Turkana and the Dawn of Man

/ 11/10/2016
The Lake viewed from The Barrier Volcanic Complex out over Teleki Volcano onwards to Lake Turkana.

The Lake viewed from The Barrier Volcanic Complex out over Teleki Volcano onwards to Lake Turkana.

I readily admit to enjoying large scale volcanism. Yes, small scale volcanism like Tor Zawar may be a fun diversion, but it is the majestic scale that volcanism can take that get my juices flowing.  By now I have touched upon most of the worlds large volcanic features at least in the passing, but there are still quite a few I have not touched upon yet.

Lake Turkana is one of those that I have pondered upon writing about for a long time. And there are two reasons for my interest, one is that it is caused by the largest mantleplume on earth and the second one is the effect that the volcanism has had on humanity during the Dawn of Man.

I would also like to point out that Lake Turkana is one of the most beautiful places I have had the honor of visiting. Going there is in so many ways to finally come home to where it all started.

Geological setting in brief

Lake Turkana from Space. Note the lovely Turquoise Water in the desert.

Lake Turkana from Space. Note the lovely Turquoise Water in the desert.

Most who are interested in volcanoes have read about the Great African Rift system that stretches from North of Afar down into Kenya where it divides into the East and West African Rift systems.

Lake Turkana is situated on the East African Rift and as with all parts of the Great African Rift system it is oldest to the North and youngest to the South. As such the volcanism will slowly continue to move southwards with time.

As the effects of the African super plume moved southwards a process of continental splitting started and it is this secondary effect that causes the continuing development of Lake Turkana. Technically the Lake Turkana volcanism is both spread-center volcanism and mantleplume volcanism; this explains the large volumes that occasionally are involved. Especially one eruptive sequence has been very large, The Turkana-Omo Basin eruption that lasted from 4.18 to 3.99 million years ago.

The Turkana Basin that holds Lake Turkana is a Graben of unusual size. At the northern end it is 320 kilometers wide and at the southern end it is 170 kilometers wide evidencing that the spread is continuous from north to south and that we may expect it to continue both in extension and in distance.

The original bedrock is dated to around 510 to 522 million years old. What is interesting here is that we can date the onset of spreading very exactly, it started with the Nabwal Hills eruption 34.8 million years ago in the northern end. That gives a very precise rate of the spreading at 0.92 centimeters per year. The rate of spread is higher as you get towards the northern parts of the Turkana depression compared to the southern.

The Dawn of Man

Turkana_Boy

The Turkana Boy with his large evolved skull and how the skeleton is well adapted for walking straight.

It may not come as a surprise that it is not until after the great Turkana-Omo eruption that what would in the end become Homo sapiens moved into the budding valley. And back then it apparently was as close to the Garden of Eve as is possible as evidenced by the large amount of hominid skeletons that have been found there.

During the next 4 million years the area was lush and it was open enough to induce developments and refinements to our upright gait. It is here that the our ancestors truly became bipedal, so much so that Homo ergaster was better constructed at walking upright than we are.

It is also here that we developed proto-speech and the Broccas Center in our brains. One theory is that close-living groups of more arboreal hominids did not need to convey messages over distance, but that it was a good thing out on a lush grass savanna where people was modestly separated from each other during hunting and gathering. It is also here that the human brain became larger in volume and we learned to control our opposable thumbs enough to manufacture complexly manufactured tools like stone-axes and stone knives.

It is here that the most famous skeleton of all was found by Kamoya Kimou while working for the Leakey’s. I am of course talking about the 1.6 million year old skeleton of the Turkana Boy. But, there is also a pretty much unbroken record of various hominids ranging for all of the 4 million years that the place has been inhabited.

I have so far mentioned that the area was a lush and green garden of Eve, this did though take a dramatic and tragic turn 10 000 years ago. At this time the Lake Turkana was at its peak, 3 or more rivers flowed in to the area and a great river flowed out of the lake, it was also the most densely populated place on earth. Then utter and almost total catastrophe struck.

It was though not volcanism that killed all the people, instead volcanism had made the ground some of the most fertile on earth concentrating humanity there. No, it was the end of the ice age causing a massive change in climate. The amount of rain in the catchment area diminished and the level of the lake fell more than 75 meters cutting off completely the outflow from the lake. And since the lake is volcanic with numerous fumaroles the water rapidly became saline.

