Krakatoa skies: when the Sun turned blue

Just after 4pm, the phones started ringing at the Royal Observatory on Blackford Hill. Caller after caller reported seeing the sun. The date was September 27, 1950, and the place was Edinburgh, Scotland. Seeing the sun in Scotland can be a bit of a rarity, but even the Scots knew that the sun should not look like this. Over a quarter of an hour, the sun had turned bright blue, while the sky took on a bronze colour. The Scotsman reported “All over Edinburgh, on the streets and in suburban districts, people stopped to gaze at the sapphire sphere shining in a greyish-white sky.” The Astronomer Royal requested an airplane to investigate. Above 10 kilometer altitude, the sun was its usual yellow. Below that, it was distinctly blue. In between, a layer of smoke seemed present. The phenomenon lasted until 6:30pm when the sun regained its normal hue. But later that evening, when the moon rose, it too was blue. A young Patrick Moore wrote “The moon was in a slightly misty sky and had a kind of lovely blue colour comparable to the electric glow discharge. I never saw something similar before. Indeed, nothing like it had been seen since the blue sun of August 18, 1821 had appeared in the skies of southern England.

Blue-green sun over Boulder, Colorado. Gedzelman and Vollmer 2009

The cause of the 1950 discolouration was across the Atlantic, in Alberta, Canada. A forest fire had been burning there since June but it had largely been left alone: fire fighters were told to only tackle fires within 10 miles of a town. By September, the deflagration had become huge and late September, the sun over eastern Canada went out, hidden behind the dense smoke. The Chinchaga firestorm had grown into the biggest wildfire on record in North America (it still is). The smoke particles blew over the Atlantic, and when the haze reached the UK, the sun turned blue.

Whilst blue suns are very rare, red suns are more common. In October 2017, as the UK was hit by a post-tropical hurricane, the sky went yellow and the sun red. It was quite an amazing sight. It was also amazing to see the students just looking down at their phones, rather than up at the sky. Perhaps in their on-line world, the colour of the sun is of no particular interest. We can teach our students to think, but it has become harder to teach them to see. The red sun was caused by a combination of dust from the Sahara and smoke from forest fires in Portugal, caught by the hurricane.

Red suns amidst hazy skies had also been a feature of the dry fogs of the Laki eruption, in 1783. But the most famous instant of strangely coloured suns happened in 1883, when the eruption of Krakatoa painted the sky world-wide in unworldly colours. Let’s have a look.

Krakatoa

Eruption of the volcano on Krakatoa, August 1883. Photograph: Dea Picture Library/De Agostini

The eruption had been a terrible one. Captain Watson of the ship Charles Ball was in the vicinity, and he wrote a vivid account of the events.

The night was a fearful one: the blinding fall of sand and stones, the intense blackness above and around us, broken only by the incessant glare of varied kinds of lightning, and the continued explosive roars of Krakatoa made our situation a truly awful one.

“At eleven P.M., having stood off from the Java shore, with the wind strong from the S. W., the island, being W. N. W. distant eleven miles, became visible. Chains of fire appeared to ascend and descend between it and the sky, while on the S. W. end there seemed to be a continued roll of balls of white fire. The wind, though strong, was hot and choking, sulphurous, with a smell as of burning cinders, some of the pieces falling on us being like iron cinders. The lead came up from the bottom at thirty fathoms quite warm.

“At 11.15 [a.m] there was a fearful explosion in the direction of Krakatoa, then over thirty miles distant. We saw a wave rush right on to the Button island, apparently sweeping entirely over the southern part, and rising half-way up the north and east sides, fifty or sixty feet, and then continuing on to the Java shore. This was evidently a wave of translation, and not of progression, for it was not felt at the ship. This we saw repeated twice, but the helmsman said he saw it once before we looked. At the same time the sky rapidly covered in; the wind came out strong from S. W. to S., and by 11.30 A. M. we were enclosed in a darkness that might almost be felt; and then commenced a downpour of mud, sand, and I know not what, the ship going N. E. by N. seven knots per hour under three lower topsails. We set the side lights, placed two men on the lookout forward, the mate and second mate on either quarter, and one man washing the mud from the binnacle glass. We had seen two vessels to the N. and N. W. of us before the sky closed in, which added not a little to the anxiety of our position.

At noon the darkness was so intense that we had to grope our way about the decks, and although speaking to each other on the poop, yet we could not see each other. This horrible state and downpour of mud and debris continued until 1.30 P.M., the roaring and lightning from the volcano being something fearful. By two P.M. we could see some of the yards aloft, and the fall of mud ceased; by five P.M. the horizon showed out to the northward and eastward, and we saw West Island bearing E. by N., just visible. Up to midnight the sky hung dark and heavy, a little sand falling at times, and the roaring of the volcano very distinct, although we were fully seventy-five miles from Krakatoa.

(https://www.theatlantic.com/magazine/archive/1884/09/the-volcanic-eruption-of-krakatoa/376174/)

Soon dust was falling over much of the Indian Ocean. It was the 27th of August 1883, and Indonesia had just lost one of its islands. The explosion had been horrendous, and the death toll terrible. And Krakatoa was only a VEI 6! This was the first significant volcanic eruption, and the first major catastrophe, in the time of instant communication. The Dutch Java Bode published the stories on the same day of the eruption. English newspapers soon followed. The complete destruction of the town of Anjer was especially newsworthy. Even with the new telegraph links, the confirmed information could still be limited. “”All gone. Plenty lives lost”, read the content of one such message, leaving the journalists with some creative writing to be done. They rose to the challenge.

San Jose Weekly Mercury, 6 Sept 1883. The 16 active, towering new volcanoes formed by creative writing.

The world in colour

But now the eruption was over, and the experience of a life time began, one that covered the world in colour. Already before the main eruption, there had been an effect in the skies. Watson had noticed peculiar red sunsets while in the South Atlantic several weeks before the main eruption, perhaps related to the earlier activity. And a week before the main eruption, as Krakatoa’s activity was getting stronger, he wrote

about seven P.M. on the 22d of August, in latitude 15° 30′ S. and longitude 105° E., the sea suddenly assumed a milky-white appearance, beginning to the eastward, but soon spreading all around, and lasting until about eight P.M. There were some cumulus clouds in the sky, but many stars were shining, and from E. to N. N. E. a strong white haze, or silvery glare; this occurred again between nine and ten P.M., but disappeared when the moon rose. The clouds appeared to be edged with a pinkish-colored light; the sky also seeming to have extra light in it, as when the Aurora is showing faintly.

But the effects became incomparably stronger after the main explosion. A passenger on a sea liner wrote

The sky was continually of a green colour for some days […] the sunrises and sunsets were indescribably beautiful, tinged with every shade of green not simply at the place of rising and setting, but thrown back on the rolling clouds all around the horizon. […] I thought it was nothing more than fine particles of mineral substances which had been forced up into the clouds by the volcano, and carried along above the region of the earth’s influence. The phenomena lasted until we had entered the Red Sea, at a distance of between 3,000 and 4,000 miles from Anjer.”

And two weeks after the eruption, on September 9, 1883, north of Borneo, Watson reported that the sun rose perfectly green, and that the moon and the stars gave a green light as well. The strangeness had begun.

Suns of colour

The coloured suns had begun during the early sputterings of Krakatoa, long before the major eruption. Within days after the initial explosions on 20th May, a report from the ship Elisabeth, near Krakatoa, reads “After this followed a rain of a very fine grey-yellowish dust which penetrated everything, and which continued to fall until the night between the 21st and 22nd of May. On the morning of the 21st the light was that which prevails during an eclipse of the sun; the sky presented the aspect of a large dome of very thin opal glass, to the vault of which the sun seemed suspended as a pale blue globe.A nearby ship reportedThe sun looked like dull silver.

After the final, destructive Krakatoa explosions, the reports of strangely coloured suns multiplied, and began to spread around the tropics. The first report was already on Aug 27, from a small region in Sri Lanka, where the sun became green. Initially, coppery, silvery, and even a leaden sun were reported. This was closer to Krakatoa and only in the first days, apart from one report from Tokyo on August 30, apparently at the receiving end of a narrow high-altitude air stream. Once the densest dust clouds had dissipated, the other colours began to appear. A blue sun was seen in the northern part of South America, from Panama to Parimaribo, on Sept 2. In Honolulu, on Sept 5, the sun went green. In Sri Lanka, a green sun was seen on Sept 9 and again on Sept 22. The Red Sea had a green sunrise on Sept 10 and a blue sunset on Sept 24. A green sun was seen at the coast of China on Sept 10. Sept 15 saw a green sun over the Atlantic. A blue sun hung over Trinidad on September 2nd, and over Barbados on September 15. The last report of a green sun was on September 28. (There was a final, perhaps unrelated report on January 24, 1884, of a green sun at Cracow.) A coppery sun was seen near the Equator, including on August 31 off the west coast of Africa; at Fanning Island, on September 4, and over the Atlantic on September 7.

