White Island

/ 10/12/2019

The Bay of Plenty is an evocative name. The Bay is sandwiched between the two northerly peninsulas of The North Island. The name includes the adjacent land region, so this is a Bay you can live in. The geyser of Rotorua is world-renowned. So are the adjacent Taupo volcanoes, although not quite as widely publicised. Too many of the Earth’s largest volcanic eruptions of the past million years have come from here, the most recent one around 100 AD. Since humanity arrived here there has been one notably eruption. The region is quiet now without any sign of impending activity. GPS measurements show deflation across the region which is a positive sign for those who like their volcanoes scenically quiet.

But there is also activity in the Bay itself, and it is centred on its main volcano, White Island. This volcano seems designed for tourism. It is partly submerged, so you don’t have to climb the summit – the sea carries you. The crater rim is breached on one side not far above water level – so a short hike brings you into the caldera. And there are wonders to be seen: steam rises from a crater lake, and yellow sulfur is deposited all around you. This is Dante’s Hell without the inconveniences. But this volcano has two faces, and this week we saw its unpredictability.

Geology

East of The North Island, the Pacific Plate is being subducted underneath the continental crust of New Zealand. This happens over a 3000 kilometer zone extending to Tonga, but only here is the subduction underneath a continent. In New Zealand, it has given rise to the Taupo Volcanic Zone. North of New Zealand, in oceanic crust, this becomes the Havre Trough. The two are offset by some 50 kilometers, and this offset is accommodated by echellon faults. These echelon faults are about 20 kilometers north of White Island. South of there, the Taupo zone has formed a graben in the Bay of Plenty. It is about 40 kilometer wide, and is bounded by two faults: on the west side runs the Tauranga Fault Zone, and on the east side of the graben is the White Island Fault Zone.

from J. W. Cole, T. Thordarson and R. M. Burt, Journal of Petrology, Volume 41, Pages 867–895 (2000) . In the insert, the dashed line shows where the fracture zone ends.

Volcanic activity is centred on the eastern fault, and his fault runs all the way to the legendary volcanoes of Taupo itself. This chain of volcanoes runs from Whakatane seamount on the edge of the continental shelf to Ruapehu, with the Taupo volcanoes located in the middle. There is an interesting change in the magma properties: while the central part has rhyolitic eruptions, the volcanoes on either end do andesitic magma.

Under water, there are a number of small sea mounts near and beyond White Island. The mounts are associated with the Ngatoro and White Island ridges. White Island itself is flanked by two sea stacks, on either side, Club Rocks and Volckner Rocks.

From Knight (2006),  Science of Tsunami Hazards, 24

White Island

The Māori name is Te Puia o Whakaari. I will be using the English name as being more recognizable, but the Māori name should probably have precedence. White Island is the emergent summit of a submarine mountain covering an area of 16 km by 18 km. The total volume is at least 78 km3. The base of the volcano is 300 meters below sea level, and the highest point is 321 meters above sea level. The island is about 2km in diameter. The two flanking sea stacks are part of the same submarine mountain.

from J. W. Cole, T. Thordarson and R. M. Burt, Journal of Petrology, Volume 41, Pages 867–895 (2000) .

There are two overlapping stratocones in White Island. On the west side is the extinct Ngatoro Cone, 310 meters tall. Most of the rest of the island is taken up by the younger Central Cone, which is active and which has a number of vents and craters. Ngataro is heavily eroded and may have been lost it summit before the Central Cone developed. The main crater consists three separate structures, one of which has broken through the crater rim and now allows easy access to the crater. The crater floor is only about 30 meter above sea level. All current activity happens on the northwestern end, furthest from the sea.

The crater rims shows a succession of lava layers alternating with pyroclastics. It appears that this volcano goes through cycles, where a phase of lava eruptions is followed by a phase of explosive eruptions, both phreatomagmatic and strombolian eruptions. The cycle has been suggested to last some 1000 years.

The magma chamber is probably located around at 5 kilometer depth. The composition is mainly mantle derived, and is magnesium-rich, but there is a component from crustal melt. It has been compared to that in southwest Japan. The melt probably originates at the subducted oceanic crust which here is some 150 kilometers deep and is strongly hydrated. It rises rapidly to the 5-km deep reservoir, where some mixing with crustal melt takes place. Prehistoric lavas seem to have a bit more crustal melt than the youngest (1977) lavas.

The conduit to the surface is not open. It seems blocked by a viscous plug in the upper kilometer. Small plugs of magma can occasionally rise rapidly to the plug but remain there, until eventually the plug breaks and a phase of effusive eruptions begins. While the plug exists, the eruptions are mainly phraetomagmatic.

There is no evidence for major eruptions from this site. It would be rare for significant ash to reach The North Island: this may be expected perhaps once every 1000 years. There is also no evidence that event here have caused tsunamis in the Bay.

