds up tremendous pressure and swelling of the side of the dome and the side of the caldera rim. Think Mount Saint Helens here and you get the picture. This causes a large pyroclastic flow going laterally over the island until it reaches the coast, then it will continue over the water. If it happens in the wrong direction it will hit inhabited land.

Critical lateral collapse of the resurgent dome towards the Bay of Naples.

During the last 12 000 years there has also been 3 sub-surface collapses of the island causing massive debris flows running out into the Tyrrhenian Sea. And there are several spots along the coast line where parts of the Island have calved off into the ocean. When this happens large tsunamis will race into the Bay of Naples destroying any part not high up. The latest known widespread tsunami in the area is known to have happened 800BC according to written records.

Debris flow from a sub surface failure of the shelf around the island. The surge direction caused a large tsunami to go into the Bay of Naples.

In the end though it is probably the super part of Monte Epomeo that interests people more than anything else. Because however you look at it, there is between 70 and 210 cubic kilometers (conservative estimate) of magma in various grades of fractionalization down under that ever uplifting plug. The volcano also has an ample supply of fresh water to drive up the pressure for a larger eruption, and when that happens the same thing that happened to Krakatoa and Santorini will happen to Ischia. And as with the two more famous volcanoes, it has happened before.

Current status of Ischia

Even though Ischia is currently not showing any sign of erupting other than the steady uplift she is deemed by INGVs Director Guido Bertolaso to be the most likely volcano to erupt due to the rapid buildup of magma that they have recorded. Bertolaso even went so far as stating “if I had to say which is the volcano with the most loaded gun barrel, I’d say it’s not Vesuvius but the island of Ischia”. He though went on to state that no eruption is imminent. This becomes evident if one looks at the lack of heightened volcanic tremor, and minimal amount of magmatic earthquakes.

Risks of Ischia

The risks are roughly discussed below in the order of likelihood. Ischia is the volcano most likely to have a large eruption in the Naples area. One should though remember that it is most likely to have a normal VEI-1 to VEI-4 eruption when it erupts next. This would mainly affect the 60 000 residents on the island, and the same amount of tourists.

Rock falls, dome failures and landslides from Monte Epomeo is also fairly likely to happen in the foreseeable future due to the resurgent dome uplifting. This will also only affect the local residents and tourists.

Large landslides either at the coast, or out on the elevated shelf that surround the island is fairly likely to happen within the next few thousand years as the pressure building up raises the land up and weakens the structure of the flanks. When this happen large tsunami waves will hit the Bay of Naples causing widespread destruction. This is also the risk that is hardest to predict and mitigate.

In the same timeframe there could be another partial dome collapse causing a Mount Saint Helens style eruption. This would destroy all buildings on the island, cook the inhabitants, and depending on the direction of the pyroclastic surge hit areas far into the Bay of Naples. I do not think we need to contemplate the effects of a hydro-magmatic eruption at the VEI-7 scale. I would only like to point out that Ischia is the most likely candidate of having such an eruption in the neighbourhood of Naples. Right now there is nothing pointing towards it happening within the next millennia, but in the end it is likely to happen within the next ten millennia due to catastrophic failure in the resurgent dome.

Ischia early in the morning. The sleeping Dragon rests calmly.

Ischia is more likely to kill people than any other volcano. This is due to the absolute lack of places to run to quickly since it is a heavily populated island, and that half of the inhabitants at any given time are tourists not knowing where to go. So even the smallest event will get messy, best case scenario is probably a VEI-1 eruption with clear precursors for INGV to order a complete evacuation. Anyhow, anything interesting happening at Ischia is more likely to kill thousands up to millions than any of it’s siblings due to it having more modes of operation.

Not only do we live in interesting times, now we have an inflamed Ischia.

Short addendum on the Turkish quake

There has been an earthquake just south Antalya. It ranged between 5.8 and 6.2, figures are going to be revised. The distance from Antalya, and depth is very likely to cause damages to houses and fatalities.

The associated beach ball has a rather odd look to it. But this is also likely to change. The EMSC-CSEM site has gone down due to pressure from people trying to get info. USGS is open for business. Here is a link to their beach ball and other technical data.

http://earthquake.usgs.gov/earthquakes/eqarchives/fm/neic_b000ac4h_fmt.php

Oddball beach ball of Turkey.

CARL

About these ads

255 thoughts on “The pain filled issue with Ischia

  1. And here is the answer to the age old conundrum… How does an inverted caldera look like?

  2. The major structure in the vic of the quake is an oceanic spreading center/continental rift. (it makes the transition from one to the other in that region.) The feature seems to be pretty inactive as spreading centers go. But the quake, is strike-slip. This is more characteristic of transform faults. The Agean Plate is to the west, and the African plate is driving under it along the arc that makes Crete and eventually feeds Santorini. The area of the quake is the eastern boundary of that plate.

    Yeah… pretty odd. Dunno what it’s up to.

    • If you look at the volcanic feature map up above you can see the outline of it.
      The eruption stars are the outline. It is also visible on the pics.
      I was a bit stumped when I read the papers, I didn’t think they came at that size.

      • Yep… alarm. If it were dispute, it would have been preceded by “that’s” or “it is.”

        “Crap” is one of those utility words where the meaning is inferred by it’s placement or intonation in a sentence. I’ll not mention the other word that has much more utility, but only acknowledge that it exists.

        While many of us here are sort of “adults,” others may pass by and I would not want to invoke any content filters.

  3. BTW… it’s still raining here. When it’s all said and done, it will probably be up into the 18 to 28 inch range (over three days)

    This line has echo tops of about 40 to 45 thousand feet. (the mean cumulonimbus variety)

    • I guess we had it coming. The last two Hurricane seasons have been paltry, despite what NHC may wish to say. Hurricanes are heat engines, pulling energy off of the water and shuttling it to the northern Latitudes. I think these storms are just the Gulf’s way of shedding energy since no healthy tropical systems have been by to do it.

      • Widespread heavy rain and thunderstorms capable of producing tornadoes are moving into southern Alabama.

        • Tornado Warning for Coffee, Dale, and Geneva County in AL until 12:15pm CDT. #alwx
          Tornado Warning for Geneva County in AL until 11:30am CDT. #alwx
          Tornado Warning for Covington County in AL until 10:30am CDT.