And it is here that humanity turned from being a whimsical and slightly comic side-note in the order of things. It is at that exact moment we invented organized warfare. As harvests failed and the animals to hunt died off the humans banded together to kill each other over ever scarcer sources of food until a very small number remained, all of which is evidenced by numerous skeletons bearing signs of being killed in a very short time span. It is a sobering thought that the first known war was caused by scarcity and lack of water and food instead of the search of power and wealth. It is mainly sobering because at the beginning of the history of war we also see the likely end to the history of war, since we are likely to sooner or later start a great war for food and water. Know your history to know your future.

Today the area is populated even though the lake has lost its former glory. Today it is the world’s fourth largest saline lake and the area is dreadfully inhospitable. But, nature is resilient and fish and crustaceans have rapidly evolved from fresh water varieties into saltwater varieties that are surprisingly abundant. The area is very hot and highly arid and it is classified as a desert.

Volcanism at present Lake Turkana

North Island

North Island with it’s 3 lava flows. From this angle the third and youngest lava flow is partially on top of the next youngest and you have the older of the 3 to the right.

Thanks to the Leakey’s the area is surprisingly well investigated from a volcanological standpoint. In some instances it is even at apex of research. I will write below about the 4 currently active volcanic centers at Lake Turkana, most of them are single volcanoes, but in the southern end we find a real candy. Remember that the volcanism is spreading from north to south, so it is not surprising that the fireworks are down south. To the north there are several long dormant or dead volcanoes, but the first active volcano is to be found slightly to the north of the lake center.

Welcome to North Island situated at the northern central end of Lake Turkana. It is constructed mainly out of tuffs ejected from a series of tuff cones constructed out of trachyandesite. On the island there are 3 young lava flows of undetermined Holocene age. Two of them are likely to have been erupted at the same time, one from the dominant tuff cone on the island and the other from a flank vent of the cone. There is also a younger lobate lava flow extending to the coast of the island. We know that these are young since they have not been covered by sand from the frequent sandstorms, but we do see a marked difference between the two slightly older flows and the most recent that is still jet black. The lava flows are made out of basalts.

The island is still active with fumarolic activity to the north and southwest and there is no reason to exclude future eruptions.

Central Island with its many craters and Maars.

Central Island with its many craters and Maars.

The English are if nothing else highly consequent with their naming practices so our next stop is Central Island. Well, at least almost constant. The island is also aptly known as Crocodile Island from the abundant Saltwater Nile Crocodiles that galumph around oblivious to the fact that they should be freshwater crocodiles and that since their species is so old they should not be able to become a subspecies in such a short time. Well, just to confound everyone they did it, and here is probably a clue to how crocodiles survived the test of time, rapid adaptability.

Central Island is mostly explosive during eruptions, and there is evidence that the island is affected by water/magma interaction. The island is littered with explosive craters and the largest crater is larger than 1 kilometer across.

The island is a smorgasbord of varying lavas ranging from basic basalt all the way up trachydacite. That does not matter here, if it comes up it will do so explosively due to the magma/water and lava/water interaction.

The island has erupted many times during the Holocene, but no eruption has directly been witnessed in historical times. In the thirties the island was very actively producing steam and sulphurous gases and in 1974 it did a version of Kawah Ijen as it erupted molten sulphur.

The largest risk at Central Island is a medium sized explosive eruption, or that yet another kilometer wide Maar will detonate into existence. Not a happy prospect for the shore-dwelling local fishermen.

Lake Turkana from Southern Island.

Lake Turkana from Southern Island.

As we reach the Southern Island (Hohnel Island) the morphology of the volcanism has changed dramatically into an 11km long fissure volcano that is rife with young lava flows that has effused along the entire length of the fissure.

The lavas here are mainly unevolved basalt, but with some highly evolved inclusions or explosively erupted magmas such as phono-tephrite/tephra-phonolite and trachyandesite. It is most likely a sign that even here the volcanism has started to evolve away from basic basalt riftvolcanism towards a more explosive existence like its northern brethren.

