Once in a Blue Moon

Guest Post by Albert:

A well-known but little understood expression in English. ‘Once in a blue moon’ is used to describe something that happens very rarely, but which is not impossible. But what does it mean? Does it have an origin in astronomy?

What is a ‘blue moon’ or ‘blue sun’?

From experience, we know that the sky is blue, the sun yellow, and the moon dark grey. Seen through cloud, the Sun or Moon change brightness but their colour does not change, although it becomes harder to discern the colour. Only at sunset (or for early risers, sunrise) can we see a red Sun, caused by absorption and scattering of blue light in the atmosphere. The air molecules, water droplets and dust particles affect blue light more than they do red. With a long path through the atmosphere, red light gets through but blue light is removed. The result is a red Sun. The scattered light is what makes the sky appear blue.

There is however an exception. Particles of size around 1 micron affect red light more than blue. This unusual situation makes the Moon or Sun appear bluer. It would not be notable against a blue sky, but in such conditions the sky will become greyish (and perhaps even red): the contrast between the sky and Sun makes the Sun appear blue. It is magnified by the tendency of the human eye to assign colours in contrast. Photographs (this one from Brisbane, 2009) of the effect tend not to be show it as well, but the effect is marked to the eye. It only works if the particles are of quite uniform size: mix grains of sizes which are different by more than 50% and the effect goes away.

After the Krakatoa eruption in 1883, blue Suns and Moons were seen across the tropics for a month, following the large cloud of volcanic dust and ash moving around the globe. The cloud circled the Earth twice, each circle taking 13 days. The blue Sun was first seen around the Indian ocean. One report describes how the Sun appeared green at sunrise, becoming blue as it rose higher. Krakatoa was unusual in this respect, though: in general reports of blue Suns or Moons after volcanic eruptions are rare. In September 1950, large peat fires in Alberta led to blue Suns and Moons being visible from Canada and a few days later Europe. The event is still remembered across Britain. Patrick Moore wrote a few years later:

The moon was in a slightly misty sky and had a kind of lovely blue color comparable to the electric glow discharge. I never saw something similar before.


  (Gedzelman and Vollmer 2009: blue-green sun over Boulder, Colorado)

Many people have suggested that the expression ‘Once in a blue moon’ referred to rare events like this. I became curious about this, and tried to find out more.

How old is the expression ‘blue moon’?

It is a uniquely English expression, and does not occur in other languages. But there is surprisingly little mention of it in the older English literature. Where it is mentioned in 20th century writing, it is often as a question or speculation about the origin of the expression. Clearly it was part of the oral language but rarely used in written form. The earliest writing which uses it in something close to the modern form comes from Pierce Egan, Real Life in London, 1821 (the first year of this periodical). Egan was a journalist who described life in London, in the language used on the streets. The particular paragraph goes:

Their attention was at this moment attracted by the appearance of two persons dressed in the extreme of fashion, who, upon meeting just by them, caught eagerly hold of each other’s hand, and they overheard the following – Why Bill, how am you, my hearty? – where have you been trotting your galloper? – what is you after? – how’s Harry and Ben?- Haven’t seen you this blue moon

(Life in London, 1821))

This depiction of London slang is very different from anything written before. Still, this particular phrase required a footnote provided by Egan, stating that ‘blue moon’ meant ‘a long time’. The expression was not commonly known, apparently. I found no earlier mention, and it is therefore likely that the expression arose in London slang shortly before 1820.

The suggestion has been made that it developed from an earlier expression ‘once in a moon’, with ‘blue added to describe something much rarer than monthly.

Nothing older?

There is a much earlier mention in a document from 1528(!) but the meaning is so different that there does not appear to be any relation. It appears in a tract called Rede me and be nott wrotke, For I faye no thinge but trothe. written by William Roy and Jerome Barlow (but attributed to William Barlow who admitted being the author a few years later, when he tried to retract this rather unpleasant document.) The mention of ‘blue moon’ (in an inaccurate spelling for ‘blue’ even for those days) is in the following lines:

Holdynge the worlde vniverfall.
Agaynfl god they are fo flobbourne/
That fcripture they tofle and tourne/ ‘

After their owne ymaginacion.
Yf they faye the mone is belewe
We muft beleve that it is true

(where the ‘f’ was used for the modern ‘s’). The text says that these are people who hold themselves above the world, god and scripture, and they think that if they declare the moon is blue, we should believe it. So in this context a blue moon is make-believe. It is just not true. This does not seem related to the later meaning of a ‘long time’.

It appears that this use of ‘blue moon’ never caught on. It did not become adopted into the English language until it was re-invented in London, 300 years later, now with the meaning of a ‘long time’.


What happened after 1820?

There are few mentions in British books. For instance, 1860. F. W. Robinson, Grandmother’s Money, I., 144, contains the line If he talked till a blue moon. In 1869, Edmund Yates published a book ‘Wrecked In Port’, a purported autobiographical account of a shipwreck survivor. It includes:

These gentry, who would have sat interested for that indefinite period known as ”a blue moon,” had the talk been of markets, and prices, and ” quotations,” at length thought it time to vary the intellectual repast, and one of them suggested that somebody should sing a song.

Other occasions are in 1876, Mary Elizabeth Braddon, Joshua Haggard’s Daughter, x.\iv. Why should she stint as to one or two puddings a week . . . and a fruit pasty once in a blue moon (This is incorrectly listed as an unidentified book from 1871 in some articles on the blue moon), and in 1884, Robert. Francillon, Ropes of Sand, xxi. says: I’ve made bold to take the chance of your being at home for once in a blue moon, Mr. Carew,’ said she..

The expression survived, was in common use, but was not particularly common. All four authors lived in London, confirming an origin from London slang.

The expression resurfaced in North America. Blue moons had been seen there as wekll, following the Krakatoa eruption in 1883. A letter witten Jan 22, 1884 appeared in the Feb 1 issue of ‘Knowledge’ (an American periodical appearing between 1892-1911) stating:

There is a very old Norfolk saying, once in a blue moon. Can it have had its origin in the actual and yet very infrequent observation of that phenomenon? Or is it a mere random shot at an illustration of rare events? The moon here in November was of the intensest sapphire blue, the perfect clear sky looking rather slaty. This morning at 6:30 there was a fine sky-glow, and so last week. It certainly appeared to come from aqeous vapour. (taken from Wilson, 1946).

This is from Norfolk in Ontario (not the UK), an agricultural area attracting immigrants from poorer areas in the UK: Scotland, Devon, Cornwall, amongst others. The text shows that the expression was already old and well known, but also that the origin had been lost. It is also found in the Maine Farmers’ Almanac (a publication that existed from 1819 until 1967). In this almanac, and for the first time, it was given a specific definition. There is a long tradition in North America to give each full Moon in a year a name. Examples are hunter’s Moon (October) harvest Moon (September), lenten Moon (last full Moon of winter), and Easter Moon (first full moon of spring). Different names were used in different regions. Each season should have three full Moons. But some years have 13 rather than 12 full Moons, and in those years there is one season with four rather than three. This throws the naming out of kilter with the agriculural year. The almanac used the term ‘blue moon’ for the third (not the fourth!) full moon in a season of four. It is not clear when this was first used but it was in use by 1915 and may go a long way back. An article describing the detective work involved appeared in finding this obscure source is in Sky and Telescope in 2006.

The custom to give names to full Moons was used mainly in North America, and mainly in rural areas (where working outside at night becomes possible only with a full Moon). Therefore, this specific definition may well come from Maine or from a nearby area. The date is unclear, and neither is it known whether there is an oral tradition behind it or that this definition was invented by one of the Almanac editors.

The 1937 issue of the Almanac explains the procedure (reproduced here):

However, occasionally the moon comes full thirteen times in a year. This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar. It became necessary for them to make a calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason thirteen came to be considered an unlucky number. Also, this extra moon had a way of coming in each of the seasons so that it could not be given a name appropriate to the time of year like the other moons. It was usually called the Blue Moon. There are seven Blue Moons in a cycle of nineteen years. This year (1937) has a Blue Moon in August the same as 1918. In 1934 and 1915 Blue Moons came in November. The next Blue Moon will occur in May 1940 as it did in 1921. There was a Blue Moon in February 1924. In olden times the almanac makers had much difficulty in calculating the occurrence of the Blue Moon and this uncertainty gave rise to the expression “Once in a Blue Moon.”