        • Ya know…. that’s a really weird thing about this place.

          Generally, approaching nasty stuff will split and pass north or south of here. Yeah, we catch bad weather, but invariably the worst of the worst either went north or south.

          Been watching it do that for 20 years.

    • Let’s do a deal GeoLurking. I send the good weather we have in western Norway to you, if you can send the rain weather to us. Has been sunshine every day here since 19.May, and we could really need some rain now :)

      • At 44 meters above Sea Level, on the crest of a ridgeline with streams flowing down to the bayous and backwaters not more than 2 km from here… not much of a chance of that.

        But, you do have to expect to get the unexpected. My driveway has border grass (we call it monkey grass) along the sides that act as a very effective water retainment structure. In really nasty rain rates, I can get as much as 3 to 4 inches of water that you have to slosh through to get to the vehicles. That is, until it flows through. Mostly just enough to make you defer going anywhere unless you want to cuss all the way to the car.

        No… I’ve got plenty of experience with this stuff. Drink a beer, bar-b-que something (whatever) and enjoy the lightning and rain and stay put.

        • yep, that is what I do, make sure I have enough food for animals and myself and watch the water rise, the yards get sloschy, it usually gets higher when the sun comes out with all the run off, mostly it is over done with 7-10 days. I got native rats in the pantry, not fun, buggers done a hole in the wall to get in, so left the door open and cats inside, one less and a cat with a big belly, blocked it with steel wool, now they are starting on another one, and mice too now, got traps and the cats love the spoils, it is messy no matter what

        • Ya know… that deal with the cats.

          Dogs were domesticated long before cats, they easily adapted/adopted humans as part of their pack. Their usefulness was in warning of a threat or assisting in dealing with it.

          Cats came along after humans found it handy to stick around and grow/harvest crops. They were the natural assistant in dealing with the rodent menace. This is also one of the reasons that we don’t mind the finicky behavior of cats. They do what they do and we don’t have to deal with the dirty work of guarding or chasing the rats/mice.

          In both cases, the “domesticated” animal gains a benefit for hanging out around humans.

          Well, that’s my take on it.

  4. We stayed at Oludeniz a year or 2 ago, it’s a lovely place with Lycian tombs scattered all about the place. Apparently an earthquake in the 50s leveled a lot of the old town in Fethiye. The family who ran the hotel were the friendliest of people, My thoughts are with the family’s and travellers in the area.

  5. And now… for the nefarious.

    There is a really, really nice paper that analyzes the risk and population exposure for Ischia. At one time, the “authors personal copy” was available on the web, but it’s no longer there. (Elsivier paper, go figure)

    By luck, somehow, the thing was still available to my Google documents account… which I have never used. I managed to get it to a local copy.

    Since Carl’s site doesn’t do this for a profit, and since we are all in learning mode here, I think I can safely get away with this. The first page is clearly labeled “For non-commercial research and educational use.

    So… I’m not going to link to it, or put any part of it on here. However, I did derive a plot using the data from within the paper.

    Table 1 of that paper provides the probability of a vent opening in a particular 1 x 1 km grid cell from Figure 6b. Using the center of each cell in Figure 6b as a reference, I obtained the lat and lont pair, then plotted the probability. Re-gridding it to cover the gaps, I get this.

    In my opinion, a probability of something happening is useless unless you specify a period of time. I couldn’t easily find a period that the author was using, so I have to be happy with this. The author states “The resulting map represents the empirical spatial density probability function of vent opening.” My guess is that should conditions start ramping up towards something, this is the probability for it to manifest itself in a specific region of the island.

    I could be wrong, but that’s my read of it.

    Anyway, here is the original article… if you have some way of weaseling it out of your references or library, have at it.

    Volcanic hazard and risk assessment from pyroclastic flows at Ischia island (southern Italy)
    Alberico, Lirer, Petrosino, and Scandone

    Journal of Volcanology and Geothermal Research 171 (2008) 118–136

    • Oh.. how they came up with the probability. They looked at and analyzed the fault systems, Bourger anomalies, locations of known vents, Radon emission levels, quake epicenters, and the fumerole/hotspring locations and applied weighting to the whole entourage via an algorithm to come up with it. The paper is mostly about how they did that.

        • Radon is a byproduct of radioactive decay… typically Uranium and Thorium. Both are part of the reason that we still have as hot a core as we do, the heat from the decaying radioactive material adding to the heat accumulated from the accretion of the Earth. So… when you have a magma nearby, one of the things that you can see is an increase in Radon.

          The presence of Radon doesn’t always mean “magma” nearby…. but an increased flux of it can mean its moving into the area.

  6. What the hell is the roughly circular expression on the map/picture? (left of the -200 on the scale)

    is it another resurgent dome or just some weird submarine structure?

    • If I understood which part you are talking about correctly I do have an answer.
      If it is the one on the upper of the two 200m images it is a boulder… Yes, they do come in that size when you have a landslide on that scale.
      If it is straight up on the image on itself, that is a landslide scar. Almost the size of Ischia itself (and that explains the boulders).

      • I think I was looking at the same thing as Stefan(?), I was looking at the circle (which shows up in several images but is easiest to locate) in the inset of the image which has the subtitle “Critical lateral collapse of the resurgent dome towards the Bay of Naples” the maybe 10km diameter circle is ESE of ischia and seems to have its eastmost border at 14′ 30E it seems very ‘flat’ on the image titled “Debris flow from a sub surface failure of the shelf around the island. The surge direction caused a large tsunami to go into the Bay of Naples.” but what is it ??

        • Then I have the answer. That used to be a part of the eleveted sea floor around Ischia. About 12800 years ago it collapsed and slid out 280 kilometers into the tyrrhenian sea.
          It is the scar of a subsurface landslide.
          Imagine being anchored on the part of the bottom that slid away. If you had a long enough anchor-cable that would be the ride of your life…

          • Provided it played out fast enough.

            I’ve watched the forecastle on ships when they drop anchor. The Maul and Pinman are quite cautious and get out of the way fast when it lets go. High speed anchor chain doesn’t mess around when it is playing out.

          • Was it sea 12,000 years ago? Was the Mediterranean not flooded about 8,000 y ago (post Glaciation)?

          • According to an article in Nature the filling of the Mediterranean Sea occured 5.33 million years ago. I could not find any source for it being dry after that.