The last dated eruption occurred in 1888 and it was a rifting fissure eruption quite like what we can see in Iceland. With that we leave the islands and get ready for some volcanic candy.

The Barrier Volcanic Complex

The Barrier with Telika Volcano in the forefront.

The Barrier with Telika Volcano in the forefront.

The ancestral Barrier Volcano is a large basalt shield that is heavily eroded. This ancestral volcano suffered a subsidence caldera formation in a large eruption 92 000 years ago. It is unclear if the northern flank of the volcano suffered a fatal collapse into Lake Turkana at this point or if this happened later. The summit caldera is circular with a distinct horseshoe opening towards the lake and it is 3.8 kilometers across.

Volcanism in The Barrier volcano has continued up until recently infilling most of the caldera floor and causing larger lava flows that has reached all the way down to Lake Turkana. The Barrier has had intra caldera eruptions during the Holocene, and some eruptions may have occurred within the last 2000 years.

What makes The Barrier into a real volcanologic gem is that it turned itself into a Somma volcano of sorts with distal flank volcanoes, something that is not common for large shield volcanoes and that may indicate that in the future a second larger caldera may form. It is though good to remember that this is not a true somma volcano, instead it is a basaltic shield caldera with both distal and radial fissures. In some ways it may be more correct to look towards a volcanic complex such as Grimsvötn for comparison instead of the classic image of somma-volcanism.

Now let us turn our eyes to the other volcanoes in the complex since they have stood for most the action in the last couple of thousand years.

After the 7710 Abili Agituk eruption from The Barriers northern part of the caldera and the southern flanks a range of subsidiary volcanoes has erupted on the distal and radial fissures.

On the northern side The Teleki Volcano grew down at the edge of Lake Turkana forming both monogenetic and polygenetic cones and vents. As Teleki erupted it created new land extending out into Lake Turkana causing the eruptions to be more explosive than the effusive volcanism you otherwise find at The Barrier. The last known eruption from Teleki occurred in 1921 and as such it was the latest eruption at The Barrier Volcanic Complex.

Next to Teleki we find Likaiu with one known eruption in the Holocene. It is a polygenetic cone of tephra and it last erupted in 1897.

Kenya, Lake Turkana, Andrews Volcano. Andrews Volcano is situated on The Barrier - a large volcanic uplift that separates Lake Turkana from the Suguta Valley (visible in the distance of this picture) to its south.

Kenya, Lake Turkana, Andrews Volcano. Andrews Volcano is situated on The Barrier – a large volcanic uplift that separates Lake Turkana from the Suguta Valley (visible in the distance of this picture) to its south.

One of the most active volcanoes around The Barrier is Andrew’s Volcano (also known as Nagaramasainia). It is a mainly basaltic volcano prone to suffer both from top vent and flank vent eruptions. Its last confirmed eruption occurred in 1917.

Volcanism at The Barrier Volcanic Complex may be cyclical in nature, but one must realize that the eruptive record is too short to ascertain that with any high degree of certainty. The first known eruptive cycle occurred around 1030AD to 1070AD and the next round of eruptions occurred between 1871 and 1921. This would spuriously put the cyclical rate to 800 years or so.

It is a bit problematic to talk about cycles at a place where you could easily loose an eruption or two. But, if we look towards Iceland where we also have spreading center volcanism combined with mantleplume activity we also see distinct cyclical patterns emerging there, so it would after all not be farfetched to believe that the same could be happening at Lake Turkana and The Barrier.

Turkana, volcanism and dating

In volcanology we tend to look towards ice cores for everything, but there is another very good way to date things and that is from lake sediments.

For a long time it was believed that the VEI-8 eruption of Toba almost wiped out humanity. The first “evidence” of this was that the ash should have produced a long term and extensive climate change due to ash hanging around in the upper atmosphere. The second evidence turned almost ludicrous as they took the inbred genome of Europeans and determined that very few people (around 25) had survived on all of earth.

For some reason they forgot to mention the vast genome variations that exist in Africa. After all, it was not a million man strong exodus that meandered out of Africa to colonize the planet, it was just a couple of hundred and they most likely came from the same tribe. So, the genome was limited to begin with.

The sediments of the Dawn of Man.

The sediments of the Dawn of Man.