This 1937 article includes a fair amount of unproven speculation. It was indeed the task of the priests to keep track of the calendars, and already in Jewish time they would order the insertion of a 13th (lunar) month when the seasons and the lunar calendar had clearly gone out of sync. Under the Julian and Gregorian calendars, their role was limited to the ecclestical year. But there is no evidence that in medieval times the extra lunar cycles were called ‘blue moons’, or that full Moons were given names. Neither is there support for the claim that the Almanac was the origin of the term “Once in a blue moon”. What is clear is that this expression was well known in 1937, but that the origin had been lost.


Modern times

The definition changed again in 1946, this time through a mistake. An article in Sky and Telescope tried to answer a reader’s question on the definition of a blue moon. The answer was based on the usage in the Maine almanac, as explained the 1937 article, but the author misunderstood the explanation. He believed it was used for the second full Moon in a calendar month. The magazine repeated this altered definition in a 1950 article. It resurfaced in a 1980 radio show, became incorporated in a Trivial Pursuit question, and from there made it into modern ‘knowledge’. The article in Sky and Telescope which explains some of this history is apologetic in tone, but does not retract the new definition. How could it, if it had become part of Trivial Pursuit?

The earlier definition was much more useful, though. the Almanac defined the seasons as starting at the solstices and equinoxes, using a mean motion of the Sun (correcting for our elliptical orbit with its varying speed). These are moments in time everyone can agree on. The new definition depends on location. A full Moon may occur on different dates, depending on the time zone. For instance, in 2018 there will a second full moon within a calendar month on January 31 and again on March 31 (unusually close together, thanks to February having no full Moon). But this is not true worldwide. For instance, in New Zealand, these full Moons wil occur on Feb 1st and April 1st, and according to this definition, neither will be ‘blue’.

How often does a blue moon occur?

True blue Moons (or Suns) are rare. Regions with frequent dust storms may see it more, but areas which depend on chance smoke from the right kind of fires or ash from just the right volcano may experience it perhaps once a century.

The other definitions give more frequent occurences. Full Moons are 29.53 days apart, and the average length of a month is 30.43 days. Some months are longer than others, and have a higher chance of a second full Moon in one month (February, on the other hand, can never have two and occasionally has none). The time between two full Moons varies through the year, from 29.27 to 29.83 days. Steve Holmes (2011) put this together and found that each month has a chance of 3.28% of ‘being blue’. A second full Moon in one calendar month can therefore happen on average once every 30.48 months. The next occasion will be Friday, July 31, 2015, and this one is worldwide.

(The second full Moon in December 2009 coincided with a lunar eclipse, so for a brief moment the Moon was both red and blue simultaneously!) (From Steve Holmes, 2011 ).

A lunar year of 12 full Moons is 11 days shorter than a calendar year. Each calendar year therefore has a 36.3% chance of having a 13th full moon. This will happen on average once every 33.0 months. The next one will be Saturday, May 21, 2016. This will be by definition worldwide.

Grounded in astronomy?

In conclusion, the expression ‘once in a blue moon’ does not come from astronomy, nor from volcanology. It was a London colloquialism, dating from before 1820, but there was no observation or definition behind it. The suggestion that id derived from a medieval tradition, related to the ecclestical lunar calendar, has no supporting evidence of which I am aware. Instead, the astronomy was added later, perhaps by an editor of an American almanac (which sometimes were astronomers), and redefined in a popular astronomy magazine. Astronomy adopted an orphaned expression and gave it a new home.

copyright: The University of Manchester

153 thoughts on “Once in a Blue Moon

  1. Thanks for the post! Now how shall I answer the question should I find myself playing Trivial Pursuit?

    I thought perhaps to add to your through narrative by exploring the cheese aspect of the moon. I was going to say something silly about the moon being made of blue cheese. But it isn’t. I discovered that it is made of green cheese. So then I had to explore that further.

    I wouldn’t be surprised if the (Londoner) John Heywood’s Proverb “The moon is made of a greene cheese” (1546) could have played a part in the origin of “blue moon”. The “greene” here refers to the age of the cheese (young, new), not the color. (For more details, see http://en.wikipedia.org/wiki/The_Moon_is_made_of_green_cheese)

    How might greene cheese compare to blue cheese? Blue cheese is an aged cheese.
    Green = young = naive, will believe that the moon is made of cheese.
    Blue = aged = wise.
    I don’t think blue cheese was rare in general in England, but I’ll venture the guess that it wasn’t commonly available to “the masses”.
    How often would one meet a person who is considered exceptionally wise? As rarely as one could enjoy a good blue cheese?

    If you can follow my train of thought, then you will understand my conclusion:
    There is a possibility that a blue [cheese] moon was the opposite of a green cheese one.

    It seems as good as any other guess as to the pre-1820 origin of the phrase … 🙂

    • Well, from a vocanological perspective. The Lunar regolith is pretty close to the composition of Earth’s mantle and crust. The idea is that when Thea impacted, the Earth kept the core material as the lighter blasted off crust coalesed into the Moon.

        • My mother always went by the Farmers’ Almanac definition of “blue moon”…but it never made sense to me since a blue moon by those terms was usually just as greenish as any other moon of the year.

          Now the cheese-mythololgy resonated more with me. The greenishness of the Moon coupled with the craters gave the impression to kid-me that it was a large ball of Swiss cheese similar to many I had seen in our refrigerator…covered in a fine green dust. (Yuck!)

          But Geolurking above brings up an even more interesting point and a whole new musing that the mind of kid-me would have run amuck with. Maybe the moon is a big green olivine-rich olive…and the force that causes the moon to always face the earth is the huge pimento sticking out from the dark-side. 😀

    • I knew about the Heywood’s expression but to me it didn’t seem related to the blue moon. The meaning would have had to change too much., and there is no record to a blue cheese moon in
      the old literature.

      This post was a bit far the normal topic of this blog! Maybe in the future one on Krakatoa. But the next post should probably be back to Bardarbunga.

      Be aware: writing posts can seriously damage your health. I have caught a bad flu and have been at home with fever for several days – no improvement yet. (‘VV’hen: volcano virus.) It makes life rather boring. :

      I sit at the window sill
      kept home in rainy weather
      I wish i was two little dogs
      Then I could play together


  2. I like this post. I use this phrase sometimes. Later I found out that sometimes a blue moon is on my birthday which is at the end of a month. I read part of the post but I need to get some sleep. I’ll be sure to finish reading all of it later. 🙂

  3. Thanks for the interesting post Tom-Helge Andersen. Glad to see continuing activity on this site. And thanks for putting the new link at the bottom of the comment page where everybody who is looking at comments usually ends. Several recent new posts were announced at the top. Since refreshing comments goes approximately to where last comment was made it is easy to miss the link to the new post.

  4. Thank you Albert! That’s fascinating! I love to find out the origins of phrases like this. It’s amazing how quickly an explanation for an expression can be taken as truth by the majority. Also how quickly an expression can change meaning. I live in Wiltshire where locals (particularly round Devizes) are called Moonrakers. When I first heard this expression (back in the 1950’s) it meant that the locals were a bit dim in the head. The story then was that a man passing a village pond at the time of a full moon saw some farm labourers raking the water. He stopped and asked them what they were doing and they said they were trying to rake “that gurt [great] cheese” out of the water. This was a sign of the simple-minds of agricultural workers. Much of Britain’s history was revised in the 1960’s and now the explanation is of local people out-witting the local Excise Men. The story now goes that locals were smugglers and had hidden their stash (probably rum) in the pond. The local Excise Men found them but they pretended to be daft and raking for the “gurt cheese in the water” so they were let off. 🙂

  5. I don’t know what it is about wordpress / things that people share (hello, GeoLurking 🙂 ), but my browser is constantly (re)loading this blog. Any suggestions for me on how to get it to drain less bandwidth (other than loading it myself on an as-needed basis and closing it afterwards?)