    • I think what Stefan wonders about is the “Banco di Ischia” or “Ischia bank”

    • 2012-06-10 20:39:07.0
      50min ago 36.44 N 28.93 E 20 ML 3.3 DODECANESE ISLANDS, GREECE 2012-06-10 20:55
      earthquake2012-06-10 20:32:33.0
      56min ago 36.46 N 28.95 E 15 ML 3.2 DODECANESE ISLANDS, GREECE 2012-06-10 21:01
      earthquake2012-06-10 20:07:30.0
      1hr 21min ago 36.40 N 28.93 E 20 ML 3.2 DODECANESE ISLANDS, GREECE 2012-06-10 20:37
      earthquake2012-06-10 19:59:08.0
      1hr 30min ago 37.74 N 26.69 E 2 ML 3.1 DODECANESE ISLANDS, GREECE

  7. Mount Rainier just had a 1.3 mag at 2 miles deep directly under the center… Sunday June 10 2012, 21:38:09 UTC 23 minutes ago Mount Rainier area, Washington 1.3 2.9 USGS Feed

    • See my standard reply abut quakes in volcanoes. If it is below two it has no effect if it does not come in hundreds. I only lift my left eyebrow if it is between 2 and 3M. Above 3 and if it is exactly inside the volcano, then I get interested.

      • would the 5.4 – on Tuesday, June 12, 2012 at 05:59:39 UTC
        Tuesday, June 12, 2012 at 12:59:39 PM at epicenter
        Location 5.675°S, 105.474°E, ( Krakatoa)
        Depth 172.5 km (107.2 miles)
        get you interested ?

  8. if one looks at the med, the quakes are spreading slowly but surely in both directions, in the west they are now just outside the med, with some in Spain and NorthAfrica and in the east today’s lot

  9. One gallon of Cider started. The Peach wine is up to 2.9% ABV. It should top out at around 8.5%, but the cider will probably get up to 9%. (boosted the available sugar with honey)

    • HI GeoLurking

      What is your recipe for the cider ?
      I have tried ti do some homebrewing beer a few years ago, so I have some equipement, but the beer results were not that good. Why not try Cider ?

      Nice article Carl, thanks

      • Yeah, my beers skills aren’t that good. And not having access to a ready supply of apples is frustrating.

        However. You can cheat.

        Mott’s Apple Juice is 100% apple juice and has little if any preservatives. Preservatives can kill your yeast in a flash.

        The Brix rating out of the bottle is 11. (11% fermentable sugar) That gives an 6.3% ABV if it goes the full course. I like to boost the sugar content a bit before I start so that I get a higher yield. You can use sugar, or honey. If you use sugar, you need to add about a quarter teaspoon of lemon juice to act as a catalyst to help cleave the sugar into it’s simple sugar components. The yeast will preferentially act on the fructose first then it will use up the glucose.

        After I have the juice in a clean one gallon jug, I add my yeast. I use standard bakers yeast, but you can find/buy yeast specific to beverage manufacture, but that depends on how much fiddling you want to do. I then place my air trap on top (lets out the CO2) and monitor it closely for the first day to make sure that my yeast is alive. If it doesn’t start producing CO2, you have to take corrective action by adding a bit of lemon juice to get it into an acidic state (doesn’t take much) so that you don’t get a bacterial contamination. Then I re-pitch the yeast. (Once the yeast is producing, the alcohol will keep the bacteria away.)

        Some brewers like to start the yeast in a small sample of the mix first so that they have a viable strain. This works, but takes a bit more time. One key thing that I have found, is that you want to start the yeast with as small an amount as possible so that it grows into that environment. Using too much and you can get a flavor of bread in your mix.

        Once your yeast is alive and happy, let it do it’s thing. Dead yeast will settle out on the bottom.

        If you want “fizz” in your final beverage, fill your bottles and cap them just before the yeast stops. You can monitor that my how fast it produces CO2 bubbles. Catch it too early and the bottles could over-pressureize. I use 16oz beer bottles and metal caps. Make sure that you draw from above the sediment so that your Cider is as clear as possible. Shaking the jug doesn’t help.

        If you have another jug, you could rack off the mix and leave the sediment behind and finish in a separate jug. (topping off with sugar water or fresh apple juice in the new jug)

        If you go for a full ferment, and let it go until it totally quits, you can clarify it with bentonite clay (get some sterile clay from your local brew shop) Make a thin solution and mix it in. In about two days the cider will be crystal clear and you can then rack it off. The problem is that it will have little if any “fizz.” But it will be pretty.

        At this point.. you have one of two options. Apple Cider is Apple Cider. Apple Jack is different, and may skirt the boundaries of legality where you live.

        In a plastic jug, freeze your final fermented cider. Allow it to slowly melt and drip into a fresh container. As it does so, the alcohol melts first and the water last. This will boost the strength to a much higher level… provided you don’t let the whole concoction melt. you can achieve alcohol concentrations rivaling that of whiskey.

        Ultimately, what your yield is depends on the available sugar at the start. Anything more than 30% sugar (30 Brix) is a waste since yeast quits at about 18% ABV.

        0.575 x brix = potential yield (ABV)

        On my original attempt, I boiled down my cored apples and extracted my own juice. It works, but it’s a pain in the arse.

      • As for the beer… I had reverted to an older recipe, similar to the beer out forefathers drank on the warves. 25 to 40 percent oat and the rest barley.

        Tastes a bit like crap. But if you can get 2 or 3 pints down, you don’t care.

        Though I probably over hopped it to compensate.

        My problem is that the absolutely best beer I have ever had, was Murphy’s Stout. Having spent a port-o-call in Cobh, I am spoiled. Eventually, I will get something close to the dark rich flavor, but until then.. I experiment.

        • Well I can’t help you for the Stout. Only thing I know is that I can buy in nearby Belgium some “beer kits” looking like a canned soup metal box, where all you have to do is add water sugar and yea. They do have kits for stout-like beer. However the results I had were not overwhelming. Thanks bery much for the cider recipe. I think I will give it a try.
          For your information I do not know about the french laws for apple jack but some people still have an hereditary right to distill 1000 ° of alcohol (and many have some illegal stills but usually you do not peak of these things). Unfortunately the right to do so dies with the last person to hold it, so it will not last long now.