That wandering band of humans had reached quite near Toba as it blasted off about 71 000 years ago (Lake Malawi sediment core), so the toll on them was quite naturally high. That notwithstanding there is evidence that they survived the ordeal surprisingly well as evidenced in the archaeological records directly on top of the Toba ash in Southeast Asia.

Now I hear people who are not readers of Volcanocafé start mumbling: “Hey, it was a supereruption, all that ash must have killed everyone! The Daily Fail says so!” Not really, first of all we must realize that 90 percent of the ash will come out as pyroclastic basesurges that will inundate everything within a circle of 100 to 250 kilometers. This is an absolute death zone. Nothing will survive here. Another 9 percent will fall down as distal ashes and only 1 percent will be injected so far up into the atmosphere that it will linger. Question is how long will it linger? This amount will halve every 3 months, so within a year the effect will be pretty much gone.

Aren’t volcanoes gassy? Yes they are, but the same goes for the sulphates that the volcano produces, so after about two years even the largest eruptions have had their sulphates washed out sufficiently to not be a problem.

Now you are probably wondering why I am yabbering about Lake Toba when I am writing about Lake Turkana?

There are two reasons for this. One is that the place has been inundated by paleontologists looking for skeletons for the last 50 years, so we have a very good skeleton-history of Lake Turkana vis-à-vis human mass extinctions. And one thing that is abundantly clear is that there was no mass dying there during the Toba eruption. As many skeletons was produced before as there was after, thus proving that the procreating humans needed for the skeleton production had not died out or gone through an existential “eye of the needle” moment.

The other reason is of course that Lake Turkana (and Lake Malawi) is filled with wonderful deep undisturbed lake sediments. So, scientists took core samples and looked for all that doomsday ash that supposedly should be there. Obviously they did find Toba ash, but the amount is more indicative of a temporary cooling for a year or two and not widespread famine. Today the volcanic winter theory is rather soundly disproven and the previous given figures of 3.5 to 4 degrees Celsius temperature drop has now been moderated to around 2C for around two years time.

So, what then happened to all that Toba Ash? Well, Toba is on an island so all the ash ended up unceremoniously out in the Southeast Asian sea. Both the pyroclastic base surges and the distal ash. The latter was evidently blown out by the monsoon into the sea where.

Conclusion

The view from The Barrier over Likaiu and Telika. Out in the water is Southern Island. Photograph by Michel Laplace-Toulose.

The view from The Barrier over Likaiu and Telika. Out in the water is Southern Island. Photograph by Michel Laplace-Toulose.

Grand scale volcanism and geology does not always need to come attached with the prefix of super- to be interesting. Few places have such a rich coexistence between humans and volcanoes as Lake Turkana. In many ways all of us have this remote spot on earth to thank for us becoming us. It is here we developed the ability to walk straight, talk less straight and beat ourselves to death. It is a microcosm of human prehistory in the shadow of the volcanoes that formed humanity.

CARL REHNBERG

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107 thoughts on “Turkana and the Dawn of Man”

  1. Great article Carl.

    On the subject of large scale volcanism, I’ve noticed in the past that the rift lakes nearby and north of Turkana that (perhaps slightly older) have some seriously big caldera systems. As is often the case, these caldera systems exhibit even more evolved magmatism than what we see at Turkana, with Rhyolite, Obsidian, and other evolved magmas featuring prominently in some of these areas along with known ignimbrite deposits.

    Of particular note are the O’a Caldera (15 x 25 ) and the Awasa Caldera (30×40), which put them well into the possible VEI-7+ range in terms of size. These are two of the largest, but there are many more calderas that are similar in size to some of the biggest eruptors we’ve seen in the holocene (8×12) both south and north of Turkana. We know there are associated ignimbrites with these as well. Unfortunately, research and papers on such volcanoes are few and far between, and much less accessible than more well-known volcanoes around the world.

    Suffice it to say, the rift valley of Africa has seen some seriously prolific volcanism, especially when you combine this with the even more voluminous basaltic shields that dot the rift valley regions. But in historical times, we really haven’t seen anything all that notable. Sure, there is Erta Ale and a a few others that have been active, but given the pure scale of volcanism here, it seems that the activity as a whole has been in a good bit of a lull.