Historic activity

The crater is currently in a phase of phraetomagmatic eruptions. Water circulates efficiently through the volcano, perhaps not a surprise seeing the low level of the crater floor, in the midst of the Bay. This water means that any rising magma would cause such explosions. Effusive eruptions would require the volcano to dry out, and this hasn’t happened yet.

In the early 20th century, a sulfur mine operated at White Island. This was a risky operation and there were several fatal accidents. In September 1914, a piece of the crater wall collapsed and formed a lahar in the central crater which reached the sea. All 10 people present and four of the five camp cats died. The floor of the crater remains shaped by the debris from this collapse. The ruins visible on some of the recent photos come from that mine.

Ruins of the sulfur mine

Since the first exploration in 1826, there have been regular small explosions in the westernmost crater. A lake is often present (it is a very wet volcano) which was temporarily drained for the sulfur mining. The explosions often leave small vents. There were larger explosions in 1933 and (probably) in 1946 which both caused small craters. Explosions between 1962 and 1971 formed three craters, which reached a depth of over 100 meters. After that there was a quiet interlude, until activity resumed in 1977 and tapered off to the 1990’s. The ash from the explosions was mixed with lava bombs: magma had intruded close to the surface. The lava bombs only fell in the crater: the explosions remained small on the VEI scale. After each explosion, the crater would be off-limits for a few days.

It is a very gassy volcano, and the sulfur and water combine to give a very acidic environment. Gas masks are recommended.

Small explosions have continued, most recently in 2016. The 2016 event excavated 10 meters from the crater floor and destroyed the crater lake. But the lake quickly reformed and grew quite deep during 2018.

Over the past decades all explosions were at a time no one was at the island. Until this week.

Was there any warning? There was an M5.8 earthquake on Nov 23, but at a depth of 120 km, this is unlikely to have affected the volcano. Going back longer in time, there had been a slow increase in activity over the past 20 years. A sudden increase to recent levels would have been a clear warning sign and would probably have closed the crater to visitors. A very slow increase is more likely to be ignored. There isn’t a clear cut-off point where a volcano becomes too dangerous, even when the warning level is raised – as recently had happened.

White Island is not particularly dangerous as volcanoes go. But being in a crater of an volcano with occasional phraetomagmatic eruptions, which happen without warning, is never safe. Volcano tourism should be done carefully. Carl has written about such tourism. And on the list of volcanoes best seen from a safe distance, perhaps this one should now be on it too.

As a final remark, Kilauea has also recently obtained a crater lake. It is quiescent at the moment, but once activity resumes, the water will likely make it explosive. HVO has a strong safety culture. Don’t be surprised if they start moving people back from the rim. It is for good reason.

Albert

And I’ll end by reproducing Mike Ross’ list of essential equipment for the serious volcano tourist.

I’ll give a little safety advice… my ‘gear list’ for fieldwork – may be added to or subtracted from depending on the volcano – and the rationale…

– Hard hat. Should go without saying! When to wear it at all times and when to merely carry it ready for instant use in case things go pear-shaped is left to the judgement of the individual.

– Satellite phone. Bit pricey but no excuse for not having one if you’re serious about this.

– Radio receiver/scanner. Can be useful to tune in to emergency service broadcasts etc. as well as normal broadcast news and weather.

– Gas meter. Doesn’t need to be precisely calibrated at vast expense so long as you’re sure it work. I recommend MultiRAE meters; they can be found on eBay and are good reliable instruments – we used them in hazmat work at the fire department. The ideal sensor combination for volcanology would be H2S, SO2, and O2. CO is not a significant volcanic hazard. CO2 is – but your alarm sensor for that gas is the O2 sensor as CO2 is an O2-displacing asphyxiant. The meter should always be worn on the waist belt in case you blunder into a CO2 pocket; it’s heavier than air!

– Thermal Imager of some kind. It’s good to know when something is hot! It can be hard to tell fresh and still very hot lava flows from old cold ones – until you get uncomfortably close! These days I would suggest the CAT S60 phone which has a built in TIC. It’s also a very rugged phone; important on volcanoes!

– Gas masks (plural). You need a range – different masks for different conditions. If there’s just a little ash blowing around a nuisance dust mask may suffice. If there’s significant SO2 around you may want to break out the proper respirator style make fitted with the correct ‘acid gas’ filters. And if things get really nasty you may need a firefighter-style full-face mask equipped with the same filters; it covers your eyes too – there’s no point in being able to breath if your eyes are so irritated you can’t *see*!

These are the more volcano-specific add-ons to the general outdoors/mountain gear you’ll need anyway.

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146 thoughts on “White Island”

      • Wow! That is worse then I’ve seen online. Gusts at 64 m/s at -6,7 deg. C is no joke. Apx. -25 deg. C. when you concider the windchill. Thank you for the link.