There are some patterns that can be recognized from the observations. The silvery or pale sun was seen when the sun was highest in the sky, and where the volcanic dust was densest. A coppery sun appeared at larger distances, but mainly along the equator, suggesting the dust was still dense. Blue and green suns were seen furthest from Krakatoa, through thinner, older dust cloud. By that time the clouds had become difficult to see: the blue suns were most often seen without recognized clouds. Many observers expressly state that there was no cloud. However, the volcanic cloud was there, as shown by the fact that the sun would be fairly dim at the same time: the blueness was due to the loss of yellow and red light. Typically the sun would be green closest to the horizon, changing to blue 10 to 20 degrees above the horizon. Usually the sky was not red, but white, grey, or blue before a white or blue rising sun, or after a setting sun of white or blue appearance.

This suggests that the densest and coarsest dust caused silvery suns, and blue and green suns came from thinner layers with smaller dust particles. These moved around the world from east to west, taking 13 days to complete a circuit. The zone over which it was seen gradually widened over this time.

The coloured sun was not unique to Krakatoa. For example, during an eruption of Cotopaxi in 1880, when the sun was seen through the eruption cloud, from a distance of 100 kilometer away, the observers stated: “We saw a green sun, and such a green as we have never, either before or since, seen in the heavens.

Painting the skies

It was not only the sun that was painted in colour. The sky itself seemed on fire. In combination with the coloured suns, one person wrote how the wonder continued into the evening: “After sunset, the rays showed another range of colours: yellow, orange, and finally deep red.” It had started as a haze, immediately following the falls of dust and causing a red glare in the sky. Later, the skies looked white. This was seen over the Indian ocean, within a day of two of the main eruption. The dawn in Mauritius was crimson. On St Helena, on August 30 a red light was seen in the south. South of the equator the skies were mainly hazy and blue suns were rare or absent. A few days later, the skies went white, and later yellow. The spectacular twilight colours came after the densest dust had settled. The glows reached Cape Town on September 20, indicating that the dust band were gradually widening. From October 1, the brilliant colours expanded north, reaching places as diverse as Shanghai and Florida, mirroring those in Australia and New Zealand.

By 10 October, the lurid sunsets reached the UK, faint at first but growing in intensity during the month. It waxed and waned as the volcanic dust moved around the globe, at times reaching as far as Iceland. On November 9 the glows became spectacular, and they remained so during December. In the Ribble valley,  Hopkins wrote; “the glow is intense; that is what strikes everyone; it has prolonged the daylight, and optically changed the season; it bathes the whole sky, it is mistaken for the reflection of a great fire.” Later he wrote a report to Nature:

Above the green in turn appeared a red glow, broader and burlier in make; it was softly brindled, and in the ribs or bars the colour was rosier, in the channels where the blue of the sky shone through it was a mallow colour. Above this was a vague lilac. The red was first noticed 45º above the horizon, and spokes or beams could be seen in it, compared by one beholder to a man’s open hand. By 4.45 the red had driven out the green, and, fusing with the remains of the orange, reached the horizon. By that time the east, which had a rose tinge, became of a duller red, compared to sand; according to my observation, the ground of the sky in the east was green or else tawny, and the crimson only in the clouds. A great sheet of heavy dark cloud, with a reefed or puckered make, drew off the west in the course of the pageant: the edge of this and the smaller pellets of cloud that filed across the bright field of the sundown caught a livid green. At 5 the red in the west was fainter, at 5.20 it became notably rosier and livelier; but it was never of a pure rose. A faint dusky blush was left as late as 5.30, or later. While these changes were going on in the sky, the landscape of Ribblesdale glowed with a frowning brown. (from G. M. Hopkins, “The Remarkable Sunsets”, Nature 29 (3 January 1884), pp. 222-23)

Tennyson expressed it in poetry, perhaps not entirely successful

Had the fierce ashes of some fiery peak
Been hurl’d so high they ranged about the globe?
For day by day, thro’ many a blood-red eve
The wrathful sunset glared

Sadly, even though photography existed, that was only in black and white, leaving the painters and writers with a monopoly on colour. The main painter giving it a go was William Ascroft who watched from the banks of the Thames. The reds and yellows in his paintings give a good indication of the spectacle.

Norway was also impacted. Edvard Munch wrote about the sunset

it was as if a flaming sword of blood slashed open the vault of heaven,” he recalled; “the atmosphere turned to blood – with glaring tongues of fire – the hills became deep blue – the fjord shaded into cold blue – among the yellow and red colours – that garish blood-red – on the road – and the railing – my companions’ faces became yellow-white – I felt something like a great scream – and truly I heard a great scream.”  And that is what he painted, complete with the fiery red background.

Other reports are plenty:

Very brilliant twilights, morning and evening. Sky became red about 1 hour before sunrise, and gradually faded. Just after sunset the sky began to grow red and continued increasing in brilliancy for about 1 hour. On 24th Oct like a great fire in south.

In the morning a luminous silvery twilight; as the sun came up the light rose nearer to the zenith changing to a reddish-pink and forming a crescent, beneath which was a pale green colour of an apparent diameter of 60°. As sun rose the colour changed to yellowish-red.

In Austria, Baader remarked on a morning twilight at Marburg, in Steiermark: “When I woke on December 1 towards 6 o’clock, I observed at once, through my window towards the west, an intense red; mountain and valley were covered with a marvellous glow. The vineyards towards north and east, the Matzelgebirge, south and north-west, the snow-covered hills of Bacheon and Posruck, all was, including the whole sky, a sea of fire, the fog in the valleys like molten metal. About 6.45, on going out I saw, to my great astonishment, in the E.N.E, an arc spanning the sky, which was yellowish and in parts pure blue, up to about 20 degrees. The boundary of the coloured space was sharply marked off from the blue firmament, and moved with great speed towards W.S.W., although there was hardly a light current of air. In a short time nearly the whole sky up to the zenith was free from the phenomenon—only in the far west a sharply defined arc appeared for a short time.

Although the glows continued, from January the brightness declined, and in the UK by April only faint traces remained.

In addition to the coloured skies, the general haze which had started immediately after the explosions, remained present. It had a strong effect: the sun was surrounded by a glow, a corona extending some 30 degrees. In January 1884, a UK observer wrote about this “It has been visible on every clear day for more than two months, and has been quite independent of wind and weather.” The haze continued for longer than the twilight colours. The final report was in Oct 1886, when it briefly re-appeared after a summer absence. After this the skies had completely cleared.. The corona is named Bishop’s ring, after Rev. Bishop in Honolulu who had first described it, on 5 Sept 1883. It seemed unrelated to the colours of the sky: the corona had always the same whitish appearance. But it was not seen from the big cities, London and Berlin, and this was attributed to the smoke which hung over these cities.

The spectacular sunsets were due to volcanic dust clouds at very high altitude. Different observers found different heights, with 15-20 kilometers commonly derived. But the height appears to have been decreasing from November 1883, at a rate of 1500-3000 meters per month.

Dry fogs and sulphate hazes of course had happened before. Laki, in 1783, had caused white skies and powerless sunshine for a full summer. The haze had extended from the sea-level to an elevation higher than the tops of the Alps. But the amazing colours were missing. The layer may have been too low in altitude: if it had been over 10 kilometers, the brilliant Krakatoa sunsets may have been expected.

The Krakatoa haze showed up in other ways: the atmosphere remained more opaque than normal for over a year. In October 1884 and March 30th, 1885, there were total eclipses of the Moon. Several observers noted that the eclipsed moon was unusually dark, darker than it had ever been seen. ” The usual copper tint of the eclipsed moon was not perceived except towards the close of the eclipse, and then it was only very slight.

In the winter of 1885 the twilight colours re-appeared, albeit much fainter than before. A second re-appearance was in the following winter. After that, the world had returned to its pre-Krakatoa state – minus one island.

Tropical jet stream

The coloured suns and related phenomena revealed something that had been unknown before: a high level tropical jet which catapults air around the globe from east to west. The effects allowed the speed of this jet to be measured. For instance in Sri Lanka (Ceylon), the coloured sun was first seen on August 27. After that, it appeared on September 9 to 12, and 22 to 24. The intervals from August 27 to September 9 and from September to 22 are both thirteen days. Krakatoa beat Phileas Fogg by 67 days, at an average speed of around 130 km/h. This period of 13 days was seen in many places in the tropics during September. During the first circuit, the cloud expanded to the region between 22 degrees north and 33 degrees south, or about 28 degrees from the latitude of Krakatoa in both directions. The spread away from the equator happened at 10 km/h. During the second transit, the cloud added about 10 degrees latitude, at 3 km/h.