    Would it be somewhat accurate to question if the rift valley has been in a sort of volcanic down-period over the last 10,000 or so years compared to its previous activity? I know rift-related systems will vary their activity greatly depending on rift cycles, so if the rifting were greatly reduced right now, that would obviously explain the lower level of activity seen.

    Final question, do you think the Turkana system could possibly evolve into more of a large eruptor as it ages and shifts into more evolved eruption styles?

    On another note, just an observation, but the Marsabit shield volcano is full on ridiculous in its size. The mountain it has created on its very own above its rift system is over 140km long. It must easily be one of the largest shield volcanoes in the world that is not formed on an oceanic basin.

    • I agree fully that the rift valley systems have been very quiet in the last 10 000 years compared to what it can do when it is in hyperdrive.
      It seems that as the rift propagates onwards it produces prodigious scale volcanism with comparable to a medium sized trappformation. And as that calms down we see the more explosive eruptions producing calderas of all sorts of sizes.
      So, to see a large basaltic eruption we would have to expect it down to the south of Turkana. It is though good to remember that the Kenya Dome Plume has entered in under the Tanzanian Craton and that will hamper things for a while.
      I would though not rule out a mid-craton large explosive eruption if the plume succeeds in puncturing the craton.

      Back to your question about Turkana itself. I expect the volcanic islands to dwindle over time with the possibility of new islands forming over time. The real action will most likely be at the Barrier that seems quite intent to become a plume driven large volcanic system that will evolve over time into ever more explosive eruptions. It is a very funny and unusual system for Africa.

      • Very informative, thank you. The aquatic ape theory, popularised by Elaine Morgan would seem perhaps to have its basis here, in this fertile, and watery Eden of long ago. The slowing of the rifting might, I suspect, be linked to the slowing collision of India with Asia, which I have always visualised as being the connected to the African Rift Valley, since India launched itself off the coast from the north of Madagascar however long ago that was.

        • Well, I stayed away from diverse more off the track theories here. The part about the Dawn of Man is mainstream paleoarchaeology 101.
          The rifting is ongoing and does not seem to slow down, at least from a plate tectonic point of view. East Africa is happily meandering ESE at a steady pace.

          • Love that there is stuff being written about Africa. I feel like there is so much to be learned from the rift valley, but we’re only scratching the surface, and so much is still just speculation right now.

          • I think that to get more of the picture we would need to scratch under the surface in other places. Because we do not really know where the hominids came from prior to the Rift Valley period, at least not well.

          • I was more referencing volcanism in general there. Maybe I should have just stated I wish I knew more about the superplume, what it has affected, how it will further develop / affect Africa, and other related items there.

            Has the plume cooled down a bit? I know that the rifting has slowed significantly, which is why we do not currently see flood basalts there – what affects the rate of spreading here? Has the spreading slowed down due to collision with Eurasia? Also, what should we make of the massive body of magma beneath the rift? Why are the rift lakes on the western side of the rift extremely deep, while the rift lakes on the eastern edge significantly more shallow? If the rift is forming in a zipper-like fashion from north to south, then why is there old volcanism and rifting as far south as lake Malawi? How does the splitting off of Madagascar factor in to all of this, was there a separate plume that popped up when that occurred that tore it off?

            Just so many questions I’m curious about, many which I don’t think we’ll know a definitive answer on for a while.

          • I think there seems to be a misconception.
            If we take the current rate of spread and backtrack it over time we see that the rate of spread is consistent with the amount that the rift system has stretched. So, there has been no slowing down of the spreading.

            We do know a few things about the plume, one of those is the general shape and size due to tomography. And here we get a clue as to why there are few or no large eruptions today. And that is due to the center of the plume being hindered by the Tanzanian Craton.

            That being said, you are correct. This area of the world needs a lot more studies, otherwise it may give us a very nasty surprise in the not so distant future.

        • I’m kicking myself for not saving the paper, but a while back I read something that mentioned that the reason we do not see flood basalts from the African rift currently (as we have in the past) is that the spread rate is not high enough.

          In the majority of continental break-up events, we know there are at least certain elements of flood basalt volcanism. We saw it in Afar when arabia split off, we see it in Parana/Etendaka when south america split, and there are many other examples.