        Kråkenes lighthouse saw gusts of 42,7 m/s earlier today here. I got water in the basement at a rainrate of 8 mm. and hour an hour ago. 38 mm. in apx. 5 hours. Broken/flattened stormwater pipe… No damage fortuneately, and its less rain now, but must find someone with an excavator tomorrow. 3.000 mm a year (normal) here means it has to work properly. 😉

        Good article Albert. 🙂

        • No weather issues this morning, and no fast pressure changes. It was of course very bad weather yesterday so these may have been exhausted birds. Poisoning is a real possibility, though

          • It was very nasty weather here in Scotland yesterday, part of the same storm that hit Iceland.

            But in Iceland it was much much worst. There is one reported missing teen, that fell into a river. And a large part of Iceland is still with roads impassable, food supplies stopped, no electricity and no heating!

            That is bad enough.

            The following morning after the storm, nearly every road in Iceland was impassable. And still is in Akureyri (second largest city) in the north. About 200cm of fresh snow fell.

  3. Just in passing its worth noting that any unexpectedly large eruption of a krakatoan style would seriously impinge on the coastal area which is (for new zealand) quite densely populated. I doubt there is much in the way of tsunami warning systems in the area and although I guess all New Zealanders know what to do in an earthquake tourists probably do not.

    • Modeling has been done on this, but the potential tsunami heights that came out were not that high, even for an exceptional eruption for the island. The last major tsunami to hit the region was 500 years ago but it was likely generated much further away. Kuwae has been suggested.

    • There is a dedicated tsunami warning system for all of coastal NZ now after Kaikoura. Was in Tauranga this weekend and there was good signage. Our mobile alert system was tested across the country on 01 December or thereabouts. If a Kermadec event brought in a large tsunami there would be a lot of warning time.

  4. Sometimes I imagines a dacite dome or blocky flow..
    to competely fill Whakaari / White Islands crater
    Big steaming dark grey blocky mass fills entire crater

    Is that possible in near future?
    Article says the volcano is plugged and rather wet and hydrated and magma haves difficult to ascend

      • Composition of that dome I don’t think was ever determined, eruptions since before the recent tragic one were steam driven and the material was old rock, but the recent one seemed more ash laden so maybe new magma involvement or that plug/ dome collapsed? Lots of tremor now, very energetic on charts.

        • It seems more likely than not that there will further eruptions.

        • A lot of clipped signals on the drum over the past 18 hours, maybe this thing is going into full on eruption phase, with explosive ash eruptions? That activity is looking more than just geothermal.

          • I don’t think you can tell anything much from that drum chart – except that whatever is going on is doing it quite strongly. I’ve seen it look like that before a few times over the past 10 years – and sometimes it erupts, sometimes it doesn’t. Unfortunately the other publicly accessible seismograph is scaled at 500,000:1 so you can’t see much on that either.
            The RSAM SSAM charts span 36 days. I *think* the increase in amplitude of signal below 10Hz and particularly around 4Hz is suggesting increasing volcanic tremor since the eruption.

            https://www.geonet.org.nz/volcano/rsamssam
            There’s a guide to interpreting the charts in the “about” tab.

          • This seems like a similar event to the first 1995 eruption of Ruapehu, when skiers on the slopes were caught by surprise, Whether it goes on to steady and frequent ash eruptions like Ruapehu did back then for a time remains to be seen, but that last eruption seemed to be more ash laden then one’s from a few years ago.

    • Sounds like a change in temperature: water had become hotter overnight. It can also be pH but I would go for temperature

    • Such a sign on a highly active volcano like White Island, should deserve a shout “run to the boat”.

      As I become more aware of what happened, I conclude that the tours to the volcano were a highly dangerous activity, a bit like playing Russian Roulette. Changes of death were pretty high.

      Its very irresponsible that the tour operators were taking people inside the crater of such a highly active volcano with good changes of erupting at any time without warning.

    • Philip where is that incandescense in the photo?
      Cannot see it.
      If it glows, it means that fresh magma is extremely close to the surface!
      Maybe a lava dome will appear again?

      • It’s just to the very right of the photo, found at the bottom of the link page – the photo that contains the text (i.e, dated 2019 Dec 09 02:20 pm NZDT). (Unless the red colour is due to image colour distortion).

        • That’s a dimmed down right arrow to go to the next picture, caught in the screenshot by whoever grabbed that picture. Compare with the left arrow in another picture 😉

      • It is too wet for surface lava: that would need a lot more drying out of the rocks. If there was lava that close to the surface, there would be phreatic explosions on-going. The explosions have in the past excavated material from 100 meter below the surface, and that at that time was deep enough to expel lava bombs. I haven’t seen evidence that that has happened this time, yet.