  6. Oh Albert! I now feel so guilty. My comment about my memory of seeing a blue sun and moon led you to your sick bed!
    Thank you so much for this post I have copied it and have printed it out for my Grandchildren.
    So much research has gone into it. It must have taken much of your precious time and I really appreciate it.
    I do hope you are feeling better very soon ((((((Hugs)))))))

  7. I found this beautiful clip showing the sun’s plasma through colour filters. nearest to a blue sun I could find on you tube!

  8. OK! Really on topic now……..Blue lava 😀 😀 (Sorry about the irritating “music”). Can’t sleep……Had an SOS call from Aunty Doris who had fallen……Just staying up for a while to make sure she’s OK . Luckily she didn’t go down too hard and got stuck on her knees.

    • Thanks for that Diana, again one of your posts has brought a rush of memories for me. lol. I climbed down to the bottom of Kawah Ijen about 5 years ago when I was almost 70. The climb down is a bit dicey in a few spots and at least one person has been killed when doing a descent. Suphur was not burning at the time but it was necessary to wear a water-wet cloth rag over the face as the dense fumes are full of SO2 and also some HF. When the wind would shift and put you in the plume, you needed to move out of its way as the SO2 was very concentrated. The workers extracting sulfur from the vents have an average life time of 25 to 35 yrs due to constant exposure to poisonous gases and probably especially the HF. The workers would carry up to 80 kg of elemental sulfur up the steep trail to the crater rim and down to a sugar mill. The sulfur was used to bleach the sugar (as the dioxide, SO2)

      The lake at the bottom is one of the most acidic lakes in the world containing sulfuric acid with a pH of 0.5. People have gone out on the lake in rubber rafts to take samples for analysis. An aluminum boat, launched in this lake, would dissolve in fast order with a great rush of hydrogen gas.

      The workers warned about “black sulfur” that would occasionally appear and was prone to auto ignition.

      The miners extract about 14 tons of sulfur a day representing about 20% of sulfur emitted/day. They believe that when the lake is filled with sulfur the volcano will erupt again.

      • WoW! Biologique! What an exciting life you lead. Can I ask? Did you do this descent just out of interest? I am afraid I would have thought twice before doing it! But then I am not very brave 😀
        Those poor workers. 😦 I feel so very lucky in my life.

        • I have had a life long interest in volcanoes since young and collected stamps including beautiful triangular stamps from Nicaragua. These stamps often featured different volcanoes of Nicaragua which I found very exciting – a must see. Last year we traveled for 6 weeks by local bus and small river boats through Costa Rica and of course Nicaragua which is full of active volcanoes. Visited quite a few active volcanoes, one of which (Poas), had a minor phreatic eruption a few weeks after our visit.

          My wife had polio and can not do some of the difficult stuff. she leaves it to me to bring back photos so she can share in the beauty of difficult areas. On our wild and woolly trips she carries canes to help her walk although she does not ordinarily use them at home. She is even more addicted to travel than me.

          Re the descent into Kawah Ijen, quite a few tourists, usually on the young side, go down the very steep crater wall to the bottom. It is not a particularly difficult hike. A great chance to see and experience chemistry at work, cough, cough, cough – lol. Definitely not a good place for people with asthma.

          And yes, I felt great empathy for the workers who are caught in a horrible cycle of life-shortening work just to support their families. Many had ulcerated sores on their shoulders from carrying such heavy loads on bamboo yokes. It was very sad to see and made me feel guilty visiting the area just out of curiosity and interest – when they had to do it to survive.

        • I just thought about it, if you are interested, send me a private message with your e-mail address and I can send you a couple of our trip reports. I do not post these reports openly on the internet.

  9. And on a more disturbing note. New York is soon to get hammered with snow. DeBlasio has been on TV hyping up the danger quite well. I seriously doubt it, but there is a very small possibility that I could loose connectivity to the Cafe in the event of a network outage. The likelihood is quite small when you consider the redundancy and robust routing algorithms that are built into the Internet. After all, it was designed to maintain connectivity in the event entire sections of it were destroyed/vaporized.

    • Yeah, they are sure hyping it alright. “This could be a storm the likes of which we have never seen before,” said New York City Mayor Bill de Blasio at a news conference Sunday. “A crippling and potentially historic blizzard,” the National Weather Service said.

      OK, but I grew up where 2-3 feet of snow was a big storm, but nothing special, other than I was excited to get enough snow to make tunnels. I don’t recall my mother ever rushing out to buy groceries or candles or batteries, we just assumed we had all that on hand. My mother never once drove us to school (which was only 3 blocks away), we just walked anyway. I don’t recall school ever being closed for weather. I guess I sound like an old codger!

      • I’ll join you in the Old Codger’s team.
        Here in the UK we have a new phenomenon called “A weather Bomb”….
        We called it a storm or Bad Weather,
        We always had enough dried food and tins n store to “see us through” a week or so of bad weather or emergency. (I still do this)
        Recently I noticed that weather alerts cover gales and weather I expect in Autumn and winter. I think now the met Office could be sued if they didn’t accurately forecast warnings of possible floods or wind damage. Don’t get me wrong. Warnings save lives but now there are warnings for weather that is not so extreme.
        This is so sad as it seems to have taken away the ability of the average person to actually take some responsibility of listening to marine forecasts and understanding weather charts, looking at the sky, learning about weather and accepting that nature throws crap at us sometimes and dealing with it. (These comments are for the UK. We are Islands. We get Atlantic storms)
        We had a centimetre (a couple inches) of snow last week. It melted. There were no snow drifts. Still the country got a little disruption! Still there were dire warnings. Still the panic in the air!
        The Good Lord help us if we get weeks of ice and snow as in 1963 or 1947.
        Interestingly back in the 1940’s & 1950’s my Grandfather always prepared for snow when he heard on the news that New York had been hit with severe snow storms. He told me “We always get their snow three weeks later”.
        I shall watch this with interest 😀

        • Out in the high lonesome of NE Oregon we are 12C today and could have most of the week at 8-10C . no cold or snow in the 10 day outlook..
          Out doing garden work today when I ought to be chopping wood-normally…
          El Nino…

          • Seattle’s in the 60’s (F) —I have been rushing to finish pruning my fruit trees before the buds start swelling. I saw flowering ornamental trees when I was driving around yesterday—at least a month early.

        • Oh Diana I do agree with you. The whole Met Office forecasting has become a farce full of dire warnings. If we are to take heed of a “Cold Watch”, we have also to be warned of a “Heat Health Warning”. I shake my head in despair and advise folks there’s a yellow weather warning of severe drizzle in place. The sad thing is, they believe it is true. Meanwhile I just chuckle about “Yellow Rain” and go about my daily business ignoring anything other than the Atlantic pressure chart – the source of truth. The only time I do take an interest is when alerts go out over thunderstorms. Now they are interesting to me!

          • yay:) I am with you on all this 🙂 I love the yellow drizzle warning 😀 😀 It’s a bit like the man who phoned the met office and complained he had just shovelled several inches of Mainly dry with sunny periods off his driveway 😀

    • Well, a more realistic look at it shows that if it gets above about 32″, then there is something to fret about. That’s getting up into Black Swan territory for New York snowstorms.

      The Odds based on historical data from http://www.weather2000.com/NY_Snowstorms.html
      More than 21.71″ One in 3.15
      More than 24.97″ One in 21.98
      More than 28.22″ One in 370.4
      More than 31.47″ One in 15,787.2
      More than 34.72″ One in 1,744,277.9
      More than 37.98″ One in 506,797,346

      The “Typical” New York snowstorm is 16.6″ to 20.25″ at the 99% confidence interval. If they are already prepared to handle that, then the extra bit should not come as much of a surprise in dealing with it.

    • Wish we in Western Washington/Cascades could get some of that snow! I would gladly trade the high temperatures we are experiencing for some snow to build up our snowpack. (Highs in the 60s and 70s. That is summer weather for us!)