There is an easterly tropical jet crossing the Indian Ocean, at 10-15 kilometer altitude, running at the right speed. It is driven in part by the Indian monsoon, and reaches speeds of 140 km/h. It is seasonal, and is strong from June to September. The Krakatoa eruption occurred during its peak, and this contributed to the spread of the coloured suns. It would have been a different story had Krakatoa erupted in November.

1831

Krakatoa is not unique in its colouring of the skies. A mini-Krakatoa appears to have happened half a century earlier. In September 1831, brilliant orange and red sunsets were seen throughout southern Europe, and the sun had the dead brilliancy of the moon. It had started earlier. The first reports were of haze and blue sun on August 3, from the coast of Africa. A few days later it reached Odessa and southern France here the sun went green and azure. The US was impacted from August 13, and New York had its blue sun on August 15; the Bermudas had had a preview on August 11. The light of the sun was so much diminished that it was possible to observe its disc all day with the unprotected eye. On the coast of Africa the sun became visible only after passing an altitude of 15° or 20°. The sky was never dark at night, and at midnight, even in August, small print could be read in Siberia, Berlin, and Genoa. The time fits with the appearance of Graham Island, off Sicily, on August 1, but it seems surprising that this eruption was major enough to impact New York.

Smiles in the sky

It is always worth looking up. There is no telling what you might see! That blue sun in a yellow sky may reflect a distant volcano.

Albert, October 2017

Most of the excerpts are taken from: the Royal Society (Great Britain) report of the Krakatoa Committee: “The eruption of Krakatoa, and subsequent phenomena.”, available from Gutenberg.

244 thoughts on “Krakatoa skies: when the Sun turned blue

  1. What a splendid article Albert! Thank you. I took great delight in reading some of it out to my son who has a passing interest in volcanoes (hopefully, one day, he’ll be logged on here, too!)

  2. A really good read, thanks Alb.ert. Especially after the Ophelia skies here in the UK some days ago.

    The venting is currently really picking up on the summit of Agung over the last hour. Having watched it, I suspect BillG is right . The left side of the plume consistently has a dirty and slightly yellow/brown look to it.

    • The dirty grey smog at the foot of the mountain is now easily seen and appears to be spreading outwards from the mountain…on an otherwise sunny day. I’m going to stick my neck out again. I think there’s some form of sputtering low level ash emitting activity on the summit.

      • Local time 9.48.20… That definitely looked like some kind of small explosion on the summit on the cam linked above.
        But I need sleep.
        I wonder what I’ll see there when I wake again.

          • It now actually looks a very great deal calmer.
            It’s hard to use words like “spectacular” in the context of volcanoes when they’re NOT throwing thousands of tonnes of geology around the place, but it occurred to me that if it were anything BUT a large volcano, that descriptor would have been justifiable for what I was seeing at around 9.50 am local time.
            And for the record… I don’t sit here staring at the screen all day. I have it running whilst I’m doing other things. It’s so much more interesting than a windows screen saver.

      • The grey smog is probably just that – grey smog. It will be the smoke from the many fires. The interesting bit is at the top.

  3. Hello…..

    First of all, very nice, well written article. Your site always had top-notch contents on it, you’re right on the spot, making things scientifically enriching without drowning you in technical stuff. Both informative AND interesting, elusive stuff nowadays.

    I’m lurking here from several years on, started when Etna was throwing those marvelous paroxysms in the 2012-ishs… Then the grand show at Kelud rekindled my love of Indonesian volcanoes. That was an amazing feat of VSI professionalism, turning a volcano which has been an historical epic killer into a well-managed volcanologist’s dream come true…. A gigantic explosion, ash 26 km up in the skies, basically one-hour-worth of Pinatubo without anyone dead and only marginal damage. I’m out of words to express my awe at their work.

    Sorry for the digression, back to slightly less of-topic…

    A few days ago, I was persuaded that Agung had pretty much done it all, since the decline of seismic activity told me (I’m no specialist whatsoever) that nothing more was going on inside the mountain. I had just overlooked that, effectively, lack of seismic activity can be caused by lack of movement…. or lack of stuff to break, as it’s already all pushed to the side by the risen magma.

    Then those really strange continuous signals started showing up. Timing is not regular, and unlike in Island, there are no big storms to provide false readings, so…. unless there’s a deranged guy running around the seismic station with a bulldozer for hours (someone would have noticed him I suppose), those quakes mean something, and Agung is clearly talking to us, albeit in a language we can’t understand.

    Are those trace magma pulses making their way into an already cleared path? Is it the Hindu god of the mountain shouting at us in Sanskrit through rock to stop spying on him? Well, the more time passes the more the mystery thickens.

    I have a feeling, that contrary to what I was deeply convinced a few days earlier, we’re in a status very similar to Mt St Helens in April 1980…. As Dr Johnston (who was to perish in it) said, we’re dealing with a lit stick of dynamite, where no one knows how long the fuse is.

    VSI once again did the right thing keeping the alarm status up, should they have lowered it and allowed the refugees to go back home, Murphy’s law would have struck in an instant, and the whole thing would have gone kablam.

    Reminds me of something… When Pinatubo was preparing for the big one, it was shimmying and shaking all over the place, until a few days before going pyrotechnic. At this time, everything became dead quiet, to the point PhiVolcs (another gifted team of lifesavers) were pressured to let people back in. They didn’t. It went bang. Had they cancelled evacuation, there would have been hundred thousands people burnt alive by pyroclastic flows.

    Sorry for my lengthy post and my broken English, you know the old cliché, French people are loudmouths with no grasp on any foreign language whatsoever. Ditto.

    • Welcome!

      It always amuses me when people apologise for their English, they almost all have a better grasp of the language than most native speakers!

      Let me say this, had you not mentioned you were French, I would have had no idea 😊

        • Don’t try.
          Just try to express your ideas and observations as clearly as you can. You will probably find people here who will help you if you find a concept difficult to explain.

    • On Agung:

      1. The authorities are keeping it at alert level 4 for at least another week. They know their stuff and have good reasons for their calls.

      2. Seismicity is a good bit lower than it was last week – but it’s still elevated way above background levels.

      3. I think the lower level of seismicity has allowed them to dial up the sensitivity on the drum plot. As a result, there’s now a clear diurnal pattern; a background of human noise that starts around 7am and tails off around 8pm. Those may be the signals you’re seeing.

      4. Pinatubo never went quiet; activity went up and down as the event progressed – but there was always a clear overall upward trend. The only thing that really went down closer to the eruption was SO2 flux IIRC – and this was interpreted, correctly, as a *bad* sign; the system had sealed up and was pressurizing.

      • So like I said… One “convincer “would be a build up of noise during a period of calm weather in the middle of the night, when human activity was at a low level.

        I remember one of the USGS guys at Pinatubo talking about the pressure they were placed under. He mentioned how hard it was to make objective decisions based on data when everyone from local communities, to the US military and the Phillipines govt , and he also mentioned the old adage about a frog put in hot water would jump out, but a frog in cold water would stay there even if the water were gradually heated to the point where it died.

        And thus he was able to deal with the pressure because he was brought to the conclusion that they should take a snapshot of current conditions set against the pre-crisis data as far as it was known, rather than comparing data to the last few days.
        And compared to base levels, all the data pointed keeping alert levels high.

      • Speaking of which, are there any recent SO2 readings for Agung?

        (BTW Albert; great posting as always, but as a native of Edinburgh, that was an unjustified slur on the local weather Edinburgh sees quite a lot of sunshine actually Now Glasgow, that’s a different matter…..)

        • As a native Dundonian, we scoff at your claims of sunny weather!

          Feel free to visit Scotland’s Sun City anytime 😉

          “Dundee
          Dundee is the sunniest city in Scotland. On the longest day of the year there is no complete darkness over the northern isles of Scotland. Lerwick, Shetland, has about four hours more daylight at midsummer than London, although this is reversed in midwinter.
          Climate of Scotland – Wikipedia”

        • I live in Manchester. Even on sunny days there is little sun because of the plethora of aircraft contrails. It is notable that whenever flights don’t fly because of some reason, the sky clears. I know Edinburgh (nor been to Dundee) and know that the east of Scotland is sunnier than the west. But this was too good a chance to miss – Scots calling the Observatory to report seeing the sun!

    • You did fine. A nice thoughtful comment that fully illustrates the hazard. As for Murphys law, it is actually a manifestation of a humans perception of statistics… and volcanoes hate statistics.

    • Thanks for the info… very good indeed. Enjoyed hearing about their system and event tree. Best! from Alaska which is experiencing very warm weather… Note to Japan…. thanks for all the leftover typhoons… makes it warmer here. motsfo Very off topic but who here can get ‘Windy.com’ ??