          Currently, there is somewhat of a big rift in the middle of Siberia at lake Baikal, but this is an extremely slow-spreading rift. I was curious as to why there wasn’t much volcanism at such a big rift lake as there is in Africa, and it was implied that it was a product of the extremely slow spread rate.

          Given that we haven’t seen flood basalt volcanism from Africa in geologically recent times, this seemed to imply that the spread rate isn’t quite fast enough to induce the level of decompression melt required for flood basalt volcanism.

          • I have read papers stating the same.
            But, when you really do the math yourself you will find that the numbers does not add up. Or, perhaps more succinctly, they add up perfectly.
            If you take the current spread rate and a well known figure of spread and do the division you end up with it being exactly correct.

            No, the answer is to be found in three other factors than spread rates jumping up and down.
            1. The Kenyan Dome Plume is now a good way in under the Tanzanian Craton where it is producing weird things like the Ngorongoro super-eruption (and a fair few other smaller calderas) and Ol’Doynio Llengai.
            2. Large basalt floods are far in between over the time of the creation of the Great African Rift System. The Turkana-Omo is 4 million years ago for instance.
            3. It is when the plume has domed up the continent sufficiently for a new rift to form you have the excess magma pooled to create the large flood basalts. Logically rapid spread does not affect this, it is the pressure from below.

            I do not see this huge lack of large eruptions, I just see that we are living in an interlude that may be paper thin. For all we know due to lack of research there may be domings ready to burst or large magma pools in the continental crusts ready to do rather nasty things, and here we do not know if it is going to happen until it happens.

            I will return to this soon since I am feeling a rather large african urge at the moment 🙂

    • Great post – and good points in this comment; in a new paper (open access, so all should be able to read it), we present some new age dating work for some of the caldera forming eruptions of the main Ethiopian Rift. This does suggests that episodes of large explosive eruptions are pulsed, and that rates of Ethiopian Rift volcanism are rather lower now than they would been during the last ‘magmatic flare up’ 250 kyr ago.

      http://www.nature.com/articles/ncomms13192

      Quarantined by our anti-spam robot aksimet (happens to all new submitters, and sometimes to old ones), probably on suspicion of being too accurate to be trusted. Aksimet has been overruled – Admin

      • Thank you David!

        And I must admit to being a fan of your seminal paper on the Ethiopian Rift!
        I had planned to write about your paper in a later article when I have finished meandering about in the current rift.

      • Thanks for the response David, and thanks for the open-access paper!

    • I must say that the really intriguing thing here is why they are putting in an array at Bear Island with a whopping nine seismometers. It is out in nowhereland from a geologically interesting standpoint. Something tells me that it is more related to finding oil than monitoring earthquakes and volcanoes.

      I hope they emplace 3 more seismometers (to get a full five) and 5 GPS stations at Jan Mayen with a reference station at Greenland. That would be awesome, especially if they put them online via Nordvulc or FutureVulc.

      • You might be right with the oil ;o) but let’s hope for more publicly available data. And at least Bear Island would be an additional point for better positioning of quakes on the Atlantic Ridge…

    • It is both saddening and liberating to know that we were stupid from get go. It was just the means and the reasons that lacked us. It speaks badly for our future.

      • Sort of melds with the Homo Stultus idea. Personally, I’m a hardcore believer in the abject stupidity of mankind. And don’t forget, current thinking is that Lucy fell out of the tree.

        Similar thing happened to my room-mate back in “A” school when base security discovered him in an amorous adventure with a date in a stand of trees near a secure compound. Broke his arm and ended his date. Lucy set the precedence. It’s not the fall that’s dangerous, it’s the sudden stop at the end.

        Falling is easy. Surviving is the hard part.

  4. Activity at HUS. Doesn’t look like weather, as no other stations indicate wind.

  5. Curious and utterly irrelevant information dept: Teleki is likely the only volcano in the world named for a Hungarian Count.

    • I did not know that. But it is not that surprising, a lot of white dudes explored in that area and “discovered” Africa.