        I do think that there is a significant risk of further explosions over the next months to years. I would not recommend to restart tourist visits anytime soon. If at all.

        • In 2012 a small highly viscous lava dome was extruded in white Island

          • Yes. I think that was part of the plug, the solidified upper part. It wasn’t big enough to reach to the magma itself, I think. The pressure from below was pushing out the plug. Those things can explode.

        • The cameras from what I understand use infrared for nighttime , so that light source has been visible at times for years. I think the spiny dome that appeared in 2012 is composed of viscous dacite magma and this is the source of these infrequent eruption events, that explains the sudden explosions preceded by very little seismic signature, tourists probably should never have been in a crater with a potential lava dome. This thing may rumble on like this for years or maybe start pushing into the crater or even potentially a more significant eruption especially if dacite or more evolved magma is present,? I hope they get a good sample if ash to analyse when they do the recovery mission.

          • Those images Philip Evans linked to are not nighttime. There is no light source nor incandescence in those images. It’s a navigation arrow. If you go to geonet webcams, for instance https://www.geonet.org.nz/volcano/cameras/whakatane, and click one of the pictures, you get a larger version of the picture. The entire left side of the image is a link to the previous image and the entire right side is a link to the next image. Hover the mouse over the image and a red arrow appears. Move the mouse off the image the arrow fades away. Since you can’t right click and save the image, someone has done a print screen, but not waited long enough for the arrow to completely fade away. Thus there is a faint red coloration in one of the pictures. Look closely and you see that it is in the exact spot as the navigation arrow. The shape is a bit blurred by the image compression, but you can still see that it is the navigation arrow.

          • When they are showing the crater cams, at nighttime in the past the hotspot in the crater was showing as a spot of light sometimes, at least a few years ago it was, if you are talking about the mainland cam showing just the island, well yes that would be something else. Understand now? Recovery mission using military assets is happening soon.

          • White Islands magma is extremely viscous! Hawaii and Kongos magmas are like liquid water in comparison

            Whats the viscosity of Whakaaris dacitic magmas in Pa.s ?

          • It is viscous because it is cooled. When in the cycle the plug is removed, the lava is effusive and not explosive. The magma here is andesitic. The dacitic component is likely minor and will quickly be washed out. There is no evidence of really large eruptions here, although explosions bigger than the one this week are certainly possible. Overall it is mainly a VEI-1/2 volcano.

          • An andesitic magma can be extremely viscous and quite fluid depending on temperature

            Soufrihere Hills had huge andesite domes and spines at 700 to 800 C making the magma just as viscous as ryholite.

            Hekla and Kilaueas Fissure 17 erupted andesites at around
            1070 C! Thats the hottest andesites ever seen erupted.
            They where as fluid as some cooler basalts like Etna and both formed spectacular lava fountains.

          • It is a subduction zone and the mantle below is relatively cool (1100 C at 60 km). Still, it has been suggested that the 1977 lava had experienced temperatures of 1200 C. Note that these are temperatures at depth. Rising magma cools due to the decompression, so it comes out at a lower temperature.

          • Well soufrihere hills was extremely explosive and dangerous, so I guess the problem is the viscosity of the magma. I remember in 2012 the GNS guys were not sure if the spiny dome was actual dome or just a plug pushed up, but really the point was something pushed it out and it was completely out character with white island activity of the last 100 years, any change like that should be taken seriously and was it taken seriously enough?

          • The dome formed after an eruption so presumably the activity was known at the time, and it was not out of character. It was always known that there was a risk of explosions. In my opinion, going into a crater which has explosions every few years is not recommended for anyone not fully prepared. But it is easy to judge after the fact.

          • Soufrihere Hills was mostly effusive lava dome construction with extremely viscous cold andesite lava it was the collapses that formed pyroclastic flows.
            And some ascent of gas rich magmas that formed subplinians and huge vulcanian eruptions

            I think the 2012 Whakaari dome was real magma ( the dome had blocks ) that means a cracking caparace over a stiff interior

            If it was a plug of cold rock
            You woud get a lava spine slab instead

      • Sorry but the officials bear a lot the responsibility for this tragedy.When dealing with the public, some coded, numbered warning system does not have enough impact, most people going to that island did not really know the true danger of even a small volcanic event, everyone relied on luck and the sporadic nature of volcanic events. Several times since 2012 there have been eruptions of various types occurring at night or when nobody was there, this circumstance was only a matter of time. The tour operators in 2012 took a while to tell geonet about the spiny dome, they didn’t even realise the significance of it. Nobody would be allowed to walk up to the Ruapehu crater at level 2 alert.

        • I wonder if part of the problem lies in the fact of Whakaari being in private ownership? Tourist visits to the crater being treated as a straightforward commercial transaction between the propeietor(s) and the cruise operators.