  10. Picked a good week to go to Florida, home is well south of NY so not expecting a lot of snow anyway but sunny and 60 here.

    • Several years ago, as a firefighter preparing for initial entry on a housefire, I was held up outside the front door trying to get a knock down on the fire in the living room. By the time I ran through my first air-bottle and headed back to change it out, I was encased in what felt like suit armor from the frozen water on my turnout gear. Some of my cohorts got in trouble for leaving a small corner of the building burning so that they could stay warm. This section had already been burnt away from the building and amounted to nothing more than some framing and debris. I think that was back in ’93 or so in Florida.

      As a rule, Florida is far worse equipped for icing road conditions, yet last year we did pretty much okay. They per-emptively sanded a few vulnerable bridges and issued the appropriate warnings. Things occurred quite well with little disruption. My dog was a bit put off because the grass crunched when he walked on it… and the two smaller ones wouldn’t have anything to do with it so had to be forcibly put outside until they did their thing.

      Note: How I got wet. A panel of sheetrock in the ceiling flapped down in front of me fully obscuring my vision and causing the water to bounce right back at me. At first I thought I was making great headway and that I had it down to just smoke. Nope, that was sheetrock.

      • You think you got trouble with your dogs and bad weather? Poppy the large Lurcher has it in her small brain she will dissolve if the rain falls on her. Large muddy puddles are not the same as rain or warm soapy water. Poppy weighs more than me and impossible to throw out!.
        The trick is to shut the back door on her quickly and , when she faces the decking steps down to the yard, to get behind her and …..SHOVE!

        • It’s no the water that bothers to two rat dogs, it’s the thunder. They cower under me when it happens… like I could do anything to make it stop. The funny bit is that any other time, they hover near my wife and suspiciously glare at me when I come into the room. A bit of thunder and they they quickly seek me out. The creature… well, he couldn’t care less and loves the water. This summer, I am going to see if he still chases and snaps at the stream from the water hose.

  11. So the gas plume seems to be perking up again.

    and live lava is still appearing at the head of the flow.

    I have been wondering how much water is leaving the Svarta at the moment, are any of our Icelandic contributors able to comment?

  12. I notice that there are recent EQs following the initial line of the movement out from Bard. While sequentially this might be ripple-through from the linear activity a few days ago in the Tungna region, I have to admit it could also be generated by the dyke closing up.

    Big Sigh.

    I won’t let go of the hope that we’ll see “live” lava when we are there, and hopefully from something comparatively safe like the fissure (vs., say, Hekla).

    I read that in 2012 there were 600,000 summer tourists to Iceland. (No, I don’t remember where I read that.) So here’s to hoping there isn’t populated-area major eruption during peak season.

    • “…here’s to hoping there isn’t populated-area major eruption during peak season.”

      If you compare this map (http://en.vedur.is/earthquakes-and-volcanism/volcanic-eruptions/) with one that shows the populated areas, you’ll notice that most of the volcanoes are in the uninhabited (and ?uninhabitable) Highlands a long way from where people live – unlike Vesuvius and Naples.

      Of course, a major ash discharge could affect much of the country, and a jokulhlaup from BB, especially down Kaldakvisl and into the Tungnaa, could very well affect power supply to towns and villages in the south. But Icelanders are an admirably hardy, canny sort and their HEP stations have been designed and built with jokulhlaups in mind.

      • Or you could look here http://en.vedur.is/earthquakes-and-volcanism/earthquakes/ (which will get updated, but I don’t think that will matter) to see that the entire MAR has little bubbles of earthquakes. When this started there were always a few, but usually only a few, outside of the Bardarbunga – Holuhraun area. Now there are noticeably more than a few every day. It may very well mean nothing, but can anyone pinpoint the eq that broke Barda’s magma chamber?

        I was thinking specifically of Hekla and the eruption that should have happened after Eyjafjallajökull but didn’t. Vik is a place tourists & tour buses stop while driving the Ring road, Activity up north could impact Akureyri, which will surely be housing more tourists than locals.

        It doesn’t hurt to hope nothing like that happens. Even Iceland is likely to have a difficult time handling 2-3 times the normal population and panicking tourists trying to get out of the area — and having no place to house them in other cities.

        • I’ve been watching the earthquake pages you linked to for several years. The current distribution of eqs outside the BB area is not unusual; if anything, there are fewer M3+ elsewhere than usual. Not every eq is associated with an eruptible volcano. As for which eq broke BB’s magma chamber – well, I’m no volcanologist but I’m not sure it works quite like that.

          To be honest, I think that you are over-dramatising the whole thing and getting things out of perspective. Those 600,000 visitors aren’t all there at the same time. Iceland *is* an adventurous destination, so if you are worried now and spend your whole trip with worry in the back of your mind, influencing your decisions, don’t go. There are more comfortable places to go if you want to see fumaroles and fresh lava.

          As I think I mentioned in an earlier post, 2 years ago a friend and I walked from Nyidalur through Vonaskard (ie 5 miles from BB), and then SW roughly along one of the routes that a BB jokulhlaup could take, ending up at the south coast. We were self-sufficient for 16 days, camped on the bed of a former lake emptied by the 2011 Hamarinn eruption, walked – and occasionally slithered! – over glaciers, waded through quicksand, trudged seemingly endless sandy desert, climbed volcanoes, got lost in dense fog, were sometimes soaked to the skin, for the first week we saw no sign of another human – not even footpaths, maps were unreliable, I nearly broke my hip… I could go on. The point is that we had a wonderful time precisely because we knew that we weren’t completely in control of events; we knew that we were walking though one of the most volcanically active areas in the country. Contingency is the name of the game. We planned carefully and took proper precautions… That’s what any sensible traveller does.

          Would you rather die having spent your whole life in a woolly blanket hoping that nothing happens, or would you prefer to have accepted contingency and lived with all the freedom that God gives us? That’s how Icelanders live.

          • Leslie, travelling in Iceland is not as scary as it seems, regarding volcanoes.

            In fact, last few months there have been countless tourists travelling around Iceland and they were seemingly unaware that the biggest lava eruption of the century was happening just some couple of hours from then. These tourists also never knew about the gas pollution. I frequently host tourists so unless I would have told them, they wouldn’t know about the Holuhraun eruption. Now, this is one side of the story. To show you that most eruptions in Iceland are harmless, as tourism continue as business as usual.

            Now, the other side of the story. Every year countless tourists get into trouble, and several have died, because they often took irresponsible risks. Most often people go hiking to mountains, unprepared (or they think they are, but they are not) and then the weather turns very nasty, which it does in Iceland at times. So, am57, “getting lost in the fog” can be sometimes a very bad idea. The worst is usually only outside of summer months, when snowstorms can kill you if you are unprepared on a mountain. Another related risk is slippery ice. Lack of crampons has lead often to deadly situations which could have been avoided. But even normal steep ravines are particularly dangerous in Iceland. Finally, river crossing – usually it is just fun both for hikers and for jeeps – but when they are swollen, people have been known to have died doing what they thought it was easy. It requires clever accessment, which often excited tourists lack.

            Anyways, this sort of misfortunes is nearly all due to the weather. So my advice is always watch the forecast and go by it, and you will likely be safe. Iceland will be great joy for nature lovers (and volcano lovers)

            By the way, am57, which was the empty lake from Hamarinn 2011 flood? I didn’t know of that!

            In the early times of Holuhraun eruption, I camped in cold September nights, next to Hamarinn and some of BB flood paths. Obviously not in the flood path, like you probably did – it was too risky at that time when everyone was speaking about floods – actually I was high up, because I wanted to see the Holuhraun red glow far away. And you know, even in normal times, its not good to camp at a common flood path, and so close to the flood source 😉

            • Hi Irpsit,

              I completely agree with all that you say. Sorry, I probably came across as more macho than I meant to, but I wanted to try to put Leslie’s anxieties in context.

              My partner and I are very experienced mountaineers and have climbed and trekked in many parts of the world. We know what we are doing and go equipped for the conditions. I had been to Iceland twice before, so I had a sense of what to expect. The risks we take are calculated and carefully planned for.