  10. Recently, WUWT featured an article about some newly discovered “black smokers” in the Gulf of California.

    http://wattsupwiththat.com/2012/06/09/deep-sea-hydrothermal-vents-discovered-in-gulf-of-california/

    This region is the southern end of the San Andreas/Imperial fault system and rather than the typical strike-slip of the San Andreas, which is a transform fault the line is interspersed with spreading centers. (like the MAR).

    I had known that there were black smokers down at that end, but evidently the big hoo-ha-ha is that they found some more… with an autonomous side-scan sonar mapping submersible bot. Way cool.

    Anyway, I sat and mulled that spreading center feature a bit. The Pacific Plate is moving NW relative to the North American Plate, which is moving to the West and a bit South based on everything I’ve read. So, why the spreading centers? That would imply that something is moving south on the other side of them, and that should be the North American Plate… which is moving west?

    No, not a paradox. It’s an artifact of the Euler Poles.

    http://en.wikipedia.org/wiki/Euler%27s_rotation_theorem

    Ya see… plates don’t just follow linear motion. They rotate. The center of the rotation is the Euler pole. You can see this in Google Earth when you look at the sea-floor (or any good sea-floor map.) notice that the Fracture zones do not follow straight lines. They follow an arc that gives you a good hint at where the Euler pole is at. (mostly)

    Euler poles move around and shift depending on the prevailing forces on the plate. In the case of North America, it’s reversed motion at least onces since the Jurassic. Right now, the rotation pole is located somewhere up in Canada. In the case of the spreading centers, that is the relative motion of the two plates in that region.

    Anyway, if you want to dig more into it (KarenZ), here is a good paper.

    http://web.ics.purdue.edu/~ecalais/teaching/kinematics/plate_motions.pdf

  11. Nice article with plenty of inspiring food for the yellow-page press & scare-mongering sites… Can’t deny the facts, though!

    • Hello Jack!
      I had about a half a year of a thinker before writing the Italian series.
      In the end I decided that Naples area might be the only place on the earth that would benefit from a few articles that are scary. That might actually get the politicians doing something to mitigate the risk. Because the greatest dangers are due to unwise politicians and illegal property building.
      It was kind of a damned if I do, damned if I don’t thing. And it was not with an easy heart I wrote it with the alarming details left in. In the end I decided to scare people, in the hope of saving people. And as you wrote, in the end the facts are facts. It is a scary and potentially very dangerous place.

      • humans are known to play Russian roulette as regards to danger, a case of taking the good with the bad and hope/does not to me/it won’t happen

    • Mike, the quakes are small and I do mean small. They are at 1.1 km, which means it’s the default depth assigned until it can be accurately calculated and they are also assigned a low “quality”. Since they are hours old, they haven’t been thought interesting at all by IMO. If they were, I guarantee that IMO would have had them investigated within the hour. Thus, it’s not “activity at Katla” as such, but rather “activity in the Myrdalsjökull glacier” and quite normal for the time of the year. :)

      • They’ve started to look at them and it turns out they are indeed glacier-related at 0.1 km depth. As it takes 32 mag 1 earthquakes to equal the energy release of a single mag 2 one and these quakes are in the range 0 to 1 (with a couple of slightly larger), it’s no great shakes.

  12. Hi Carl. Just to inform you, Monte Epomeo is NOT a volcano, rather it is an uplifted segment of the island caused by a shallow magma chamber.

      • Yep, but there’s also this to consider – what sits atop an active magma chamber and what is the volcano proper?

        • A volcano has two possible meanings:
          -An opening in the earths crust through which lava can erupt.
          -A mountain formed as a result of volcanic activity.

          • And both of those meanings work for both Ischia and Monte Epomeo. But, I would give Monte Epomeo a lead on the second cathegory, and that is why I chose to use Monte Epomeo as the name for the volcano itself.

          • I’m with Carl here as Ischia is the name of the island.

            Pieter, that definition is rather old-fashioned and blunt wouldn’t you agree? The mountain is no more than a rubbish dump for volcanic products. The mountain does not erupt but rather, the volcano erupts through the mountain and sometimes to the side as with Fimvörduhals. Since there were two fissures through which lava erupted, I suppose that it meets the second definition but that’s illogical. I’ve found it far easier to get my head around what is happening if I think of volcanic edifices, monogenetic cones, maars, calderae etc as “the surface expressions” of the volcano proper, i.e. that which produces the magma and energy responsible for the eruptions.

            I know perfectly well that 99.9% of humans, if not more, associate the term volcano with a tall, cone-shaped mountain spouting fire at its peak same as physicists have a far different interpretation of “solid” than 99.999% of human beings. ;)

            • I did not invent these meanings. These are both scientifical terms and terms used in society. The two are highly confusing, but there is no possible discussion about it.

          • Hello Pieter!
            We know that it is the given definitions. But I do not agree that they are not open for discussion, everything is and should be that.
            Myself I prefer to look at the definition of a volcano root upwards.
            First starting with the driving process, feeders up to the chamber system. From a chamber or sill system upwards a volcano in reality just becomes vents of various types and sizes. The real action is before that, and should be the base for the definitions. My opinion.

    • Hello Lucas!
      Older sources states that Monte Epomeo is a horst/graben structure, new papers state it as a resurgent dome. Either way, it is a part of a volcanic structure. And since it is the highest point of the volcano…
      Ischia on the other hand is secondary uplift material, so that is even less a volcano. The vents that lead down under Monte Epomeo is not volcanoes, just vents, so you can not use their names.
      In the end I chose to use Monte Epomeo as the name for the volcano that is a large part of the Island of Ischia. GVP choose to use Ischia. Style and definition choices really. I though hope I was clear that it is a definition issue.

      • Would not large piston collapse calderas (Yellowstone) constitute a grabben of sorts? Likewise, would not a huge dome constitute a form of horst?

        Structurally, they fit the category… though the causes are likely quite different than the features that the terms were originally used on.

        • Carl, another meaty article!
          Personally I have no problems with a 10km caldera roof, with uplift mechanism by ‘point divergent’ cone-sheet intrusion – refer the Tertiary Ardnamurchan complex in west Scotland of comparable size
          56 44′ north/ 5 59’west

          http://maps.bgs.ac.uk/geologyviewer/

        • Yes, it does constitute a graben of sorts. But I kind of think of volcanoes bottom up, and the driving forces for a graben is a bit different than a resurgent dome.
          In the beginning they judged the Monte Epomeo to first be a Graben before new data gave that it was a rather over-sized resurgent dome. If memory serves Yellowstone was also first a rather large graben, and then was redefined as a resurgent dome.
          If memory serves a graben is not supposed to be so deep that it can start at the level of the magma chamber.