        • I agree this was inevitable; every trip into that crater is Russian roulette with very good odds – but if parties go in every day, sooner or later this was bound to happen. I’ve said that a few times, over many years.

          But don’t go blaming Geonet! The alert level system in NZ is all about describing accurately the *current* level of activity; alert levels have to be read in conjunction with the Bulletins, which describe possible future trends, and enumerate hazards.

          In NZ, Geonet has no regulatory role at all; they can’t tell people where to go or where not to go; they just provide accurate information.

          • The blooming newspaper posted regular updates, and shared what was happening in real time. Not official though, sorry

          • That was my understanding: there was no system in place that could have stopped the tourist visits. The warning levels have no regulatory power, the tour operators are independent and if any of them would stop running, someone else would take over. That may be the biggest lesson: a system needs to be developed that allows meaningful communication between the experts and the operators, and which has government support.

  8. Hello, I’m Alessandro, from Italy, the same Alessandro that in some previous articles opened a debate about the Tambora’s shape before 1815, forgive me this new out of theme, but I want to show you the result of our discussion on this theme.

    The Wikipedia page of Tambora in Italian is entirely made by me, and I’ve dedicated a paragraph about this theme, “la Geomorfologia”.
    https://it.wikipedia.org/wiki/Tambora

    The features of Tambora suggest one cone with one crater, a stratovolcano shape; in fact, the volcanology and also you substain this.
    But I’ve found the original Zollinger’s report (1855) in Google Books: https://books.google.it/books?id=W3FBAAAAcAAJ&printsec=frontcover&dq=zollinger+tambora+pdf&hl=it&sa=X&ved=0ahUKEwi90vHbirHmAhXnx6YKHYLiDUEQ6AEIKTAA#v=onepage&q&f=false

    Zollinger reported the witnesses of Bima’s inhabitants on two peaks of Tambora before 1815, a western and eastern peak, visible with the same prominence of Rinjani sailing toward to the east after passing Bali. However, it is also said that the mountain was conical before the great eruption (page 11).
    It’s described a cone with two peaks/summits.

    In the witnesses of the eruption reported by Thomas Raffles, instead, the rajah of Sanggar speaks oh three columns of flame near the top of Tambora, apparently from the verge of the crater: here, it appears that there was one summit with one crater/vent (all in the singular), the classic shape of stratovolcano sustained by the official volcanology and you (Fuji, Villarrica, Mayon, ecc…).

    How to reconcile this apparently contrast?
    In the wiki page of Tambora I sustain (thanks also to the contribution of Carl and Rob of Volcanocafe) that one of the two peaks wasn’t another cone, but only a high/great lava dome or parasitic cone on the only one volcanic cone, and the other the true crater from which rose up the three columns of flame witnessed by the rajah. In fact, the rajah spoke only of one top and crater.
    I’ve made the example of Popocatepetl for Ventorillo (or el Fraile) peak, or Fuji for Hoei peak. Naturally, in the case of Tambora, the second peak was higher than the two previous cases, more or less beside the crater, because the inhabitants of Bima were induced to speak of two summits.

    Petroeschevski, instead, thank that one breach at the rim crater gave the impression of a double summit. I’ve also reported this in the Wiki page of Tambora.

    What do you think?
    Alessandro

    • The only description that i would accept is that of three eruption centres within the crater, which means that there was only a single crater. There are no maps of the interior from before 1815, and strangely also no horizon profiles as used by ship navigation. This was quite out of the way. But looking at how the river valleys flow on the slopes of Tambora gives no indication for separate summits. The second peak may have been a parasitic cone, or it may have been a feature on the crater rim. but if anyone can find a map or drawing, that would be great.

        • Thanks! The maps came from sea traders, so will mainly show the coast. I guess the green parts are occupied regions where the traders had contacts.

        • Thanks, Rob! There are other maps in Google Books where Tambora was called “Aram Aram”, but they are not big deal!

    • I have found a geologic map of Mount Tambora:

      Here you can download the full resolution version of the map: vsi.esdm.go.id/gallery/picture.php?/95

      Volcanism in the area has switched location several times, first Labumbum was constructed to the southeast of Tambora, followed by Kawindatoi which is heavily eroded and forms the northeast flank of Tambora, it is not very prominent so it is unlikely to have been identified as a peak.

      Starting 190000 years ago activity shifted location again to construct Tambora, it grew a central stratovolcano aswell as numerous flank vents giving a shield like appearance to the edifice. But what seems more relevant to the discussion is the distribution of lava flows from the summit, for the oldest units it is hard to know but the pink intermediate age units, Tl 7 to Tl 10, are exposed only to the west while the red younger units Tl 15 to Tl 18 seem to only flow eastward and southward as if there was a mountain blocking these flows from spreding over the west flank, same as Kawindatoi not allowing younger lava flows to reach the northeastern coast. This would suggest 2 peaks, an older western summit and a younger eastern summit, but there is the problem of unit Tl 19 which could be maybe a reactivation of the western summit?