      When I stomped about in Kenya I had a curious feeling that it felt like coming home more than anything else. It is not until you sit under the starlit sky in Ngorongoro you really get the picture, that we are all Africans, estranged like me or currently living in Africa Africans.
      It was a curious sensation for a deep frozen middle aged decidedly white Swede to metamorphose to a homecoming African, it changed me forever.

      • Here is another swede having the same sensation of “coming home” when in Africa… Thanks for very exciting post!
        Yes all of us came from there. The Turcana region was not only one paradise but many, providing many different ekological environments for the evolving super specializing non specialist homonids to explore. An ideal evolution laboratory. And for sure, they were fighting each others already from the first day. Also our closest relatives, the chimps are engaging in what can be liked with war expeditions towards their neighbors. For competition or pure excitement, is unclear. The homo stultus genes were there already with our chimp common ancestor on good and bad…..

      • It must be genetic. Wherever we go, if we have enough resources we create parks and lawns — expanses of grass dotted with widely-separated trees. Terraforming the area to look like the damn Serengeti.

        • I never thought about it like that, but there may be a point to it. And wherever we live, we prefer a good open view.

  6. Hi! i just discovered your excellent page. I also like volcanoes since I’m from Chile with a loot of them 😀
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    /Admin
    Sorry that you got stuck in the spamfilter.

    • Hi Aficientifico, Welcome! Thank you for sharing your blog. Giggle translate isn’t at its best but it looks interesting. Hope you enjoy the conversation 🙂

  7. Excellent Post, Carl- the Great Rift valley has always intrigued me…

  8. Very nice post Carl! It is a fascinating area where people have developed amidst the evolving climate, albeit not the only such place in Africa. And yes, going to the Africa savannah feels like coming home. The Toba impact was perhaps a little larger than you list, but not the global extinction event some papers make it out to be. Parts of southeast Asia and of India were devastated, but recolonized by the same cultures so clearly some survived even in these areas. Still, a 2 degree cooling is enormous and would very badly affect farming, but hunters would get through this better. One study linked Toba to the onset of deep cooling in the ice age but this relation seemed unlikely.

    • Toba was a gigantic eruption by any way of counting it 🙂
      My point was merely that the bulk of humanity was not that heavily affected since they had the good sense to not live A) where it happened, and B) in a climate were a 2 degree drop is just making the heat slightly less.

      I will soon return to other nice spots in Africa with a deep hominid history near volcanoes.

      • Don’t forget the footprints. They are a perfect example of a parent walking the kids to safer ground.

  9. Just now noticed new post.

    Wednesday
    12.10.2016 15:03:09 63.646 -19.325 0.1 km 2.4 99.0 3.8 km W of Goðabunga

    Also IMO has put out warnings:

    Warning- River levels will continue to rise in southern Iceland until midnight on Friday. Heavy rain also increases the likelihood of landslides.

    Warning- Heavy rain is expected in south and west Iceland today and in the south part of Iceland tomorrow. Strong gale (more than 20 m/s) is expected in the west part and in the highlands with strong windgusts by mountains until late night.

    Please excuse if someone else has mentioned this. Now off to read the new post. 🙂

  10. Hi Carl and Albert, Your last two posts have timed amazingly well with my current TV documentary viewing and have caused a distinct increase to the frequency of unsociable ruminations concerning the topics of ancient continents and human origins at work. Thank you for the welcome distraction! 🙂

  11. Carl and the team these posts just keep getting better and better. Cbus asked a few questions that I was going to ask as well. This area needs to be more studied as we are seeing a continent break apart right in front of our very own eyes. A small question what happens to a plume when it comes in contact with a craton ?

    • Lurking is quite correct.
      I hope to get around to the kimberlite eruptions in a while. I got so enamoured with writing about African volcanism that I am going to do a few more.

    • If the plume is close to the edge of the carton, it could go round the side? Create a rift?

      • Depends on the amount of energy involved. It’s a time contest. If it’s hot enough to cut through the rock or if boyancy gets the path around the edge established first.