    • Well actually 2C is warm for here…. usually it’s closer to minus 12C now. And i have seen minus 35 F to minus 50 F but the later is murder… hard to get oxygen out of the air… i digress.. anyway my dd was showing me ‘Windy.com’ and i wondered if everyone can get it or is it just in the US… ?? and Redoubt is cloudy. (gratuitous volcano ref to make this legal.. 😉 ) Best!motsfo

  4. I have to confess Neil and others are right – the Agung Seismograph is clearly showing daytime human activity. Must be the all-day disco at the Mountain Observation Post.

    I am intrigued by the unusual quake shown on the chart at 20:31 Bali time. Either deep, distant, or more likely magma forcing passage? Also, some of my tornillo pals are active today.

    I don’t think Agung is ready to be put aside just yet.

    • I agree on all 3 points.
      It is undoubtedly quieter, but there are conflicting signs as well. Until some competent person investigates the site or its environs I will remain convinced that there has been a low level of ash emissions as well as steam in recent days, and about 20 hours ago I watched the summit showing the highest level of activity I’ve seen to date.

      More tentatively, throughout yesterday, morning and night, I was seeing small events of a certain signature every 7-8 minutes

      . They are still there, but much less noticeable and with a few gaps today.

    • Could the ‘human activity’ shown on the daytime seismographs have anything at all to do with the proclivity of the locals to use motorcycles of various capacities at all? I am just wondering because of the excessive amount of motorcycles I have noticed in recent videos in Bali. Having had a brother who in the 1960’s was addicted to noisy motorcycles, I wonder if the seismographs have been affected in any way by these noisy vehicles?

      • It’s not just Bali. I had an acquaintance in Phuket that survived the tsunami (which took out his shop) only to be killed in a scooter accident about 2 years later.

        R.I.P. Tracer0

        • my mom had an old friend who beat cancer and was killed in a car accident 6 months later. Driving is one of the most dangerous things we do i guess.

  5. M5.7 in the Arctic ocean, at 86.8N. Close enough to the pole that is falls outside the USGS world map!

    • i can get it Albert but i have to back up until i can see 3 Africa’s and 3 of everything else too.. Very good catch… i”d have missed it… 😉

  6. I more than agree with Neil , Alcide Cloridrix, (interesting name to choose!), I am English born and bred and would never have realised you were a non-native speaker if you hadn’t mentioned it! I also agree that you have a far better grasp of English than sadly many younger members of the English race. That aside, I found your your post above, very interesting and informative! Many thanks! I also agree that whilst Agung MAY possibly be writhing in it’s death throes, I personally feel that this volcano definitely need watching as things aren’t always as they seem! As for Dr Johnston at Mount St Helens I have always felt that it was so sad that the one man who was deeply worried about what that volcano was capable of was the one to perish in such a sad way! Such is the life of a volcanologist I suppose. True heroes in my opinion! I will never forget watching that volcano to it’s very, very sad conclusion! I am just thankful that at least that man’s total sacrifice to volcanology was remembered in the naming of the Johnstone Ridge after him.

    • Oops. I seems to have lost my way from the original reply to Alcide Cloridrix, way, way up the page!!! Put it down to age but not experience! 🙂 😉

      • No problem, things move fast on the blog…

        By the way, I chose Alcide Cloridrix as a name, because I have a bit of history with chemistry, back when I was a student…. And hydrochloric acid is indeed a volcanic gas, just ask any of those poor guys mining sulfur at Kawah Idjen, where it’s deliciously mixed with all kinds of sulphuric stuff in the fumes they breathe (and in the lake water too!)

        Based on what I read online, the stuff in the lake is a 50/50 mix of HCl and H2SO4 with a pH of 0, it can take down steel cable, and the fumes at the sulfur mine are nastier still. No wonder those poor guys don’t make it past their thirties..

    • “As for Dr Johnston…”

      Even worse, he was one of the main voices putting out the opinion that it could have a catastrophic flank collapse. Yet he still took up his station at Coldwater II.

      From the Wikipedia entry on David A. Johnston

      “…fellow eruption victim and amateur radio operator Gerry Martin, located near the Coldwater peak and farther north of Johnston’s position, reporting his sighting of the eruption enveloping the Coldwater II observation post. As the blast overwhelmed Johnston’s post, Martin declared solemnly, “Gentlemen, the uh… camper and the car sitting over to the south of me is covered. It’s gonna get me, too. I can’t get out of here …” before his radio went silent.”

  7. Very insightful replies from all of you….

    Thanks a lot for telling me my rambling was at least somewhat understandable…. Very kind and nice comments. Merci beaucoup, c’est vraiment sympa.

    To tell the true and short story, we just don’t know what’s up with Mt Agung, as it’s giving out all kinds of mixed signals which just don’t make sense. Except one…

    There’s human activity right in the midst of the exclusion zone. That shouldn’t be. I agree people have to take care of their livelyhood on the flanks of the mountain, but that raises an added danger.

    Should the smallest thing happen, they will be straight at ground zero with no hope to escape. Even a VEI-1 explosion can launch a pyroclastic flow straight at YOU… If you’re in the wrong spot at the wrong time, well… game over.

    Meanwhile, at the VSI headquarters, I can imagine the pressure they might be under…. Mt Agung ,as it was so delightfully stated in the post above from “Ubud now and then”, now has his belly full with 18 millions m3 of magma. This stuff is there, and anything happening to the containment structure it’s in, may let some of it seep to the surface (provided it’s not cooled solid which may take a bit of time).

    Or it may quietly sit and simmer for a few days/months, and, when another impulse from below happens, it will ooze at the surface as a degassed lava flow. That’s 1963 all over again. Then, when most of this stuff will be pushed out, pressure will drop precipitously in the belly of the beast now filled with fresh, gas-laden magma ready to party, and things will get really interesting really fast.

    Whatever, Agung is definitely not in its death throws, although it’s suffering from a bit of bloating and indigestion. Will that evolve into full gastric pandemonium, the answer lies in an obscure Sanskrit spellbook from the God of the Mountain. And maybe in the hands of the great guys at VSI.

    • I absolutely agree.
      In fact I think a “failed” eruption is possibly the most dangerous possible scenario. It would be like sitting on a shaky train with no air conditioning on hot day with a case of aged, sweaty dynamite.

  8. Not seen an earthquake in this region before . There have also been two more 5.7 earthquakes earlier in the same region.

    Mw 6.0
    Region NORTH OF FRANZ JOSEF LAND
    Date time 2017-10-28 19:11:02.4 UTC
    Location 86.98 N ; 56.93 E
    Depth 10 km

    https://www.emsc-csem.org/#2

    • and yes… 3rd one today…. 2 5.7’s and the last one a 6….. What could be going on there???

    • I think it is on the Gakkel ridge, the oceanic spreading ridge that is the extension of the one in the Atlantic Ocean. It is not particularly active

  9. Is this what Geo was trying to simulate? This happened 10 hours or so ago at Mauna Loa:

    • Leave it to a volcano to cough up an exact trace to match the discussion. Note the clipping aa the signal exceeds what the circuits can handle, making a flat top on either side of the trace.

      • 🙂 🙂 🙂 How apposite was that lurk! 🙂 Interesting times ahead in Hawaii I think.

    • Can you point to the place on the USGS site where you can pick an instrument and drill down to the raw data from the drums? I used to look at these regularly on the old HVO site but since the ‘upgrade’ I can’t find it! Thanks!

      • Main page, Monitoring under the yellow advisory Mauna Loa label, click on a black triangle on the map.

        • Doh. I already tried that, because that’s where I expected it to be. But the one station I tried it on – SWR – didn’t *have* any drums showing – just station name and operator! I tried another station and it worked.

    • That was a *significant* event. I poked around and it was detectable over most of Hawaii – from the south coast to Kilauea to Hualalai to the north side of Mauna Kea. I’ll be very interested to see what HVO make of it in their next status update.

  10. This was an excellent article, and I had never heard the story of the blue suns over Scotland before. However (and I wish I could cite a proper source) I recall reading once about the “dark ages” having possibly been named so due to a significant frequency of sun-dimming eruptions affecting Europe. I suppose Iceland was the main suspect for that. Maybe somebody else here recalls reading the same article/paper too?

  11. Is the Magma site down? I can’t pick it up at all.

    No visible activity as yet on the Agung cams.

    • Can’t get on it either bit it keeps doing this. KVERT’s site does as well.

    • It was steaming really good at dawn, taking a break I hope, it just makes me nervous to see nothing but a bunch of pyromaniacs on the hill.

      • UK morning, I’m up and about again. And after seeing (for the first time in weeks , it seems) nothing at all 8 hours ago, it’s puffing away spasmodically again.
        It looks like a high wind there, which might explain the high level of noise on the plot. I expect it does.