      My opinion is that it is hard to confirm from just geologic evidence the existance of the 2 peaks but if there are descriptions of the mountain having the two diferent summits, east and west then I think it is likely Tambora did indeed have two peaks.

      • Thanks, dare Devil! It’s the map of the great job of Wirakusumah and Rachmat (2017).

        Van Bemmelen in Geology of Indonesia I speak of a shiftment of the central vent that produced the second peak, but it seems to me improbable enough.

        I also thought to a somma edifice like the Somma-Vesuvius; in fact, an ancestral Tambora produced a caldera 43.000 years ago, the remaining of it was a peak and the new Tambora the other peak. But I don’t know how reliable it can be!

        Furthermore, I’ve found another writtem, where is said that the South(eastern) peak of Tambora was younger. I don’t know how the autor says it, but this would or could confirm the hypotesys of a parasitic cone/lava dome in the east. In fact, they are (naturally) younger than the main crater. Without to speak of another cone such as, for example, Gunung Api.

        For me, remains more likely the hypotesis of a second peak like Hoei of Fuji or El Fraile/Ventorillo of Popocatepetl. Or, even, Acatenango???

        Alessandro

        • The eastern peak covered in lava more than a third of the peninsula to a maximum thickness of at least a km at the caldera wall and spanned 10000 years of activity (according to the geologic map). It looks like a proper main vent of the volcano that took over when the west older summit went inactive, not a parasitic cone.

          As far as I know there is no evidence of a previous caldera of Tambora, it may have been an attempt to explain why the west half of the island was older than the east half. But there are no other ignimbrites in the island appart from those of the 1815 eruption and no topographic feature suggestive of a caldera either.

          • My feeling too. The rajah’s description seems most authorative. If there was a broken caldera rim, it could have looked like two summits from one direction and a single crater-summit from another.

          • I don’t know much about the context, where was the rajah viewing the eruption from? maybe only one of the peaks was visible from his perspective? maybe the columns rose from one of the summits (the eastern one most likely I guess) or he just chose not to be very descriptive about the shape of the mountain?

            I prefer the description of Bima’s inhabitants because it agrees better with the geologic evidence.

          • The rajah speaks of one crater though, since the western peak may have been eroded a crater may have only been discernible in the eastern peak.

        • I have a rather off-the-wall speculation about the three columns of flame. Remember that there had already been a sustained Plinian event five days earlier, and a second (smaller?) one that morning. So is it not conceivable that the summit region was already undermined, unstable and fracturing when the final paroxysm started?. With fractures providing ready and open passage for rising magma.

          BTW I wish there was more known about the Rajah. A true Unsung Hero of volcanology

          • Also the Tambora itself is unknown to be the most important volcano in the history, 🙂
            You should read something about Sumbawa on Internet Archive.org, there’s so much material!

  9. Due to bad weather/power cuts several monitoring stations in the North of Iceland are offline atm.

    There’s quite a bit of snow in Iceland atm, as this picture demonstrates, farmers are out digging their horses free.

    • Wow! Poor horses. Hard work! You should show this to English newspapers. They have some kind of mental breakdown if there is an inch of snow forecast here…

      Thank you for the picture!

  10. Whaakari / White Island is a really small volcano …
    even below sealevel its rather small
    how old is it? when did it start to form?

      • No, your number is not correct. White Island is on the continental shelf and the sea floor is less than 500 meters deep. There is about as much height below as above water, and White Island is therefore a small volcano. Fairly active, yes, but it is not known for major eruptions. Your number for the water depth refers to the sea outside of the continental shelf, but that is not the location of White Island.

      • Its just me thats been drowed by Hawaiis 18 kilometers tall and 200 kilometers wide monsters.

        And its me thats been drowned by the mammoth volcanic caldera – rift systems in Iceland

        So yea Whakaari seems rather small ….
        But Whakaari is just as intresting as any other volcano 👍🌋 and its also very dangerous if you go close to it

        • Again silly comparisons, it is bigger than it appears ,that is my point. This volcano is part of the Taupo volcanic zone , one of the most productive volcanic areas on earth in terms of volume erupted for a given area. Mt Tarawera is not large in terms of height but in 1886 it opened up a 18 km rift and produced a cubic km of basalt in a matter of a few hours..

          • Okataina and Taupo are absolute monsters, I dont think anyone here is going to deny that. But White Island is of a diferent breed, I cant check right now how tall it is, but either if it is 500 or 1000 m that is on the lower end for stratovolcanoes.

          • It is also at the far end of the volcanic zone, and has very different magma from Taupo.The magma supply rate is not that high but the magma get very easily to the upper magma chamber, so is still hot when it gets there. You get these heating episodes every few decades and White Island has increased activity. It is not a big eruptor. However, even minor volcanoes are far from safe.