      • Yep,i’ll agree with you with that (Ischia is one strange volcano isn’t it?)

        I got the information from the (excellent) book ‘Volcanoes of Europe’ from 2001. So i guess a lot changes in 10 years.

        • Hello Lucas!
          Yes, the way the researcers look at Ischia has changed during the last decade as new data has come in. When I researched before writing the paper I found a rather large shift in the way they describe it during the last 10 years.

  13. Carl, truly excellent article! While Ischia may be the most “loaded”, I doubt it’s the most dangerous, but let’s defer discussion until you’ve done the final installment! ;)

    • In short, Ischia is more likely to do something that kills X number of people due to having a larger magma load, and also due to the substantial risk of landslide causing tsunamis. And the last part is very hard to predict as you know.
      In the very long run (deca-milleniums) it would be Campi Flegrei, but I chose to stay with the risk for our generation.

        • Yepp, especially since I believe that we will come to basically the same conclusions… …namely that it is Pantelleria that is the most dangerous volcano ;)

  14. For those who like clear readings of an intrusion I would recommend this one:

    It is visible on Skro, VAT and MJO as well. But the best view is at Jökulheimar.
    It was probably an intrusion running from Bardarbunga down towards Torfajökull along Veidivötn. It coincided with 2M earthquake. They do not come clearer than that.

    • And now a second run has started.
      Interesting since it has started to cause quakes. Albeit small and weakish.
      Sofar there is one confirmed at Veidivötn (Siguldastöd), but as a measly 0.2M.
      I would like to point out that this activity is interesting, but not more than that.

      • Aha, Carl, that 0,2M “near Sigalda” is exactly in “upper end” area of Hydro-power station tunnel still under construction (and new dam), namely at Búðarháls Power station, and likely small rock blasting…

        • He, I was correct, it was interesting :)
          But thank you for pointing out that it was interesting in a different way than volcanically. Now we all know what shallow quakes are in that area means.

          • Ok, VC, I agree on possible intrusion happening – but in green band (meaning further away than Vatnaöldur) starts coinciding with Katla swarm in morning, and does not show further east (grf, skr etc.) then this leads me think Eldgjá rather than from Hamarinn.

          • and, yeah (just after I hit enter), then SIL updates show Askja tremour rizing and new quakes in Katla too.. beginning wondering on interesting day(s) ahead?

          • dead zone is shaking :) eheh
            maybe at some 30km deep, magma has pushed right at the hotspot southwestwards into Katla or Veidivotn…. just my 2 cent dreaming…

          • Anyways I never understood why people sometimes have a problem with visualizing this. Iceland is actually fairly small and between Vatnajokull and Katla is a small distance, geologically speaking. I can easily imagine that magma movement…

          • If people can’t imagine magma movement on that scale, wonder what the Earth-encompassing MAR does to their minds? ;)

  15. Monday June 11 2012, 14:00:18 UTC 11 minutes ago Dodecanese Islands, Greece 3.9 10.0 CSEM-EMSC Feed

  16. wow, brilliant write-up Carl. I go away for three weeks and now it seems like I’ve got 3 weeks of solid reading to catch up on, including Erik’s on mineral forensics (man, has that been a long time coming! I’ve been waiting for something like this from him for a long time! Makes me hungry for more).
    I never realized Ischia was quite so big nor quite so resurgent.

    • I think that today… God has a sense of humor. I turned the light switch for the hall light off and power for the entire house shut off.

      ???

      Turned it back on and the entire house came back on. Then I heard the thunder.

      • LOL

        Reminds me of a thunder storm years ago that was rolling around directly overhead, so I said to hubby that perhaps we ought to turn the telly off….

        Nah – he said, that’s just an old wives tale……

        Bang!

        Luckily – modern electrics – just the trip-switch had kicked everything off! It was one heck of a bang, though, as the lightning struck the house. Couldn’t see any damage after, though, so reckoned we were pretty lucky really.

        • I had a bolt strike on the other side of the field next to the YMCA… about half a kilometer away. My TV had a purple and green screen for a few days. The bolt had magnetized part of the TV screen. It went away after a while… more modern CRT based TVs (pre flatscreen) have a degaussing coil built around the face of the CRT. After a few power cycles the tube components are demagnitized.

      • I lost a fax/answering machine and phone line, fridge/freezer to something like that, at 5am, after dark and scary. had electricity fixed by 10 am, new appliances within a week and 18 month for new phone lines, they had to redo a deep underground access line

  17. I was out of town for most of the weekend, so I didn’t have time to join in on this week’s lava competition. But I caught up on the postings when I got home yesterday afternoon. After that, I started watching “Ancient Aliens” and lo and behold they started talking about the 3 mummies found on the summit of Llullaillaco! I yelled out, “I know those mummies!”. My 3 granddaughters were visiting and they looked at me like I had totally lost my mind. I was so proud that I knew about those mummies that it was almost as good as winning a point. :D

    Nice post on Ischai, Carl.

  18. June 10, 2012

    Guatemala / Fuego and Colombia / Nevado del Ruiz
    – Volcanic tremor is slowly on the rise again at both Fuego (Guatemala) and Ruiz (Colombia).

    Mexico / Popocatepetl
    – Eruptive activity remains subdued (compared with the past few weeks!) at Popocatepetl (Mexico).

    California / Mammoth mountain
    – Mammoth Mountain (CA) has returned to quiet following Friday’s brief burst of seismic activity.

    Chile
    We have received no new information about the burst of seismicity near the Chilean volcano, other than that Chilean seismologists felt that the episode was purely tectonic in nature.

    http://earthquake-report.com/2011/12/31/worldwide-volcano-news/

    • They are going to collect samples and perform? … I wonder what play they are going to do and if there will be a live feed. This could be entertaining.

      ( Yeah yeah, I know, but I couldn’t resist the jab :D )

      It will be interesting to see the results of the sample analysis.

        • Did you too, for a fleeting moment, in your mind’s eye see the multi-talented Professor E directing Snegurochka?