        • When we are seeing ‘noise’ on the Agung seismo, the associated spectra looks to have a continuous 0.5hz fundamental frequency and harmonics. can anyone describe what harmonic tremor looks like on a fourier transform spectra? Does wind or wave noise create such sharp harmonics?

          • sorry, I mean there’s a 1.5hz signal at Agung not 0.5hz.

            I see that 1.5hz corresponds to the green line on the icelandic tremor plots during windy storms and 0.5hz would be the red magma is flowing tremor signal.

            I feel surprised how sharp the line is on the Agung spectrum, like a pure whistle at 1.5hz. Are people or wind so consistent?

      • Hmmm,,,,

        400m in diameter means about 30 million cu m or some 50M tons+.
        At 44km/s the energy is about 5 x 10^16 J, 1megaton explosive is 4×10^15J so an astonishing 10MT++

        This would make a bit of a mess if it hit.

  12. Question for the camera watchers.
    My preferred camera when it’s working is the one in the link below. Because it seems to show good definition and it’s about as zoomed in as it can be.
    But I don’t remember that deep notch in the skyline, just to the right of the steam vent. It’s always been there, but was it always that deep?
    It must be my mistake. That would be a lot of rock on the move and I’m sure it wouldn’t go unnoticed, but I thought I’d just check.

    • With all the EQ activity and the fact it’s a volcanic structure (therefore constructed of debris) i would not be surprised to see the occasional change in silhouette but comparing with the photo in BillG’s post from the previous blog i’d say no change. This notch looks to actually be the head of a valley rather than a gap in the main crater wall.

      • I should add that i agree that this is the best camera angle, it also shows how much human settlement there is near the volcano base and on the basis of all the nightime lights and daytime fires i assume it is not in the evac zone!

      • Thanks Swebby. Point proven, you are correct.
        It’s hard to see how some of those buildings and people would survive in the event of a large pyroclastic flow.
        I suppose there must be quite a bit of foreshortening in the angle.Especially when you factor in the size of the peak.

    • I really hope the alert level has been lowered for good scientific reasons and not for financial ones. I did read of the tremendous financial hit the government of Bali is taking from this emergency and I do know that these poor seismologists can be put under tremendous pressure from many different direction. However there is no denying that the amount of quakes has significantly dropped in recent days. I feel so sorry for the people affected by this situation, it must be very, very hard for them to make a decision now as to whether to return home or not to. If it was me I would be staying put in a refuge centre until I saw the Volcano no longer steaming and even then I would be nervous. Perhaps age has lent me wisdom, on the other hand it may be I am overcautious. I prefer to be overcautious and alive I think!

      • Well, another sunrise and guess what? NO steaming! I am finally thinking that perhaps they DO know what they are doing when they lowered that alert level. Give it another week of no steaming and I would think about moving back home if I lived in the exclusion zone! I really DO hope that this is the right decision and for now it seems it may be! Being a very overcautious individual I would stay put in a safe place for 2 more weeks. But one doesn’t reach my age without being a cautious individual! 🙂 For all those poor displaced individuals in Bali I SO hope this is the end of their problems! Watch this space seems to be my feelings at the moment!

        • Oops, spoke to soon, actually there IS steaming but MUCH less than recently! Must get to bed now, it is late and I need my beauty sleep. A forlorn hope at my age but I DO need SOME sleep. Night all.

        • The steaming has picked up now. But is clearly under less pressure than previously. The plume is mostly pretty solid looking, and fatter than yesterday, but it’s not gaining any great height.

          Does anyone know… Would I be right in saying that , assuming that Agung settles back to some sort of resting state…Is it now more dangerous (in a resting state) than it was back before this crisis started?
          Specifically, when the next intrusion pushes through, is it likely that, with an already well-charged chamber, the lead up to any eruption will be shorter than might otherwise have been the case?
          It seems to me that this might be true…assuming that it happens in the next few years, rather than decades or centuries, as that might allow time for the upper part of the system to cool and solidify .

          I’m also wondering what those single spikes are on the seismograph. I would guess , as it is clearly indicative with some event that has a very sharp attack and decay, with a reasonably big transient peak, that it might be some single splintering thing, as I think I saw a couple of days ago somewhere that such marks on the plot might indicate something like lightning strikes. There is certainly no lightning at the moment.

      • Do remember, that these volcanologists are some of the best in the world.

        • Thanks for the reminder GL. They most certainly should be! They have had more than enough practice!!! The only thing worrying me is could there be any political interference? Perhaps I am speaking from a western viewpoint but I do know that money HAS to be a major factor in such decisions! Sadly there is only a limited amount of money available for such VERY major problems and governments + tourist income can exert MAJOR pressure! Very sadly after 70 years of experience I have come to realise how expendable ordinary people can be in such situations! My grandfather fought in WWI and my father in WWII , they WERE viewed as expendable and I doubt very much has changed since then! I sincerely hope my worries are unfounded!

          • Wider and more dense steaming now also more vents on the slopes are also steaming.

          • There also seems to be a line of vents opening up across the middle of the volcano just under the darker part of the volcano.

          • I know clouds are there now but I have taken screen shots of what I saw earlier this morning but don’t know how to add them please could someone let me know how I can post them .

          • I haven’t watched that side for long, Janet, but I fancy you may be seeing an effect of the wind on the passing cloud, which may be getting sucked into eddies in the gullies and ravines on the flank. Interesting and maybe a little worrying if you’re right though.
            I’ll watch a while longer.
            I know it often seems windy there, but it really is blowing some right now.

          • Hi Neil I have been watching since 05:00 UK time don’t think it was clouds at all it was steam from vents I have saved the screenshots in my picture folders do you know how I can paste them for people to view.

          • I don’t I’m afraid. But if you have the exact local time on the screenshots, I may be able to roll the cam back far enough to get the idea. But if you saw it, you saw it !

          • Times are 14:30 03 14:46 06 (Bali Time) if you can try and look before these times from around 12:30 (Bali Time) lots of dense venting from the top from lunch time.

          • I see Beardy Gaz has answered your question on the screen caps. Thanks Gaz.
            Janet, unfortunately we can only scroll back 2 hours. It would have been interesting to witness the movement of the cloud. Never mind… I’ll watch for a short while.

  13. Mauna Loa. The earthquake activity is approaching the levels from before the previous two eruptions, although it still lacks the short burst swarms. The deep quakes close to the south coast of Hawaii could be where the magma chamber is being charged.

    The article at https://eos.org/features/volcanic-unrest-at-mauna-loa-earths-largest-active-volcano is worth reading. It finds that not all signs of an impending eruption are there yet and we are not that close to an eruption. On the other hand, two previous eruptions is not a lot to go on for finding a pattern. The next eruption may differ from the previous ones. And from the inflation, it may be that there is more magma available than last time.

    • OO, off to Hawaii…… only on the computer…. this old bad back isn’t ever going on a plane again…Just a note to the rest of You….. take that trip when You can; You never know when that door might close for good.

    • I’m not so sure about the deep quakes. From previous discussions I’ve had I think the conclusion was that these deep quakes are associated with the entire island ‘settling’ under its own weight.

      I do however agree that Mauna Loa appears to be inching closer to eruption.

      • That is certainly possible. But the deep earthquake have been located in this single area for quite some time now. If it were settling of the mountain, the quakes should have been more widely distributed. The map below shows the quakes: they are the close pack coloured blue-green at Pahala. The colours indicate depth, with red being shallow and green ultra-deep (30-50 km). There are a few deep quakes around the island, but nothing like this long-lasting cluster. It is also midway between Mauna Loa and Lo’i’hi, which is another suspicious aspect. At least, I find it suspicious.. The quakes at Lo’i’hi itself are less deep, 10-15 km.

        • It’s certainly open to debate. I recall seeing a similar cluster – perhaps not so extensive or persistent – of very deep quakes way up north near Mauna Kea a year or so ago. But I agree the Pahala cluster is an interesting spot and one I’ve drawn attention to myself before.

          • Hi, Mike… isn’t this near the “Big Crack”..?? and Best! to You, motsfo

  14. Bobs floaters have come in handy after all… (“Restolingas”)

    https://www.sciencedaily.com/releases/2015/01/150122084539.htm

    For those that missed it. Restolingas were the term given to the chunks of pumice from the vent we at VC called “Bob.” It was located just south and west of La Restinga on the southern coast of El Hierro.

    When sliced open, the restolingas had a vanilla icecream with chocolate swirl appearance. The dark material being juvinile, and the white material being mobilized silica mateial from the sediment underlying the island from before it was formed. The sediment was laid down when the Atlantic was still just an extensional basin. Based on lithostatic pressure, that sediment likely has turned into Phyllite since there is not enough pressure to form Schist. Evidently, what the scientists have found are the presence of micro fossils in the Restolingas, pointing to the conditions of the area when it was just a basin before the islands existed.