  11. To Dare Devil: it is said that the rajah reached Dompo, soon afterward starts his description, but it doesn’t seem that he speake of his location, of his point of view.
    Your hypotesis, for which his description can depends only by his point of view, is to be taken in consideration, naturally together to the geologic evidence that you’ve illustrated, and for which i thank you!
    In the book “The eruption that changed the world” (Gillen D’Arcy Wood) the eruption of 10 April started by the western summit, but personally i don’t consider this description more reliable of a simple story.

    To Albert: also your hypotesis is really good, the same of Petroeschevski. Also the Rinjani has two peaks due to lower creater rim in the east. Try with Google Earth!

    Personally, as I said in my first comment, for reconciling the version of Zollinger and that of rajah (and of volcanology), we can sustain the existence of a single cone (Zollinger didn’t speak of two volcanic mountain, but of only one) with a main peak/crater at its top and a second peak on its flanks. Not two separated volcanic cones, such as Gunung Api. The examples, for me, remain Fuji (El Fraile/Ventorillo) and Popo (Hoei), but for Tambora the second (relative) peak was higher, beside the crater.

    • At most, I can accept an Acatenango shape, with two closed twin peaks

  12. So I’ve been following the activity around Kilauea, the boom of activity deep below Pahala, the slipping of south coast, and the curious tilting of the summit (almost like a lava lamp with a multi-day period). I downloaded some data from USGS of all the earthquakes greater than M1.0 from the past month near Pahala, summed the total energy for each day and plotted it:

    Comparing that with the Tilt at Kilauea summit, do you see a correlation?

    • I have tried to find correlations between the deep tremor, the brittle Pahala earthquakes and the summit with no luck. In the short term these diferent parts of the conduit seem to have their own independent cycles. I think that right now a batch of magma is rising through Pahala and that it will eventually get to Kilauea but at the rate it is going it seems it will take at least a couple of months if not a year or two.

  13. White Island two days ago (12 Dec) (Sentinel). Note the circling boat in the bottom right.

  14. Good morning, Thanks for your contributions about our discussion on the Tambora.
    Dust Devil, Can I put your hypotesis on Wiki page in Italian?
    Don’t be offended, but the Wikipage in Italian of Tambora is better than that in English😂

  15. IMO : Reykjanes peninsula – earthquakes during the last 48 hours

    Earthquake count:

    Magnitude less than 1 in all: 109
    Magnitude 1 to 2 in all: 79
    Magnitude 2 to 3 in all: 10
    Magnitude more than 3 in all: 1
    Total: 199

    • And just restarted with M3.9

      Sunday
      15.12.2019 19:48:12 63.888 -22.229 4.1 km 3.9 90.07 2.7 km SE of Fagradalsfjall

  16. ALBERT!!! SATAN HIMSELF DEMANDS YOU POST HIS GENIUS ARTICLE!!! OR SHALL HE BESTOW UPON YOU TEN PLAGUES?!?!

    You could also ignore me BUT THE FORMER IS MORE FUN!!
    Please?

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  19. There is a real glow now in Whakaari…
    Magma is close to the surface

    Maybe we will get a lava dome extrusion soon?
    2012 repeat?

    • There has been a specialists remark by IMO.
      “An earthquake swarm is onging by Fagradalsfjall on Reykjanes peninsula. The swarm started at 07:59 on the 15th of December with a M3,5. At 19:48 and again at 19:57 (same day) two M3,6 earthquakes were registered. More earthquakes followed with roughly 10 events with magnitude around 3. Over 1200 earthquakes have been detected in the swarm. IMO has received felt reports from e.g. Grindavík, Keflavík, Reykjavík area and Akranes. Earthquakes are common in the area.
      Written by a specialist at 16 Dec 15:55 GMT”

      Monday
      16.12.2019 01:03:47 63.878 -22.291 6.7 km 3.0 99.0 2.8 km SSW of Fagradalsfjall
      Sunday
      15.12.2019 23:26:50 63.876 -22.262 5.6 km 3.0 99.0 3.0 km SSE of Fagradalsfjall
      Sunday
      15.12.2019 23:10:56 63.876 -22.301 6.7 km 3.2 99.0 3.3 km SSW of Fagradalsfjall
      Sunday
      15.12.2019 20:17:46 63.885 -22.230 6.0 km 3.0 99.0 2.9 km SE of Fagradalsfjall
      Sunday
      15.12.2019 20:15:20 63.877 -22.233 5.0 km 3.0 99.0 3.4 km SE of Fagradalsfjall
      Sunday
      15.12.2019 20:13:50 63.873 -22.242 5.5 km 3.1 99.0 3.6 km SSE of Fagradalsfjall
      Sunday
      15.12.2019 20:13:26 63.883 -22.236 6.5 km 3.4 99.0 2.9 km SE of Fagradalsfjall
      Sunday
      15.12.2019 19:57:25 63.883 -22.244 5.0 km 3.6 99.0 2.7 km SE of Fagradalsfjall
      Sunday
      15.12.2019 19:48:12 63.881 -22.231 6.0 km 3.7 99.0 3.1 km SE of Fagradalsfjall
      Sunday
      15.12.2019 07:59:48 63.879 -22.228 4.6 km 3.5 99.0 3.4 km SE of Fagradalsfjall

      Credits IMO

      All the larger around 5 to 6 km depth.
      Iceland stretched one of its toes I guess 😉

      Looks like the swarm is fading at the moment.