              We ensured that the glaciers were “dry” (ie not snow covered, which conceals crevasses), we can “read” glaciers and know where crevasses are likely to be (and very good maps of crevassed areas on Iceland’s glaciers are published each year). I certainly wouldn’t advise anyone who has not done a lot of mountaineering to go on the glaciers: even if they had crampons, they wouldn’t be able to “read” the glacier and distinguish safe and unsafe routes. We were extremely cautious about river crossings and learned and practiced in safe contexts both how to “read” a river and safer techniques for crossing them. (There is no 100% “safe” technique!). But we each carried a Personal Locator Beacon, just in case. For us, traversing glaciers was safer than doing some of the big river crossings (eg the Tungnaá), but for others it might be the other way round. We also carried 1:50k maps, compasses and a GPS, so although we were “lost”, it was only for a few minutes. We had the gear to get us out of the situation, and we knew how to use it.

              But, when we were at Landmannalaugar we saw a lot of people with really inadquate equipment having a totally miserable (and doubtless scary) time as a consequence. People can seriously underestimate how hostile the Icelandic environment can be, even in summer. (We had a blizzard on Sveinstindur. The Icelanders we met were having a miserable time; we were fine.) And we met IceSAR people who had picked up a German with his 2 young daughters walking up the desert West of Langisjor. The only equipment they were carrying was the clothes they were standing up in and 1/2 litre of water!

              Our “Hamarinn” campsite was at 64,503644; -17.917258, I think. The GPS coordinates aren’t to hand. But those coordinates put us in the middle of Hvítalón! Another big change is that Leynidalur is now dry, presumably because of the 2011 jokulhlaup (so I was told by a German who knows more about this area than probably anyone alive); the main channel of the Sveðjá runs closer to the edge of the glacier, though we had quite a deep crossing of a smaller channel south of spot height 1105. The next night we camped at the site of what most maps show as the easternmost of three (or 4) lakes west of Kerlingar! Ah! What a wonderful time…

          • It is true that I’ve only been paying attention for 5 months, and not every day. My impressions of what might happen are based far more on an average of opinions from here and other non-newbie sources than on my own interpretation / observations.

            The piece that has me really take notice is the 120-year cycle as it is supported by enough data points to mean something. But I don’t know what the standard deviation might be and I recognize it is possible that the appearance of a cycle means nothing, statistically.

            I don’t see anything wrong with publicly hoping that nothing bad happens. I could have stated that I hope we aren’t hit by an asteroid this summer, but the odds of that are significantly lower. I can hope that no tourists get hurt, but that is a fruitless hope and largely dependant on the actions of individuals.

            I don’t mean to appear to be over-dramatizing. It is in my nature to worry about others, look at the bigger picture, see connections that others miss. These are not entirely negative traits. I really don’t know how many tourists really think about the “active” part of “active volcanic region”. I strongly suspect the percentage of them is decreasing. It can’t help but be as the # of tourists is skyrocketing:
            Even more informative is this:

            Click to access toursim_in_icland_infigf2014.pdf

            “Visitors to Iceland have almost tripled since 2000. Their number had risen to 807,000 by 2013. The mean annual increase has been 8.2%since 2000.”
            “Around 44% of visitors in 2013 came during the three summer months (Jun-Aug),” and “Foreign visitors stayed on average 10.2 nights in Iceland during summer 2011 … ”

            If I did the math correctly, it can be expected that there will be about 40,000 tourists on any one day in Iceland this summer. I am glad your comment made me take the time to find good statistics about this subject.

            Still, 40,000 is a lot of people. Too many tourists at the places we go is one of my biggest worries. I don’t like crowds. I often refer to myself as an “anti-leming”

            As for us, we’ll not hike on Hekla; there are a great many other things we can do so this isn’t any sort of deprivation. We’ll take the precautions advised as far as always topping off the gas tank, always having food and water in the car, and always having clothing for bad / cold / wet weather with us. We won’t drive on F roads on our own. We are working even harder on getting our youngest to think before acting, but this 9-year-old child only two weeks ago ran out into the driveway of a parking garage from behind a wall without a fraction of a hesitation.We *need* to worry about him because if he is seriously injured or killed on the trip I want it to be from the unforeseeable and not from something that we knew was a preventable risk.My behaviour is tailored to who he is. I’d have not worried like this when the older one was 9.

            We are who we are. The amount of planning I do for family travel has been influenced by the experience of traveling with my family. I’m honestly confused at your reactions because at first you were very supportive and gave me some great advice.I’m in the process of not being wrapped in a blanket and I am preparing for enabling the experiences my family will enjoy. The sheer act of going is taking a risk bigger than any I’ve taken in a very long time.

            • Hey Leslie, all is fine.

              But you are right. The 120 year cycle is talked amongst Icelandic volcanologists. Looking back in history, yes, this cycle of Icelandic volcanism appears to be there, albeit somewhat irregular. Every time it does happen, many eruptions occur within a few decades in Vatnajokull and around, and some of them regional rifting episodes, and others historical explosive eruptions.

              I can talk more about this cycle if you want. But now I make my comment short.
              Hekla: yes, not wise to hike it up. Regarding your kids, just ask them to be care with the precipices. Stick to the more common touristic attractions which are rather safeguarded with cords to limit tourist access to danger areas. Go a lot to natural hot tubs (they are cool and kids love them). For touristic volcanoes, I recommend Krafla and Krisuvik, you can drive into them, and visit the geothermal areas with some safety paths. Hiking? Skaftafell in the southeast is very touristic and safe. I think your kids will love the hollidays, but yup, carry food and warm waterproof clothing for them. If you have the money, even go for a flight above Holuhraun, it is safe (even for kids), and a quite awesome adventure.

            • From my far more limited experience, I’m with Irpsit. The Golden Circle, Myvatn/Krafla and vicinity, Skaftafell are all superb areas which cater well for tourists who don’t want to be too adventurous.

              I suppose one of the things I’ve learned through mountaineering is to keep the risks in proportion relative to other risks that you take in the normal course of life (eg gun crime, traffic accidents) and to calculate accordingly. The general risks in Iceland are on that scale relatively low – unless you seek out higher risks.

              OK, there may be a massive explosive eruption, but so long as you’re not within the danger zone of Hekla there’ll be some warning, so you’ll be able to evacuate. Even in popular but remote areas in the vicnity of Katla and Eyafjallajökull there are signs showing emergency warning signals, escape routes, etc. Not all 40,000 tourists will be near an erupting volcano (that was why I posted the map earlier), so they won’t all be trying to move away by the same route. And think of the size of the exclusion zone around BB. If an eruption looks imminent, you won’t be able to get into an area where you are likely to be seriously affected or, as in the case of a BB eruption affecting power suppies, contingency plans aren’t in place.

              So my comment about woolly blankets was about taking an informed rational approach to risk. Having done that, you may still decide that Iceland’s not for you, but if that’s your decision, that’s OK. I probably wouldn’t do the trek that I did by myself, but I know someone who would: we each calibrate risk in a way that is partly relative to what we know of what we are willing to take on. What’s folly for one may be reasonable for another. Respect accrues to making the subjective calculation rather than to the “objective” danger of what you’ve taken on.

  13. The western Washington weather is lousy if you are a skier like my wife and I are. Our Wednesday ski bus has been cancelled for tomorrow and it does not look good for next week. No serious precipitation in the forecast. It would take a 1 to 2 meter dump to make the slopes skiable. The area we go to is not running some of the lifts and have reduced the ticket price due to low snow coverage. Last year started like this and by mid February we were 10 inches behind normal rainfall for the year. Our hiking group was hiking places you normally could not get to the trailhead. From mid February to the end of March things changed and my area ended up 10 inches of rain above normal and the skiing was great.

    • Oh My! Looking out into the cold night here in NW England looks like you should bring your skis over here.
      Howling wind and white stuff falling. I am glad I am inside!

  14. It looks like the data for the volume of the eruption (1.4 km3) is quite thorough:

    and the 1.8 km3 estimate for the caldera displacement is based on this:

    Thanks, IMO. Nice data.