    • The remaining warning for Agung is:-
      Although the status of the Great Volcano activity has been lowered to Level III (Siaga) but it should be understood together that volcanic activity of Gunungapi Agung has not abated completely and still has the potential to erupt.

      They then go on to give further warnings to residents and visitors alike as to which areas are STILL off limits and what actions to take in case of eruption.

      So a lowered status but still with the caveat the it is everyone’s own responsibility to take all necessary precautions in case of eruption.

      • Seismo looking much quieter today, definitely another dial back in activity on that front.

        Do feel for the Bali volcanologists. The understandable economic pressures to have things returned to normal in the locality, coupled with the problems caused down the line of an overly cautious approach (i’e getting local populations to listen/move in future when an evac is absolutely essential) makes this downgrade in threat understandable/predictable. The flip side being – this is a big volcano still showing signs of unrest. Damned if you do damned if you don’t.

        Looked at the nigh time feed and there are now lights showing well up on the flanks of the mountain so people have clearly returned to areas that had been vacated. Neil mentioned that unless it was a trick of the camera angle, then some of the foreground buildings look mighty close to the mountain. I’d say that it is not camera angle – those buildings are indeed uncomfortably close in the event of a large event.

        • Swebby, you have just voiced all of my concerns for the people as well as sympathy for the volcanologists who must have the most difficult job in the world!
          The saying, “In between the devil and the deep blue sea comes to mind! I feel for everyone involved in this situation. Having read a little about the 1963 eruption it seems a somewhat similar scenario played out then. At that time it appears that after an initial scare things quietened down for quite a bit more than a few months before the big bang. Let’s hope that with modern seismological instruments they get sufficient warning to move before what I feel may be the inevitable eruption.

  15. On the facebook site there was a question on how dust can make a sun appear green or blue. You need specific size dust grains. Small grains are more effective at removing blue light (scattering) and make the sun appear red. Large grains affect all colours equally. But there is a size in between at about 500 nm, which acts funny, scattering blue light less than red. It is called Mie scattering. That causes the blue sun. (There is a more common situation where scattered light gives a blue halo around the sun and that os often reported as a blue sun, especially with dust storms, but it is not quite the same and the sun itself is not particularly blue).

    A green sun is a case where both effects work together. The normal atmosphere takes out the blue light, as at every sunset. The Mie scattering removes the red, leaving a green sun. It makes sense that it is mainly seen when the sun is low on the horizon, and that it changes to a blue sun as it rises. It is a rare event!

    • This reminded me of an article I read from NASA. In the 2020’s they plan on redirecting an asteroid in hopes of protecting Earth in the future should an asteroid head here again.

      Now wouldn’t it be something to find out there really is life out there when aliens come here because we’ve destroyed part of their planet from this experiment? 😀 I apologize if my comment has offended ET, etc…

      https://www.nasa.gov/content/what-is-nasa-s-asteroid-redirect-mission

    • Thanks, Albert! sometimes i wish this site just had a “like” button… Consider Yourself pushed.. 😉

  16. If there is a reader who knows meteorology, (s)he may be able to clarify something. In the recent literature, the tropical jet is discussed mainly regarding the Indian Ocean and Africa. But in Krakatoa, it is clear that it went around the entire world. Why is it not presented as a single stream in the modern studies? Has it changed or did Krakatoa perhaps coincide with a particular strong phase?

    It clearly is the same structure: the tropical jet bends north towards India and avoids the southern hemisphere. Indeed, the coloured suns were seen north of the equator, although Krakatoa is located south of it. It explains the movement of the dust in the first four weeks.

      • 30/10/17 22:37 GMT UTC
        Indonésia, A 7 Km De Lanta Timur
        Magnitude: 5.4 graus
        Profundidade: 120 km
        Energia: 1875 Tons de TNT

    • Hello Albert,
      first of all: it is a great pleasure for me to be a guest in your volcano cafe and to learn so much on volcanoes and other features. I am a silent reader since the Holuhraun eruption and loved to read every single article from all of you. Thank you very much for all those enlightening comments!
      Some ideas on your question from my side: I don’t think that the upper tropospheric features have changed significantly. May be it’s rather the understanding of their temporal and spatial variability that may have changed … and nowadays the tropical jet is more directly related to the thermal heating / convective systems in summer over central Asia and Africa, that is causing the strength of the jet.
      For Krakatoa I have another guess: since the eruption cloud went well into the stratosphere, there may have been some influence from the QBO (quasi biennial osciallation) phase … probably the situation was a strong QBO-East signature in the stratosphere at that time (could be up to 30 m/s), which could explain the ash to spread all around the globe and the ash was a tracer for revealing the QBO phase … just a guess, since there were no stratospheric measurements in the 19th century.

      • Thanks for the comment. The ash certainly reached the stratosphere and such an effect may have contributed. The velocities are a bit on the low side: the dust took 13 days to circumnavigate the world, and at 30 m/s it would have taken 15 days. The dust that caused the sun colouring is more likely to have been carried on the tropical jet. The white haze (sulphates) is a different matter: that would be stratospheric.

        • Hi, there is a nice analysis of zonal averaged wind speed at the equator on this link

          where you can see that in QBO east phase the average wind speed between 10 hPa and 30 hPa can reach up to 32 – 36 m/s (based on the the satellite records through past ~40 years). So if the eruption cloud went up to > 25- 30km altitude, and if the eruption coinceded with max. QBO East, then this could explain the circumnavigation within 13 days

  17. Quake about 200km East of Bali 5.4M 120km depth. 22:37 UTC. It is showing up on the Bali plot.

  18. That’s a hacking great big quake on the Agung Seismograph. Is that the one at Lanta Timur, a 5.4 mag quake? It’s a deep one at 120km.

  19. 2.1 under Örærajökull. Nice steady activity there.

    Oh and hello everyone. Been a while

  20. Öræfajökull has broken the scale for the 4th or 5th time this year(all but one extension of the graph have been this month), would be interesting to find out what’s going on there.

    • Open secret, its active again, togeather with Hekla (Vatnafjöll) and Bunga (Veidivotn ~ Holuhraun) and Grims (Laki). Can blow large. Think like Eyjo on steroids.

      Found in the dungeon of the ‘pending’ queue. Perhaps akismet objected to steroids? Have a cookie – admin

      • Grimsvotn seems to be having a quiet spell. Hekla though is quietly ramping up – there is a small but notable increase in earthquake activity over the months. It could fall asleep again of course. The lady is unpredictable.

        • Hekla has been ramping up for years in all fairness. I have a feeling that the pattern has changed in terms of how it behaves. Based on Hekla’s past history, it seems that the “patterns” chane fairly frequently. Time will tell.

  21. And meanwhile Agung is steaming heavily today, looks like a locomotive up the top of the volcano at the moment, but the steam is rising really high again also.

    • I noticed. It’s more intermittent, but when it puffs, it seems to have more pressure behind it than recent days.
      I’m still not at all certain it’s ready for sleep yet.

        • I think this is the area that Janet was looking at two days ago?
          I’d like to rule out human activity first.
          I wish I were more able to locate some of the smaller seismic events. That might give us some clues.
          But my first suspicion is definitely human activity. Let’s keep watching 🙂

          • It does look like the area I was watching the other day there looked to me like a long line of steam rising down the left hand side .

          • I’d also go with Human activity, but that really is well up the flank of the mountain. I wonder if they have logging operations around there as i’d prefer not to think that it is human settlement.

            Janet – i think i may have an idea as to what you were referring to the other day if it was the left flank of the mountain. It may have been low hanging cloud/mist in the valleys that happen to be on the windward side at that time, kind of like this http://wallup.net/landscape-nature-mist-waves-forest-valley-clouds-mountain-morning/ ?. I do remember a couple of weeks ago seeing this effect in that area on what was one of the damper days in Bali. I have to say my immediate reaction when seeing it was – is that steam!

          • Just to add – It could be very tricky to tell the difference between valley cloud and minor venting if it does occur on the flanks – just dug up this photo of pinatubo so it is always worth checking for opinions on the forum if you do see something.

          • I think this will resolve itself in a matter of a few hours.
            This is how I see it.
            We’re seeing it from a considerable distance, and if we’re seeing it, so are the local experts. As we’re seeing it from several km distance, if it IS lava, it’s not an insignificant amount and it might also suggest a very real possibility of a flank eruption, which they will take as a very serious matter.
            NOT one to be ignored.
            So let’s see if they take any steps over the next 12 hours or so.
            The truth will out.

          • That light source winked out at 11.44 pm local time. From the manner in which it disappeared it wasn’t clear to me if it was someone switching out lights, or cloud coming in between camera and source. Cloud DID arrive at that time, so either remains a possibility.