      Station Krísuvik (IMO).

    • It’s a complicated tectonic setting with both transform faults and spreading. Here’s a good one pager summary:
      https://en.vedur.is/media/norsem/norsem_palli.pdf

      This swarm looks tectonic. Without any deeper analysis I would guess book shelf faulting along two parallel faults. Watch the region in the weeks to come. Strain release often propagates and sets of more of these swarms a few kilometres away.

  22. The solar minimum has been announced. We are now at the end of the last solar cycle, and the next one should begin within the next 10 months. This has been a cycle of very low activity. A tad of a problem for people who believe that a quiet sun means cold weather, as this cycle was also the hottest weather on record!

  23. The only trouble with the “Solar Minimum” is that it drums up the concept of the sun being somewhat cooler. Solar irradiance has only varied temperature-wise by two thirds of one degree Celsius since 1880 (NASA). Therefore a solar minimum is in no way able to cool or warm the earth beyond a tiny variation.

    My understanding is that increased sunspot activity produces more solar wind output and UV impacts on the upper part of the atmosphere. There has been a very slight correlation between Maximum and wetter conditions away from the tropics, which become slightly drier in these areas. The correlation is well within error range and could simply be ‘one of those things’ that looks like a correlation until more observed data is added to the prediction.

    However, generation of Ozone in the solar Maxima does lead to an observable slight warming of dry areas around the tropics. (NASA GISS)

    In short. Maxima and Minima don’t really make a lot of difference to the overall atmosphere of the planet apart from incremental alterations to short-term weather and temperature patterns.

    I’m sure Albert will correct me where I am wrong!

    • You don’t happen to be Clive Oppenheimer would you? Just curious.
      To me there is an issue with how people treat grand solar minimum, this is the only place where I have voiced my issues with anthropogenic climate change and grand solar minimum and not be labeled a denialist or alarmist(Yep i’ve been called both, I am the AVATAR!)
      (Insert intelligence insult here) like Tony Heller I think ruins the grand solar minimum argument for most.
      I could post some more links to some of my sources and maybe we could have a science off! If admin doesn’t mind.
      A decrease in solar irradiance from a grand solar minimum could have a more profound impact on the upper atmosphere there might be a more delayed reaction to climate and the potential impact of cosmic rays (Not on volcanoes.)

    • I did not find the relation between the little ice age and the Maunder minimum convincing. It is not at the level required for statistical significance (other people disagree with me on this). The difference in energy that the sun produces is at the 0.1% level, and that is too small to have an impact. Cosmic rays have been invoked but there is no mechanism through which they can affect the climate. And for the past 20 years, we have had a quiet sun and there has been no sign of cooling – at all. The people who predicted cooling 15 years ago have gone very very quiet. As for the 10th century temperatures, we are now well above those. We are also above the holocene maximum 6000-8000 years ago. The last time CO2 was at current levels, the sea was many meters higher than now. Welcome to the new world. We are currently on a trajectory of 5.5-6C heating by 2100. Severe mitigation is needed to stay even at 2C (1.5 C is almost impossible). And the world has decided not to do anything for another year. If you ignore a problem long enough, it goes away becomes unsolvable.

    • Side note. We have not reached anything close to what can be called a grand minimum.

  24. Pardon me for coming in a bit late in the game here, so to speak.

    First off, condolences to those directly affected by the tragedy on Whakaari/White Island.

    About the Māori name, Whakaari, the name itself means “making visible”, or something to that effect. Presumably that might be due to the heavy fumarolic activity of the volcano itself being visible from a long way away? Quite possibly, White Island could have been as frequently active as far back to the time when the first of the Māori arrived in NZ during the 14 Century CE.

    Also, in Te Reo Māori, the “wh” in most, if not all, Māori words and place names is pronounced like an “f” and not “wh” as in “why”. This is IIRC. At least Māori names don’t appear fiendishly difficult to say compared to Icelandic – remember Lady E? But I’ve seen some rather long Māori place names, though

    I’m only stating the facts from what I remember. Any Kiwis here may feel free to refute or correct what I said (keep in mind I’m Canadian).

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