  19. 11.06.2012 | 11:57

    Series of Quakes Hit Katla Volcano in South Iceland

    A series of earthquakes began in the sub-glacial volcano Katla in Mýrdalsjökull, south Iceland, shortly before 5 am this morning. Between 5 and 6 am 14 minor tremors were registered there, the strongest of which was 1.6 points on the Richter scale.

    Between 6 and 8 am, six other minor quakes were picked up by the Icelandic Meteorological Office’s sensors, but after that the series subsided, visir.is reports.

    Geographer Sigþrúður Ármannsdóttir at the Icelandic Meteorological Office, said the epicenter of the quakes were in the craters that opened up during the minor eruption in Katla last summer, when the river Múlakvísl flooded, tearing a hole in the Ring Road.

    Sigþrúður believes they were caused by geothermal activity. She added that increased conductivity that has been measured in Múlakvísl lately might indicate that geothermal water is leaking into it.

    Approximately one month ago a small glacier outburst occurred in Katla which lasted a few days. Seismic activity in the volcano was picked up by sensors, as well as increased conductivity in Múlakvísl.

    The reason was also believed to be increased geothermal activity in one of Katla’s craters.

    http://www.icelandreview.com/icelandreview/daily_news/Series_of_Quakes_Hit_Katla_Volcano_in_South_Iceland_0_390791.news.aspx

    • Luis, please. I know the Dragons have told you many times NOT to cut-and-paste whole articles.

      • @Luis.

        Some advise. I ran into the problem of posting too much stuff in links and such. Generally the copyright holder (if a news company) could go after the site and hit them with take down harassment notices and whatever spineless lawyers could think of.

        So… I adapted. When I’m trying to convey what another site has said, I try to minimize the quotation to something that conveys the meaning, or I paraphrase it. Then I point at where it came from via a link (if available)

        An example from your post:

        Series of Quakes Hit Katla Volcano in South Iceland

        A series of earthquakes began in the sub-glacial volcano Katla in Mýrdalsjökull, south Iceland, shortly before 5 am this morning.

        …14 minor tremors were registered … strongest of which was 1.6 points on the Richter scale…

        Sigþrúður [of IMO] believes they were caused by geothermal activity.”

        http://www.icelandreview.com/icelandreview/daily_news/Series_of_Quakes_Hit_Katla_Volcano_in_South_Iceland_0_390791.news.aspx

        Sure, you loose the actual phraseology of the post, but you convey the gist of what it was about.

        Anyway… that’s the way I do it. Use it if you like.

    • One week ago I flew over Myrdalsjokull and I saw nothing special. That is, the cauldrons created in July 2011 were covered by new snow, and no new cracks were detected. So, I guess this is only minor activity. I have doubts that Katla will erupt this summer, I think we will still wait at least 1 or 2 years more. I think Henry and Carl also agree with me.

      With no new and significant deep earthquakes under Katla, how can we expect an eruption in soon? No, sorry I think we are still far away from it. We need to see first an increase in significant earthquakes, from the deep upwards. Something that happened before Eyjafjallajokull and which has not been seen yet in Katla.

      Until then, we will see many instances of very minor floods, occasional harmonic tremor, and once in a while increased conductivity. Just the kind of stuff that happens regularly in Grimsvotn too. To put it clearly and bluntly: no, no eruption this summer.

      • I like not agree. Generally. Some time ago I had a good look at Hekla, and saw nothing special or out of the ordinary (I think). That does not proof anything. Eruptions come (more likely than not, given small Geological time anyways) but maybe not soon or big. Icelandic eruptions usually are not large, but we have many “situations” here: Hekla probably has “enough”, Katla probably had one last year, so why not another (minor) next week?, Askja “maybe, mabe not”, Carls “bunga too, Krisuvík unknown, Grimsvötn probably past one year recovery time and preparing for next?, and even Dead Zone seems not so very dead (I think) *rant off*

        • Yes, you are correct.

          Katla can likely have more minor subglacial eruptions this summer. I was referring to the large VEI4+ eruptions. I think a large one in Katla will still be a few years ahead, but that is just my biggest guess, so far no deep earthquakes or apparent magma movements at depth. I still think Katla will NOT have its big one this summer.

          Grimsvotn is certainly going for the next one, within (conservatively) 10 years.

          Hekla is a big gamble (it is probably ready for one, but it can break off its pattern and leaves us waiting for long).

          Askja is getting there (many intrusions have happened there); in my opinion it is ready for at least a minor 1961-like fissure eruption. It is a big gamble too. It can be next week, or years from now, but it is definitively nearing something.

          Hamarinn is another very likely candidate. But this is a volcano long dormant, it is difficult to say what might happen, minor ones? yes, very likely, I even think a minor fissure might likely open within the next years, even in soon.

          And now we are beginning to see increasing activity just around Vatnajokull, in Tungnafellsjokull and Kverkfjoll (with deep quakes, but in my opinion still years ahead to some eruption).

          Krisuvik: no solid signs leading us to see am eruption coming. It has some restless behavior once in a while, but I think any eruption will still be years into the future.

          So, my bets go for Askja, Hamarinn and Grimsvotn as the only volcanoes likely to erupt this summer (by eruption, I mean something excluding subglacial VEI0s)

        • To make it short, I think Katla cannot have its large one in soon, because there has not been any significantly deep earthquakes happening there, or any significant size earthquakes either.

          If the volcano is going for a large VEI3+ boom, then we should see first a rush of deep magma, as a column of earthquakes first deep then shallow (but not tiny ones, but larger M2 to M4 earthquakes). This was observed before Eyjafjallajokull, my guess is that we should see something similar with Katla if it is going to erupt.

          • However the fun of it, is how long will these subglacial unconfirmed eruptions going to last. So far they have been small, as often occurs in Iceland. This kind of activity is occurring because magma is under pressure (chamber/sills at 3-5km are likely full), but still there is a lack of pressure (overall) to make it go through a large boom. For that, I think we need a new large influx of deep magma that makes the whole kettle boil and overflow.

          • Islander, I think Katla with a tectonic movement would be a seriously bad idea…
            Last time that happened with had Éldgja.
            The reason for Katla having/causing few large scale rifting dead zone eruptions is that down there the comparative tectonic motion is less than it is for Grimsvötn and Especially Veidivötn/Bardarbunga.
            So, I do not think it need a lot of tectonic push for it’s normal eruptions.