    • Very much so. Thanks for the linkage. 😀

      Personally, I have been dealing with what is either a statistical anomaly, or I have lost my touch. The probability of being shipped bad parts is to me, quite phenomenal. It works similar to the dice analogy.

      Probabiliy of rolling a six on a single six sided die → 1/6.
      Probability of rolling a six on two consecutive tosses of one die → 1/6 x 1/6 = 1/36.
      Three tosses, six each time → 1/216.

      Either the manufacturer has developed a serious quality control issue, or something is wrong with me. When you are dealing with failure rates measured in faulty units per hundred thousand or so, the odds get astronomical very quickly of getting consecutive bad units. My knowledge of how the numbers work make me worry about my ability. After all, I am the common denominator in all of this. I do know that I had a small stoke a few weeks ago, but all other indications point to me still having the ability to follow a train of logic while troubleshooting.

      • Lurking could it be Murphy’s law at work? I am sure it’s not you. I understand your stroke was not a very bad one but bad enough. A stroke may affect your motor neurons but I am pretty sure your intellect is not affected that much if at all. That is what makes strokes so awful. The fact that in bad cases the patient’s awareness and faculties are OK but the ability to communicate makes it a hard ailment to cope with. The carers may think the patient has lost their marbles too and treat the patient accordingly. I can think of nothing more frustrating.
        As you are really into physics maybe this may explain you present problems 😀 😀 According to this reasoning Murphy’s law is not possible but it does explain why things may not go according to your plans. 😀

      • Well, I take solace in that picture of the dryer with the neatly folded clothes and the admonishment that according to the law of infinite probability, that this should eventually happen. I’ve worked on some pretty complicated stuff in my time, and am still mostly confident in my abilities. To hedge my bets, I even kept a more senior tech on the phone and walked through the troubleshooting steps with him so that he would know that I was not making mistakes.

        I do like your mention, or at least linking to something regarding “Sod’s Law”. In fact, we have archaeological evidence that it has been with us for a long time.

        The Laetoli footprints show an adult taking shortened steps as they walk, probably holding the hand of a youngster across a muddy ash deposit. Probably leading the kid to safety. As a fellow hominid, you can mentally put yourself in their place as you resign yourself to the trek that has to be made to get your children out of harms way.

  15. My Wife: “Don’t give him anymore to eat”
    Me: “Why?”
    My Wife: “He just threw up all over the place”
    Me: “What did he eat?”
    My Wife: “I don’t know”
    Me: “Was it a cat?”
    My Wife: “No”
    Me: “Good, I don’t have to call the neighbor”

    • My Springer is a lover of cats. he was raised with them and will not
      chase one unless he knows it to be a threat to his large rubbery nose…
      However, there is a learning curve…..
      Ears lowered, teeth exposed , hackles up, does not mean “Kitty wants to

    • I fear that “The Creature” will soon learn to scale the fence. He is not fond of squirrels and I’ve seen him about halfway up the fence going after them.

  16. The Earthquakes are slowing down really fast now. I’m very glad that she did not have a major explosive event

    • From historical evidence, even in slow and drawn-out effusive eruptions, caldera collapse has historically occurred at the tail end of an eruption phase. So despite the fact that the effusive end of the eruption may be coming to an end, this doesn’t preclude a caldera eruption event, and by some evidence, it may be more likely now than ever that we would see such an event.

      -Mikayejima had a somewhat effusive sub-sea eruption in 2000, which led to a caldera collapse approximately 12 days later (See link below).

      Click to access 24.pdf

      -Fernandina (galapagos) had an effusive eruption in 1968. At the tail end of the eruption just under a month later, the caldera collapsed.


      -Askja, probably the best example of comparison to Bardarbunga, had a similar rifting fissure eruption to the current Bardarbunga episode (except it was smaller) in 1875, which went on for a few months. Not too long after the conclusion of that rifting event, Askja erupted a VEI-5 event that resulted in the current Öskjuvatn Caldera.


      Given, there are many cases of effusive eruptions where there is no collapse event, and I would imagine this to be especially true in Bardarbunga’s case. Also, there comes the questions of chicken vs. egg. Did the caldera collapse event trigger the end of an eruptive phase, or did the end of an eruptive phase trigger the caldera to finally collapse? To me, it seems more logical that the caldera events triggered an end of an eruption itself since it would level then become an easier release valve for magmatic pressure as opposed to a fissure.

      • So, statistically speaking, when should I hope for the fissure to stop so that in the first 2 weeks of July Bard will either have not have started doing her thing yet or is sufficiently over it so that helicopter tours will be allowed? (Of course I know this is purely hypothetical and not real-world. Yet someone might enjoy trying to answer it 🙂 )

        Perhaps if Bard has done whatever it is she is going to do and is over it, then the entire area will settle down and I’ll be more likely to get to Askja?

        It is looking very much like we’ll start our stay in Iceland in Akureyri and be there 5 nights then fly to Reykjavik and stay in Hafnarfjordur the rest of the time. We’ll stay in an owner-rented apartment in Hafnarfjordur right on the harbor; I haven’t booked yet but the owner is very encouraging and I’ll book once I’ve been able to book someplace in Akureyri — I’m waiting to get answers from the Icelandair hotel, which seems to be the only one available that can accommodate us with the boys in a separate room. Then the flights (which are currently still available.) I might have the hardest parts booked by this time tomorrow!

        I have to figure out how to plan the day trips so that we can get close to Askja if that is allowed, but have something else to do in the NE if it isn’t allowed, taking the same general amount of time. If it isn’t allowed to get get anywhere near Askja, I might prefer to do a helicopter from Reykjavik, maybe landing somewhere that is allowed so I can see the terrain from the ground, rather than bump over roads to get sorta-close. … I’d love advice on not-to-strenuous but also not-too-popular things to do in the Akureyri area. I don’t think we’ll rent a car, but we could if that works best for us. I can also find a custom minibus tour.

        Oh, and it is 75 degrees F here today.I don’t look forward to our summer.

          • Indeed. Krafla/Myvatn area (to the E of Akureyri) is superb, and your boys will, I imagine, love Dimmuborgir. Can you get in at Reykjahlid (?sp, and the last letter is eth)? It’s a lovely place to chill with plenty to do.

            • looking in charmap using arial font I see that
              holding down alt typing 0254 on the number pad then releasing alt gives þ
              and a capital thorn is alt with 0222 Þ

            • Thanks. I was just being a bit lazy. I have an Icelandic keyboard on my computer (it’s a Mac) but it’s a few clicks away and possibly fewer than º€∞¢ (= alt 0254 on my keyboard) and more difficult to remember!

              OK: Hótel Reykjahlíð, or do I mean Hótel Reyníhlið? Not sure, never stayed at either, but one is reckoned to be better than the other.

        • You wont see much of the south coast based in Hafanofjodur/Reykjavik without a lot of driving. Selfoss area is a better base to for day-long drives east to Jokurlsarlon, and ferry out to Heimaey, and still leaves Rekjavik Blue Lagoon within easy access.

          • I thought a lot about staying in / near Selfoss, especially as we’d rather have views of nature and not of city buildings. I decided on Hafnarfjordur because we have to feed two gluten-free people, will surely need to be in Reykjavik early for some of the guided day trips, and I found a place that has a nice view. We are likely to drive along the south coast on our own, but not all the way, and on a different day take a local flight to Hofn in order to see the area around there. I’ve finally been in contact with an agency who can either book pre-designed tours or create small van tours according to what we want. They had darn well better be able to tell me how much time it usually takes to do various things (for a family like ours) and help me make decisions. … Assuming they manage to keep breathing under all their heavy workload.

            The reason we’ll start in Akureyri is because the place I’ve selected in Hafnarfjordur won’t be available for the first few days of when we’ll be there. Although I could cut the trip shorter and arrive later, it seems like a great opportunity to spend more than one day in an area. We could pick a different area for those days, but NE is definitely a region I’d hoped to view / do more than one thing, especially if I can get in towards Askja. (There is a 14-hour day tour from Akureyui to there … It is possible …)

            This is hard work. I will be ready for a vacation when I’m done with all the planning!