        • If you were talking about the lights on the lower left flank of the volcano, there is a temple and car park located there which is of high importance to the Balinese. It survived the 1963 eruption. I believe the temple is not currently staffed. I looked just now and the lights are now out. I gather it is the nearest structure to the main volcanic cone.

          • I just looked, and the lights are visible again. It is the Pura Pasar Agung Temple and is scarily close on the flanks of the volcano.

          • Now it is clearly HUMAN activity and nothing volcano related… sadly!

          • However, as Clive says, worryingly close to the risk from any future eruptions! Let us hope it never comes to that! Surely 1963 taught them SOMETHING!!!

      • Looking at the videos of the crater interior posted by the mad frenchman and slightly less mad Bali monks, i’d urge caution in interpreting the steam plume apparent above the crater rim as something that is being ejected under pressure. From what i could see, there is an area to side of the crater base, covered in rockfall, where a lot steam/fumes/vapour is billowing up from. This plume of vapour flows up the side of the crater wall (the height of which i’d geusstimate as being at least 200m) before becoming apparent to us on the camera. At this point, it’s appearance on camera is likely to be very dependent on the weather on the top of the mountain – e.g strong cross winds, humidity, angle of the sun etc. I mentioned airplane contrails as a similar example and how they can vary from short ephemeral affairs to long streak from horizon to horizon depending on atmospheric conditions. What i would look for is if the steam plume starts to appear from a broader area along the rim as this might suggest that new sources have opened up within the crater.

        I’d certainly agree that Agung may not be quite ready for a sleep yet, but is it minded to get out of bed in the near future?

        Good article posted by Frances further up, balanced and a good take on the current situation.

        • I think we have to accept that we don’t know much about what’s going on, or its previous eruptive history and the clues that may give us regarding how this is likely to play out.

  22. Dinosaur winter:

    http://www.bbc.com/news/science-environment-41825471

    (This may need a bit more work though. If everywhere dropped below freezing for years, it is hard to see how birds could have survived. A lot of water would also have been thrown up, and that could perhaps have affected the temperature balance. Water is a powerful greenhouse gas. )

    • A recent new scientist or sci am article discussed a group of birds that spanned the extinction event and these seemed to be fishing seabirds. In arctic climes these happily survive in similar environment today.

    • Correct me if i’m wrong; isn’t the Dailymail kinda of a scare tactic headline grabber and perhaps to be taken lightly until further investagation by other sources (from motsfo before the first cup of coffee)

      • Huge Grin! You got it in one motsfo! Hardly the most reliable source of any information at all! They invariably cut and paste a load of rubbish from other websites and cannot even spell properly most of the time. Sadly though, one of the few free newspapers online. Even the BBC news site is no longer the unbiased source of news it was in the early days of the internet. There is a reason the Daily Mail is known, less than affectionately, as The Daily Fail!

      • Yup. Indeed. The Daily Fail and all its siblings, are no reliable source of information. They’re tabloid clickbaits, doom-and-gloom prophets of the Cult of Fear-Mongering, whose livelyhood depends on the fact they can sell clicks ie viewing space to advertising firms.
        This is no information, this is drivel to push us into clicking that link on an emotional response, so ad companies can shove whatever sh….tuff they want down our throat.

        Nasty.

        • What a slight on UK national newspapers.

          Rubbish. The Daily Mail is the epitome of high quality and utterly reliable reporting by highly qualified reporters with an in depth knowledge of their subject.

          Trouble is their subject knowledge is never coincident in any way with the article they are reporting.

          • Spot on. They don’t know a thing about what they’re talking about, but they’re doing it in style.

            Reminds me of ..*cough* politics 😉

    • My sister has lived in Spain for many, many years now. The Spanish laugh at the hype over the Canary Islands. So far these quakes are very small! Yes they are currently of interest to volcanologists and Geologists but they could easily all just go away with no real problem ever being felt. As far as I am aware, no-one living on the island where these quakes are occurring has even felt one of them, they are so small currently. Well actually, I say currently, but the last time I checked was last week, so I am happy to be corrected if anyone has updated info on that.

      One needs to be aware that the Express makes the Daily Fail look like a moderate, non-alarmist newspaper! Just check out all the UFO articles and the fact that EVER winter they forecast, ‘in their words’, SNOWMAGEDDON for the UK and for the last 10 years we have had those headlines it has been among the mildest winters on record. Hyperbole and the Express go hand in hand! If you don’t believe me, go to their website and look at the amount of UFO and Aliens articles they have. They are just a comic!

      • Tragi-comic instead, for lack of better words… Stuff like that should not be named newspaper, it’s just prolefeed laced with poison to make people react. And watch that ad peddling cars/phones/useless junk du jour…

        People kept in constant fear are avid consumers. That’s the gist of it.

        My 2 cents…

  23. “just a comic” nice shorthand for ‘not accurate’ but don’t let the people who love comics hear You.. 🙂

    • Right now mountain top clear enough to see grey emissions from the volcano Agung

      • Definitely looks like two separate emissions, dark smoke and white steam and a lot of both!

        • Steam to the right side and sometimes the front of the crater, dark smoke to the left and sometimes behind the white steam, smoke belching heavily and higher than the steam.

          • OH DEAR! Sorry, I transposed right and left there. Always had a problem with my right and left! Got told to turn right on my driving test and turned left! Examiner NOT happy but I still passed. 🙂
            So to try again, steam to left, smoke right!

        • Ok Gaz, I’ll just work through and see which are working. Some seem intermittent, and some only seem to function during the daylight hours.
          This is definitely working.
          https://www.youtube.com/watch?v=IuLYXxOFNSo

          Also working.
          https://www.youtube.com/watch?v=P4_thf1dZ7M

          This one tends to work only during daylight hours and seems to be on the other side of the mountain. Useful when the weather closes in on the others.
          https://www.youtube.com/watch?v=I9Sptgjxcgc

          The one with the best view doesn’t seem to be working at the moment.

      • I’ve just had my first look at the cameras today, and it does seem to have been producing a much more substantial column than at any time over the last week.
        Smoke? Steam? I can’t tell, but there’s certainly quite a bit of it.
        I also think that the daytime noise on the seismograph seemed much more active than normal over the last 12 hours, but not in such a way yet that I can read anything into it.

        But I’m mindful, given the weather conditions, that today we might have atmospheric conditions more suited to creating more visible clouds.

        • Can one of you guys provide an updated list of working webcam links please?

          • Also this is a live streaming site with two cam views and seismograms along the bottom, also satellite which did earlier this morning flash red and yellow alert for ash/dust.

        • Neil I watched it for a whole hour until 30 mins ago, (it was mesmeric:) ) It was most definitely smoke as well as steam because as the sun went down the clouds and steaming turned pink, the smoke stayed as dark as the mountain!

  24. I was idly watching the video linked above (thank you Frances) and the steaming is coming from what looks like a landslide heap to the side of the crater. Then I thought: that looks more like a lava dome, an intrusion that just happens to look like a landslide. Some of the sides are oddly steep. And why would a landslide steam?

    I put a picture here: https://ibb.co/kZerHb partly because I have a cinema-scope wide screen but partly because I have no clue how to put one in my message.

    If this is the top of a magma intrusion, Agung may be pretty much primed to go.

    Thoughts?

    • my thoughts, for what they are worth Clive are that you may be on to something!
      Initially the steaming was only coming from that one side that I also had assumed to be a landslide (still could be one supposes) but later the steaming also started on the other side of the crater.
      At 16:22 on this Seismo,
      https://magma.vsi.esdm.go.id/live/seismogram/
      one can see a VERY tiny increased thickness of the line, watching on the above linked live streaming You-tube site they have seismos for various distances, first one is very local to Agung and on that one there was a noticeable small quake. The other seismo streams didn’t record anything. I am hypothesising that the small blip MIGHT have been something moving in the crater. It was after that that the smoke became noticeable. SO, possible the landslide could have shifted allowing smoke out and the other side was still steaming! As I say, that is just a totally unconfirmed guess of mine and I await with interest tomorrow dawn there.

    • I do see what you are saying Clive, unfortunately i certainly do not have the knowledge say one way or the other, hopefully someone on hear will be able to offer an informed opinion.

      Whatever it is, i’m curious that the emissions are to the very side of the crater and that some of the vapour even looks like it might be omitted from a fair way up the crater wall (although it is not easy to confirm this bit 100% from the footage). The asymmetry may be nothing more than heating of ground water that has collecting in an uneven manner, but… could this indicate that the intrusion or weakness allowing the vapours to escape is not actually located centrally under the crater? And if so… would any future eruption now be more inclined to occur outside of the main crater?

  25. My apologies if this has been discussed before, but is it possible/likely that the reduction in seismic activity at Agung is due to a lava vent having opened? That bright spot the last few nights sure looks like something pouring out and down the side of the mountain.