          • I think you’re both right. The likelihood of Katla having a large eruption, a glacier-breaking VEI 3+, is pretty low whereas there’s a decent likelihood of a minor, subglacial VEI 0 (but volume-wise in the range VEI 0 – 2). To judge by past performances, always risky but the only yardstick available in the absence of fresh data to the contrary:

            Major fissure eruption (Holmsa, Eldgjá): Probably thousands of years away

            Major silicic/evolved magma (VEI ~4): Ditto unless there’s an untapped reservoir under the northern part of the caldera in which case it could be bigger – but this scenario is extremely unlikely as the major intrusions necessary seem to erupt on the flank as major fissure eruptions.

            Large basaltic fissure eruption (i.e. the 1755 subglacial VEI 5): Needs a major influx of magma as Irpsit argues, thus most likely years in the future.

            Minor basaltic fissure eruption (i.e. the subglacial 1955, 1999, 2011 VEI 0): As it needs only a minor influx and the plumbing seems to be open enough to let one through without major seismic unrest, it could happen next week or in twenty years’ time.

            As an intellectual curiosity only, imagine a repeat of the 934 flank eruption (Eldgjá), 15 – 20 cu km of 1100+ C basaltic magma, through the middle of the caldera…

          • but.. but Katla with Tetonic push, basically is Dead Zone cycle (Eldgjá) and are part of this “situation” I think. Why only hink in single mountain terms? Co-eruptions in same year, or within same season ar maybe not likely. We had one rather large last year and maybe nothing this year…

  20. Is anyone else having difficulty getting onto this thread today? It is taking a very long time. Are you making any changes to anything, Carl?

    • No, I am not doing any changes, and for me it takes normal time.
      Only thing (other than a problem on your end) I can think of is that this is a larger than usual article.

      • Clinically free of interpretation of the nature of the quakes apart from the nonplussing “normal summer earthquake swarms”, which invites misinterpretation. Also misrepresenting them as being much larger than the typical M 0.7 with a directly misleading “the largest earthquakes being around ML2.0 in magnitude”. Of the 28 quakes in total, 12 were between M 1.0 and M 1.7 and 16 between M -0.4 to M 0.9 with the typical dept of 0.1 km meaning icequakes! Of the investigated quakes, there was only one of interest, a measly M 0.4 at 12.0 km depth.

        Hardly the stuff to devote a blog post to.

  21. Update from my friends which have hiked a few days ago Eyjafjallajokull: everything went well, the glacier has been gradually covering again the volcano crater and the very thick ash. No new lake (Askja-style) was observed.

  22. While we’re on the topic of Italy, what’s the deal with Alban Hills? For all the talk Campi Flegrei gets, why does Alban Hills get nothing?

  23. Good morning/evening everyone. I am back to almost normal again, whatever is normal for me! :)
    Carl What a great Post. I too didn’t realise quite how large Ischia is. Oh How I love all this learning!
    Congratulations to last week’s winners. I was in mid hunt when I was so cruelly torn away.I love the weekend sleuthing sessions.Maybe I shall start letting my upper lip hair grow like Poirot!
    Maybe this link will help put Katla watchers at their ease. Certainly I think this is early summer activity with the Icecap melting. Geothermal activity maybe but looking at the bottom quake graph it doesn’t show rising magma particularly threatening.

      • I would like to say a big thank you to The Icelandic communications company Mila . It is thanks to them that we can enjoy such wonderful views of Iceland from our own homes. They are so good at keeping the Live Cams working. I greatly appreciate this service.

        http://live.mila.is/english/

      • Actually, it’s the geyser Strokkur, not Geysir that erupts every 8 – 10 mins. Not that a name lessens the spectacle. IIRC Geysir is the still, circular pond in front of Strokkur, she does actually erupt once or twice daily – especially after the employee with the the packet of washing powdre has come by. It appears detergents can trigger an eruption as it lowers surface tension, hence IMO keeps a close watch on Katla so that digrunteled scientists and 2012-ers don’t get an opportunity to dump detergents in significant amounts.

    • Good morning Diana, oh did you make me laugh with the bit about growing a moustache like Pirot. Well its night time here for me so BBGN , hope you all have a good day.

      • Hi Hattie. Good to “see” you. Trouble is my moustache would be blonde and not very noticeable. I suppose I could dye it! :D

        Have a peaceful night Hattie and Shleep well!

    • Lurking, We in Britain are suffering too. Bad floods and storms. We don’t have the compensation of watching dramatic thunderstorms as you have. We just get cold heavy rain. Having said that for a change it is the south that is suffering. We are not too bad up here in the North west.
      The UK met office have said that fewer hurricanes are expected this year…..You have suggested your weather is perhaps a way of releasing energy. Perhaps you are right. If our jet stream up here is doing a wobbler then that will probably have an effect on high altitude air streams further south. I don’t know too much about them, also perhaps the sea currents change tack too. Combined that will affect surface weather. Interesting and more reading for me to do !!!

      • Dunno if watching them is for entertainmet or self preservation. I’ve had tordoes rip the roof of the house and generally mess things up. It gets to the point where you pay attention… or else.

        In a way, it gives you a connectedness. But the wife still goes nuts at inclement weather… concidering her experiance with a tornado was me barking orders at my mom and her… I can’t really blame her. A CPO can be blunt about solving problems.

        • We are starting to have more and more tornadoes here in Quebec. Small (F1), but still dangerous. We never had to bother knowing anything about that natural phenomenon before, but having had a few close calls in the last few years, it would be smart to learn what to do in case one gets really too close. New problems…

    • It has stopped snowing for this year (I think)…
      Once I was celebrating midsummer (think 4th of July) in the end of June while snow gently fell on our BBQ.
      But for now it is sunny and plus 20C. Unusual and likely to end with bad weather again.

      • Oh, and I had intended to write that since the beginning of march the prevalent wind has been northerly. This wind drags down arctic air (cold). This never before heard of long duration of northerly wind has made this the coldest and most miserable spring for 40 years.