            • Might be a very good idea to prebook car hire in Akureyri. Its a tiny town by UK and USA standards. And prebook van trips. Five days there without transport would be sooo boooooring ! I very much doubt tis possible to turn up and hire on arrival there.
              Self-drive to Askja would need 4×4 and it would be a very long drive from Akureyri. Its about 4 hours after leaving the ring road using the road that does not involve fordinga river. And a couple more from Akureyri to get to the start of that road. So thats 12 hours driving. The day may be long but…. I would look into sight-seeing sights from Myvatn airstrip. Myvatn is around two hours main road from Akureyri.
              With a two-week car hire you could drive Akureyri to Reykjavik staying at Stikkisholmur. You’d see so mcuh more than flying.
              Do try to get to Heimaey – the 1973 erution there neary desroyed the town and its port.Short flight eg from Selfoss strip or Reyakjavik.

            • I have not had to craft a gluten-free diet myself; but can’t you do it in the short-term simply by eating potatoes or rice, which are commonly available? Plus fish/meat/vegies. . . I am enjoying all the info about your trip, Leslie, and saving it up in case I get there myself!

          • You are so nice to worry about me and help me be sure we can have a great time in Iceland. I plan on having everything pre-booked: the cars, the local flights, the tours, and possibly even some nicer places to eat dinner. Since most tour operators are flexible about cancellations I may even over-book us so that it will be easier to pick what to do based on current volcanic activity. (The helicopter people, for example, have already said they will let us cancel with full refund if there is no eruption when the time comes to fly there.)

            Because the trip to Askja is long and requires a 4WD I wouldn’t try to drive it myself. There is at least one operator who does that trip. I don’t know how much time we would get to spend on the ground at Askja. … I just looked to see if I can get a flight from Akureyri to Myvatn and I can’t. But it is a great idea to think about using air travel to make the trip shorter. I know helicopters are more expensive, but it makes a lot of sense for me to look into taking one from Akureyri or Myvatn to get to Askja. We’d be able to land and walk around. Since I’d only go to Askja if there is no eruption for us to fly over, we would be replacing one helicopter trip with another rather than adding another large expense. I hope my travel agent will be able to help me work out the details, verify the credentials of the tour guides, etc.

            I have now booked our lodgings and will book the flight from the U.S. in the next few minutes. Then I will look into the availability of autos for hire. If they aren’t in short supply yet I’ll wait for the travel agent to help book them — I’m sure the agent will get commission and probably a better rate.

            And for those of you who worry because I’m saying all of this online on a public forum, we will, of course, have a house sitter.

        • “statistically speaking,” you should realize that volcanoes don’t do statistics.

          GL Edit: Sorry, that’s a bit trite.
          What I mean is that we humans can use statistics to summarize and examine the past behavior of volcanoes, but doing so is really no indicator what so ever of future performance. Volcanoes live in a chaotic world where every action is dependent on a vast number of variables that it is pretty much impossible to measure accurately, much less to do so in real time. As such, they tend to do what the prevailing conditions dictate rather than what a statistical analysis states that they should be doing.

          • GL, I get it. That’s why I’d said “(Of course I know this is purely hypothetical and not real-world. Yet someone might enjoy trying to answer it 🙂 )”

            I’m saying this “out loud” to help shake it into y’alls noggins that I am not always as outlandishly ignorant as I sometimes (often?) appear to be.

          • No biggie. Due to circumstances beyond my control I have been quite focused on probability. (I’ve mentioned cumulative probability here recently and how the odds of something happening can become very remote very quickly).

            Besides, our last two articles have had something to do with probability, and it is sort of making me want to do a third article, though coupling it into volcanoes. The problem is that statistical monkey that I have been dealing with of late is one monstrous time sink. The first two days of this week have been 400 km round trips… with a lengthy onsite time in the middle of each. Usually, I like to sleep in on the following day for trips like that in order to give my brain a chance to catch up. Today I was gonna try, but got tangled up in juggling shipping documents instead. Then a high priority get it done yesterday call comes in and the point of contact can’t be available until tomorrow. I find this out halfway to the site. So, I stopped and grabbed a burger and wound up cursing a Red Corvette instead. Seriously, I can understand being polite and stopping to let another car turn, but to do so from the posted limit to a dead stop with a lot of traffic behind you? I now believe that corvettes are specifically designed so that older men can pick up teenage girls. “pedomobiles.” That’s how highly I thought of that idiot’s driving. Had I been in anything larger than that Van, I would have driven over him he stopped so abruptly. (however, if I had that sort of mass I would have given myself more stopping room, you drive for the capabilities of the vehicle you are in.)

  17. I am enjoying watching Leslie plan her family holiday, not without some envy! I can add nothing really except take the advice of local people and some warm clothing .Also some activity books for the children to keep them occupied during long journeys. What may seem interesting through adult eyes can be tedious for a child when long journeys seem never ending!
    I too have booked a short holiday this week, bought for me by my son for my birthday. We are going at the end of April when hopefully the weather will be warming up.
    It’s posh camping in a Yurt in the ground of a stately home in Shropshire. The link below will take you there.
    It is the first holiday with Meg & Poppy and that will be adventurous! There are small lakes and field and woodlands to run in . Taking the dogs needs nearly as much stuff as taking the kids!
    I was really impressed with the toilet facilities 😀
    No volcanoes. No mountains. But I am looking forward to exploring the English countryside of Shropshire in the Spring. Birds singing and an arboretum where I can hug trees to my hearts content and my long suffering husband can just chill 🙂


    • And again, the large dog proves his worth. Another estimator came by to quote an estimate on my roof. Large dog was not happy with an interloper at the door. By the time I got to the door, he had back up a good ten feet from the door, not wishing to be very close should “the creature” make it out the door. (The roof thing is a pre-emptive decision on my part since I live in a hurricane prone area.)

      Now, I realize that Asphalt shingles are essentially obsolete… but kevlar based shingles? That should be pretty handy if someone in a helicopter decides to unload a clip at my house…

      • Because we don’t have hurricanes and tornadoes ( Well not USA style ones) I never thought about why our roofs have tiles or slate and not lighter wood or other material as in the USA and other countries. Also different, the thought of our local police helicopter shooting at it. As we , in the UK, don’t carry guns, unless one is a farmer shooting pests or on the way to a game shoot (Hunting, well sort of!) , it never enters my head that I or my property could be shot at.
        Now I am worried as our bed is right under the large Velux window that takes up most of the area on that side of the roof.
        Should I get bullet proof pyjamas? 😀 😀
        Would Kevlar tiles deflect wind? I can see them restricting damage by large hail stones that often accompany extreme storm cells.

        • It was mainly a logical exercise based on what kevlar is usually known to be used for. Asphalt shingles are usually enough to handle hail stones… with Kevlar, I can only think of armed helicopters or really small meteorites. (with a larger one you won’t really care if the roof survived.)

    • “where I can hug trees to my hearts content ”

      Funny that. I was asked recently by a cousin about who to contact to cut down a stand of pines. One of my aunts had them planted years ago just to tweak a neighbor who wanted to use the land as pasture since my grand dad had passed away and was not longer using it. (not a good history with the neighbor BTW). She has since passed away and the land is under joint ownership among us grandkids. My advice was to bid out the timber and to use the proceeds for any tax liability that we had.

      Though I detest that state, I still technically own property there and will use it as refuge when the economy fully collapses. The politicians will be lucky if they can get out of the State Capital alive. With about three large river systems between there and the Capital, I’m not that worried about refugees headed that way. If they go by foot and don’t stick to the roads, they will never make it. Too many swamps and bottom areas to get lost in. The snakes are something fierce.

    • And I am dreaming about going back to France in the fall, and if I fly Icelandic Air, they will let me stay in Iceland for a week on the way there! I won’t be taking a tent, so if lodgings are booked that far ahead, I had better do some looking soon.

    • No volcanoes, No mountains – ?!