    The shorter version … does seismic activity drop when magma reaches the surface, but doesn’t explosively decompress?

    • I think we can lay the thing about the bright spot to rest. It’s a temple.
      About the other thing. I’m the wrong person to answer that.

      • There is a lit up temple on the side of the mountain? Yikes. They must know something we don’t … or maybe the temple actually controls the volcano? That would make sense.

        😉

        • Yeh.
          Could someone email them and ask what time the eruption is due to start?
          Then I could switch off the camera view and maybe do some work

          • 🙂 🙂 I couldn’t stop watching it this morning! Now back watching the live stream and wondering if it is raining heavily of just the ash whirling from one of the ubiquitous bonfires. I reckon bonfire as they always seem to have one around this time of the evening.

        • Inside the Temple there is a big switch. To the left it says: “Sleep”. The middle setting is “Rumble” and the right setting is “Erupt”. There is a set of drums nearby for priests to fool us all with bangs and shakes…

  26. i guess my experience with Redoubt (my local volcano) paid off…. i knew that was a dome the first time i saw it, not a landslide….. and occ it still steams from the weather changes on the wintery mountain. But these are fumes not steam coming off the dome. Best!motsfo

    • Thanks for putting that link on there Bjarki
      WOW< I hadn't realised that it could be such a destructive volcano if it chose to go off! I just assumed it would be another relatively gently one like Eyjafjallajökul. Not good at all if that continues it's current unrest then!

    • Today’s activity seems harmonicish … jeeze I wish I could spend a few years getting a degree so I could learn to spot actual magma movement instead of just wondering if that non-triangular wave form represents steam, water, wind or a local youth with a new toy jack-hammer.

      … looks wet no?

      • not an expert but I think it needs to go crack then hiss to be ‘wet’

        so if you imagine your pipes in the house make a ssshshhhhhshsh type sound
        and with the tap turning on upstairs you hear KsssshhhhSSSSSHhhshshsh

        rather than rumblerumBLERUMBLErumbleRUMble

    • Örafæjökul eruption in 1362 was 10 km3, that´s a VEI6. It ranks amongst one of the largest eruptions in Iceland in the past 1000 years, but it was a quick eruption (just a few days) and most ash was deposited out to the sea southeastwards. Much pumice from that eruption is still visible nowadays in the southern flanks of the volcano.

      Just to give an idea, that eruption was 10 times larger than the usual big Katla eruption, and about 3 times larger than the largest historical Katla eruption in 1755. Compared with Eyjafjallajokull, the 1362 eruption at Örafæjökul was 50 times stronger.

      • Strangely enough (and it´s about second time I see this), the earthquakes at Örafæjökul appear in the ring-faulted manner, around the edges of the caldera.

        That seems to show the weakest point is the lifting of the plug of the caldera.

        This is similar to what is going on at Bardarbunga.

        Both volcanoes are the tallest mountains in Iceland.

      • The entire area of Vatnajokull seems to show considerable inflation in 2017.
        This is probably due to the hotspot arrival of magma at the crust.

        This is higher at Bardarbunga (4-5cm), Grimsvotn (3cm), and inflation is also clear at Örafæjökul (2cm, including also lateral movement)

        http://brunnur.vedur.is/gps/oraefajokull.html

        I would guess next volcano to erupt in Iceland will be one of these.

  27. Just seen the vid of he sacrificial cow at Agung – I wonder if it being chucked into the crater registered on the seismo!?

    • I saw the video also, I thought it was a goat but could be wrong. I was horrified that they untied it and chucked it into the crater alive!!! Why couldn’t they have killed it first! Poor thing bounced a lot of times before reaching the bottom and finally laying still. Most likely with it’s neck broken from the tumbling it took! Horrendous!

      • Crikey, I had assumed that it was already dead on the news report i saw, but looking again, maybe not! I’d not want to drag a live cow/goat up to the edge of a 3000M crater rim, that would almost certainly end badly for someone other than the goat!

        • The Balinese are a delightful people but many do believe in Hindu gods of a rather primitive type and that Agung is a god. The standard practice for humans in many areas (including mexico and the andes) is to sacrifice to the gods hoping that this will placate them.

          This usually works, but occasionally not.

          Education is the cure.

          • Sadly the magma inside Agung doesn’t give a flying bleep about the fate of that poor goat….

            If it can help people feel safer… Do it, but with vegetables instead 😉

        • You realise those videos are a month old, right?
          If you’re saying he went up after the priests, I take that to mean he went up after the priests that went up at the start of last month, not this morning.

          • Oops, I thought it was yesterday! I got caught out by the date at the top that says Nov 2nd! So sorry about that!

            It appears the priests make a habit of wandering up and down the mountain then! No wonder they looked fit in the video of them throwing that poor goat into the crater. No expensive gyms for them then.

  28. I am not sure how to post an image on this site, but have uploaded an image from early October at Agungs crater. Clive’s post sure looks like the start of an extrusion.

    Fixed the link. It is important to give the link to just the image, not to the page with the image on. It will only display the image if there is no scripted wrapper, to avoid malware – admin

    • Just looked at those two photos side by side! A big difference in the two and that heap of what I am now sure is cinder has certainly grown a lot in size.

  29. https://magma.vsi.esdm.go.id/live/seismogram/

    Hum hum… Something seems to be happening…

    Unless these priests with drums are throwing quite a party to fool us all, looks very much like the start of harmonic tremor… Way more activity than yesterday at the same hour, and it keeps building up and up and up… Uh oh……..

    Did the VSI dial the sensivity of their devices WAY up, so we end up listening to a croaking toad on the top of the seismo box for hours? Or is it something, this time, truly coming from below?

  30. All the webcams seem down, anyone got one for Agung that still works?

  31. A particularly heavy column rising from the crater today. But a fairly obvious storm coming in, which might explain the noisy seismograph.

    • Looked like it was just regular cloud formation behind the mountain. Watched it for 30 minutes or so and it followed the same pattern as cloud formation all around the mountain.

      • Yes, difficult to make out the column from the heavy cloud which was wrapping around the mountain, and seemed to be moving toward the camera. That has now cleared, and the plume is in plain view. It’s not as heavy as I thought it was when the storm clouds were around. But it is still more visible and seemingly stronger than it has been since about the 20th.

        However, that may well be because the storm poured water onto hot rocks. I suspect it’s nothing more than that.
        I’ll continue parading my ignorance and sticking my neck out as I said I would, in the hope that others can learn by my misjudgments…. But here goes.

        We’re just watching a simmering pot, and the steam rising off it. Nothing more than that. Every time one of us thinks they see evidence of something more than that, be that “lava”, “new vents”, “harmonic tremor”, or “ash”…. No disrespect btw… It helps that we say what we see and allow others to offer a view on our interpretations…. but it seems that every time, this gets dismantled by further evidence…. I don’t know about the “lava dome”. Maybe… what do I know of such things?
        Based on that, I think Agung’s trend is a settling one. I trust the local experts. They don’t want people killed on their watch , and they seem thoroughly professional to me.

        They qualified their statements about the status of the volcano with notes of caution and concern. If that’s good enough for them, it’s good enough for me.

        I don’t want this one erupting, truth be told. It isn’t way out in some desolate and isolated wilderness. It has to vent, but I hope that the local population can heed and respect any warnings.

        • Neil (et al), keep formulating the theories/asking Q’s if you see something you are not sure/suspicious of. Tis the best way to learn.

          I started following this forum back during the build up to the Holuhraun eruption, while watching the excellent Mila web cams. I spent a month thinking every dust storm, thunder cloud, etc could be an eruption but the comments from the more experienced posters on here eventually gave me an inkling of what i should be looking for. Yet despite 3 years of experience I’m an absolute novice. So if someone asks a Q that i’ve not thought of, and someone else answers, i then get to learn more!

          • Cheers Swebby.
            I started at about the same time, mostly reading.
            I’ve been surprised by a few areas where I have transferable skills, such as sound recording being able to help me understand drumplots, and other areas of knowledge I know a reasonable amount… soil science (I’m RHS trained… couple of Chelsea flower show medals to my name) and tidal regimes. Even an understanding of constructing legal arguments (given that they are evidence based lines of reasoning)… It’s all proved useful.
            And now I’m doing as you suggest, based on such knowledge and evidence as is available to me…. Establish hypothesis based on what I think is the best available evidence, and if it seems to stand up, I’ll put it out there and see if it survives.
            And if I do it in plain sight, everyone gets a chance to learn from it, if they didn’t already know. I really don’t mind being wrong if I can learn something from the conjecture

          • I’m a beginner too. Eyjafjallajokull was when I cut my teeth with Jon’s Blog, and followed Carl when he set up this blog. Jon is incredibly knowledgeable on Icelandic volcanoes and he’s the one that got me interested!

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