    • Hello to All —

      I’m with my students in southern France and the internet connectivity at the school here leaves a bit to be desired, so I am reluctantly absent from the blog most of the time :-( In fact it took several hours to get a stable enough connection to send these two paragraphs. The interesting thing to me though is that I am now in synch with most of you time-wise! :-)

      I certainly can’t complain about the weather here, as it has been sunny and rain-free for a week and a half! But yesterday there was quite a bit of the Mistral blowing, and I was wondering if that was due to what Carl mentioned about the prevailing winds being from the north. I take each day here as a surprise since European weather never seems to fit into my preconceived notions of what it is supposed to be.

      • Hi Denise, I hope the trip is going good, and the students are not giving you to much of a hard time.

    • This was one of the moments I wish I didn’t read german fluently…
      Except for the alarmist nature it is also riddled with errors.
      The largest of the errors is that anybody is even close to detecting and calculating the average time between larger disasters. And we are far far more distant from being able to calculate the frequency of smaller disasters.
      My take on it is that shit hits the fan now and then. And that we will need a couple of hundred more years of research to be able to even get the statistical material needed to do what the “article” says that they can do now.

      • I am pleased to share my good news just been to see my Dr the hospital had faxed my results to him my biopsy showed the polyp was benign and I am in the clear. I feel like a noose has been removed from my neck and the past few months have made me appreciate more my time with my husband family and friends and that material things are all for show and dont really matter at all.

      • I really have to read things twice in German these days, I have not much opportunity for it, must have gotten it wrong. Thanks for clarifying

  24. Thank you all for your good wishes.

    On the Avcan FB pge they are discussing a very rare earthquake yesterday between Fuerteventura and the Western Sahara has any one else any thoughts on this.

    2012-06-11 23:29:53.2 30.52 N 10.03 W 26 mb 4.1 A CANARY ISLANDS, SPAIN REGION MAD
    2012-06-11 23:28:24.9 24.77 N 13.28 W 10 mb 4.3 A WESTERN SAHARA MAD

    • Is there any link to where they saw those quakes?
      The reason I am asking for an original link is that when I check USGS and CSEM-EMSC they do not list neither of the quakes…

      Regardless of that, it is not unusual with quakes in that area. Abundent rifts in the area created as the MAR created oceanic crust slams in under Africa, and also created as Africa moves upwards…

      It is all in the tectonics you know.

        • Avcan comments by Henry Translated.

          ,,And back home the truth is that the activity there these past few days in the Azores – Gibraltar – alignment Alboran Sea – North Algeria, leave indeferente no one, especially considering that if you move to the left (Azores – Gibraltar) and turn right (North of Algeria) in same alignment, by that does not in the center of that line in the Alboran Sea area?. When can less always think that in that area the rift Moroccan, and its continuation under the Mediterranean seems be dissipating efforts, qunque that if too much activity in the area for my taste, hopefully it’s not prelude of something major….(Henry),,

          http://www.facebook.com Avcan

        • Thank you for the link.
          When I check the data it is rather uncertain. When I check the regular list they seem to have been removed.
          Regardless of that, it is quite common with quakes in the general area, something that is becomes quite clear when checking lurkings link below.
          And AVCAN is a bit excited if they believe that will cause anything in the Azores or Canaries.

          • Does not Lurkings Link though only show the quakes from mainland Spain .

            The unusual EQ Avcan were discussing was the EQ from Fuerteventura to the Western Sahara which did not show on Lurkings link.

          • Avcan comment Translated.

            ,,And then there are… very rare rare things, i.e. of yesterday of a possible earthquake between Canary Islands and the African or the Western sahara coast… not out anywhere in the IGN, but if in the EMSC… notice, the first along the African coast to 430 km from fuerteventura to the ENE and the second towards the maral S 430 km from fuerteventura in the middle of the Western sahara…. between both 631 km…. rare rare… the earthquake It happened in one of the two sites, but not to be conclusive data, they do not put…(Henry),,

            http://www.facebook.com Avcan

  25. One idea proposed is that deglaciation leads to volcanic eruptions. Hmm… If you look at the “Up” component of Grimsfjall – http://hraun.vedur.is/ja/vatnajokulsvoktun/gps_faersla.html – you can see how the glacier gains in winter and loses during the summer. Now, in 2011, the seasonal melt didn’t have time to more than just begin before she erupted. It is quite clear that the glacier was then at its thickest when this happened, so perhaps it’s not such a foregone conclusion that it is deglaciation that leads to eruptions.

    • I think that a slight loss of mass on top of the volcano crater may be conducive to eruption if the magmatic pressure beneath is at a maximum. I believe that last year’s “eruption” happened because the magmatic pressure below was not a great as it could be. Maybe a shove into a dyke pushed the magma near to the surface and thus partially melting the ice which blocked the vent, which caused a glacial flood.

    • not actually a cyclone..but has winds of the same speed as a category 2. The category of cyclone is based on wind speed and the central pressure of the system.

      Perth receives pretty much all its yearly rain from storms from the southern ocean (or south Indian ocean) b/w march and october, so not that unusual. Cyclones originate from between the equator and the tropic of capricorn between oct-march

  26. @ Inga & Stoneyard
    Thanks folk!
    How are you getting on, both – long time no see here!! :-)

    • Busy packing and moving things to our new house, and making some minor renovations between 2 jobs… not too much free time. :)

  27. I’m away for a while and Italy shakes and has tornados in Venice… The 2012ers really mess around as soon as you don’t have all eyes on them…
    Forgive me if I don’t even try catching up. It’s a pleasure to read and see the troops still have all of their charms.
    Hi all. Hope your all well.

    • …you’re all well…
      Some things always stay the same. With time I’ll probably learn to love the automatic corrector…

      • Hello Loco! Done any 2012er bashing since last time? The seem to be getting rare, maybe even an endangered species?

        One shouldn’t indulge in wishful thinking, I know…

          • Oooo! Parallel realities manifesting, how neat. If you are a believer, you will branch off on that timeline. How utterly gratifying!

        • Hi Henri,
          Actually I did some, but job-wise, not “for fun”. Although it was a bit fun. Some truly began worrying what effects the Italy seisms could have where I work… Just ridiculous… :-)

          • Haven’t you heard?
            The lizzard aliens have placed ancient ultra-technology rocket-engines under the entire Suisse. The goal is to have all the chocolate and cheese they need flown through hyperspace to them.
            Launch date is the 23rd of Decemeber this year. Suisse will survive, the rest of us die.

Comments are closed.