      The Wrekin is (kind of!!) both, isn’t it? And the Church Stretton valley has some interesting volcanic stuff, too, I think. Lovely county. EM Forster said that “if Shropshire had the vote, it’d vote Liberal.”

      • I shall have to read up on the Geology of the area. 🙂 I have never been in that part of the UK before 🙂

        • Well, I hope you have a great trip.

          I was a boy in the area and loved to go up to the Long Mynd. I’d ask my parents why it had that name but they couldn’t tell me, but now, with a smattering of Icelandic, I think I know. And it’s a most fitting name, too… (Some more detective work for you 🙂 )

  18. I am here on this site since the beginning of this episode. My relationship with Google Translate is known … I hate it lolllllll However, I read you every day and I learned. At least I try to understand even if English is not a first language. I just hope what I write may be understandable.

    When I watch this episode of distance, with detachment and, above all, an amateur that I am, I can imaged all in my head.

    The Earth’s core gets excited and agitated, causing magma rise everywhere on the planet. In Iceland, the shortest and fastest route is around the Bardabunga. Good pressure causes the creation of a dike because the soil is weakened at that location. The magma following his path and resulted in the outpouring that we know.

    A light quiet (or imbalance in the kernel) causes a slowing of the arrival of magma. The pressure drop across the dike causes the subsidence thereof.

    The magma takes its course but has not his usual way. He seeks one or more other but the ground is too frozen. Meanwhile, the boilers are filled again at the discretion of adrenaline (humor) from the core.

    All combat commotion resulting in unstable and fragile area … especially the caldera itself collapses … the house of mr. magma becomes uninhabitable. He will have no other choice than to go elsewhere.

    Does it come out through the main door or build there a fire exit to replace the one that is closed?

    The instability of our core is not ready to calm down. Even our magnetic field is affected. Magma will continue to walk for a long time and it is likely that Iceland will be an efficient point out … that’s a teenager island geologically speaking; therefore, still malleable.

    Does the Bardabunga erupt? The logical step would be yes.

    One of the first thing I wrote on this site was my vision of all this: Iceland will redraw and we witness his draft. I have not been wrong;-) … And it’s not over

    • Not bad, but it’s not the core contributing magma… at least not directly. Heat, yes, but not magma.

      Some papers have pointed to oddities in the He signature of Bardabunga magma being evidence for not being a deep seated plume, yet the hotspot does show up quite well in seismic tomography. My interpretation for this disparity in evidence is that the Icelandic hotspot is from a mid-mantle origin. It could be an ancient oceanic plate shard undergoing melt at depth (hello ringwoodite) or some artifact of the plume that was responsible for the Siberian Traps… after circumnavigating the polar region and tracking through Greenland. (Who knows, It’s just one of the ideas I’ve seen wandering through the Cafe.)

      One thing that is quite disturbing, is that rifting phases in Iceland tend to be periodic in nature, and that we are entering that window of time when Iceland does it’s thing along the rifts. A paper not too long ago noted that the Icelandic hotspot was an incipient feature. That could be somewhat ominous if you take words at their meaning. “incipient” means “Beginning to exist or appear.”

      • I looked up “Core-mantle boundary” on Wikipedia and found this nice graphic which shows that the Earth’s core is more than 5000 km deep! I think that magma is coming from the upper mantle, which is only 35 km deep (and goes down from there).

      • And elsewhere in Wikipedia

        “One group of researchers was able to estimate that between 5 and 10% of the upper mantle is composed of recycled crustal material. Kokfelt et al. completed an isotopic examination of the mantle plume under Iceland and found that erupted mantle lavas incorporated lower crustal components, confirming crustal recycling at the local level.”

        Remember that the area where Iceland is at used to be part of the subduction zone feeding the Caledonian orogeny

        My pet idea is that Iceland’s crust is so thick because of a section of continental crust getting placed on top of a section of oceanic crust. We know that slivers of the crust of Greenland have been sheared off and set adrift on their own, one such contender being the Jan Mayen microcontinent. It’s currently sutured to the Eurasian plate. Geochemical testing would confirm or disprove that, but I have no references that state either way.

  19. The birth of a new island in Hunga Tonga, visualized at “http://www.geo-airbusds.com/en/6322-eruption-of-a-volcano-in-the-tonga-archipelago-pleiades-captures-the-birth-of-a-new-island”

  20. Hi all, here’s a new timelapse from Bardarbunga covering periods from the 25th to 28th of January.(See left corner)
    A silent version can be found here http://youtu.be/RmkKHBbUeeo (in case the video would be blocked)

    Music Gymnopedie #1 by Eric Satie
    performed by John Hackett and Steve Hackett

    I addedd some background windnoise though.

    Around 2:55 a particular bright object passess. Due to it’s brightness and size I assume it can only be Venus?

  21. I am not a geologist but I have a question for the dragons. I know that Iceland sits on a huge mantle plume and in the last 24million years it has grown to its present size and shape. I would like to ask if the Outer Hebrides were part of this plume which broke away millions of years ago.. I know that a super volcano existed (i think on Skye) but would love to know could this same giant plume be responsible for the making of this giant extinct super volcano.

    • Sort of. Sort of not.

      The Icelandic Hotspot (I avoid the use of the term “plume” since there are easily excitable people out there who will fight over the use of the term) is in all liklihood, the central player in the North Atlantic Large Igneous Province. In that respect, it’s a partial suspect. The big kink in that idea is that the Caledonian orogeny probably had a greater influence in the formation of the Hebrides. At the time, the Paleozoic era microcontinent of Avalonia existed in this region, having been scraped together from island arc volcanoes and subduction processes. When the Atlantic rifting episode came along, pieces of Avalonia were distributed on the eastern and western sides of the rift. Parts of the Greenland crust were sheared off and the whole region became a collection of disparate blocks that became the area as we know it today. Jan Mayen island is a relatively new feature, springing up from volcanism on the northern edge/corner of the Jan Mayen microcontinent. When the Aegir ridge shut down, the Jan Mayen microcontinent became a defacto part of the Eurasian plate. (effectively welded to it). The full extent of the North Atlantic Large Igneous province probably stops at the Faroe Island platform, and the Icelandic hotspot is just an unwitting suspect being blamed for the crimes that occurred before it arrived… sort of like that “problem child” that the attendance officer at my high school had been trying to nab for an entire year. She knew he was up to no good but could never catch him. One year, as part of the Senior class shenanigans, he happened to wander into the rest room at about the time that a bundle of 500 firecrackers were set to go off. (fused with a smoldering cigarette). She caught him, though it wasn’t his prank.

    • Just a correction, Ian: I think you mean the INNER Hebrides, most of which are Tertiary basalt volcanics and intrusives (Skye, Mull, Eigg, Rhum etc). The Outer Hebrides, if I remember my geology from long ago, are of ancient metamorphic rock far older than the NALIP

    • I should since I set it up. Improvised fusing devices were my hobby back then. I even had Archer™ kits that could set off fireworks based on lighting or sound. Probably the stupidest “experiment” that I did was setting off milk jugs with bottle rockets. With just under a half an ounce of gasoline, the thing makes an impressive little “Whomp!” when it goes off. Then you have to scurry around and put out the grass. In todays society, kids get arrested for less.

      I characterize it as stupid from the knowledge that I have accumulated over the years, not for any mishap. My only real mishap from back then was when I accidentally branded myself.

      I never fiddled around with more advanced incendiary items. Just listening to my dad relating the hazards of rolling out mercury fulminate shied me away from stuff of that nature. If just one grain of the composition dries faster than the rest, the whole batch can go off as you are loading your primers. Later reading shows that TATP is likely prone to a similar effect. This is probably why so many terrorist bomb makers never make it to an old age. Even if you don’t kill yourself mixing the stuff, dealing with it’s variable stability can be quite a gamble unto itself.

  22. Pingback: Ruminarian IX? Musings on Hekla. | VolcanoCafé

  23. I’m curious to see if the possible under-glacier eruption has effected the Level of Jökulsá á Fjöllum, but can’t access the hydrology data. Has there been a rise?

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