        Then there is the matter of pooling under an irregularity of the bottom structure… and I’m pretty sure underplating would also play a role. A moho map of Iceland illustrates the pooling issue well. It’s funky down there

  12. All,
    If somebody that has more experience with watching Mauna Loa, please look at the last 14 days of earthquakes on the island. I have noticed that we are getting more of the 1.8 to 3+ quakes (the sizes the HVO compares with the past history of eruptions since the old meters could not discern earthquakes below a 1.8 in the prior eruptions) all over the island (and in the waters surrounding the island). Most of these are not under the caldera but all over the island. I also noticed that the cross caldera distance on Mauna Loa has made a short term almost exponential increase compared to the increase from the low in March 2016 to late August. I also noticed a small swarm of small earth quakes and at shallow depth (with some of the webicorders mitd and ahud possibly showing a little lava flowing????) from the Kilauea caldera moving south and west possibly showing a new path for a breakout?

    I am a rookie, only starting watching this area since I started planning our trip out there this summer.

    Be gentle
    Mac

    • Kilauea: there is a rift that runs southwest and this has been a bit more active (earthquakes) recently. That may be due to some slow slip of the south side of the mountain (that happens regularly). It does not indicate an eruption there but it is a line of weakness which in the past has erupted.

      Mauna Loa has an accumulating magma reservoir, relatively shallow. This is causing the episodic lengthening of the caldera (there was another jump in the past week) but it is not centred under the caldera (little inflation there). An eruption in the next decade is getting more likely.

      The earthquakes all over the island tend to be deep, and are related to gravitational settling: the whole island is sinking a bit (to compensate the magma coming up) and this gives some deep quakes.

  13. In Minnesota, pig wrestling is a misdemeanor. (According to Wikipedia)

    • It is probably due to all the crazy Swedes that went there. After a few (many) strong ones they probably remembered that Särimner (The Asa Pig in Heaven) becomes more tender if wrestled daily.

      • Had to inoculate a pair of Yorkshires once in the pen, in the
        mud and manure. I slipped. these were little piggies. They
        both though I wanted to play. I ended up being sat on and
        roughed up (playfully of course..)
        Watching -my Pop was hysterical laughing so hard his stetson fell off-in the pen. Now my turn to laugh….
        Miss that..

        • Not even I can come up with an idea for that one… Definitely not a Swedish thing 🙂

        • At least on this point Minnesota and physics are in agreement.

          They should consider adopting a law against repulsive gravity. After that they could move on to clearing up some of the more controversial areas of particle physics and string theory.

          • Now I’ve got Smoke on the water by Deep Purple on my mind. Only sing

            Smoke under water, don’t listen to the sign… 😆

          • Yeah, that is the question. Rules and such don’t come about unless someone has an issue with the subject. The law making it illegal to turn an 8 mule team wagon around on State Street in Jackson MS was because it tied up traffic of the time.

  14. Two quick irrelevantis things.

    1- When was the last time the sun shone on Katla? Poor volcano. Probably depressed.
    2- Where is all my icebergs go from jokulsarlon? The ‘river’ is almost clear. Is this normal fall behaviour?

    • The answer to number two is that Sean Connery needed new icecubes for his whiskey.

  15. And on a highly esoteric note of humor.
    What is the best way to make Ed Fredkin disappear?
    Supposition: The world is discrete and is a program running on a universal computer that is the Universe.
    run:@/0 (this is a mathematical operation written in its simplest computer form)

    I may be the only person on the planet who finds this hilarious.

      • I know but to well how Fredkin would interpret that sentence.
        But in this case @ is the universal zero, a perfect mathematical black hole and if you divide that by zero you get the end of all operations.
        On the other hand he would probably dish out some funky russian math only he knows and prove that it would make him into the Universe.
        So, knowing all to well how futile it is to argue with Fredkin my vote is on the omni-present now that you mention it. Darn 🙂

        • So, if @ is the universal zero, and you divide it by zero, the answer is one?

          • Well, 42 is the ascii for *, and at the time the book was written, * was the “match everything” character in Dos, CPM, and ‘nix operating systems… computers in general. Deep Thought was,a computer, so, when you look at it like that, the answer is no longer non sensical. The ultimate answer to the universe really is “everything”.

    • /dev/null is not the correct directory to move your files.

      • I have another way to get zero (or to get fired)
        cd /www/
        rm -rf *

        🙂

        Otherwise volcanoes are too quiet

        have a nice week-eend everybody

        • And here you see * used in the proper context… as a wildcard that matches every name. Kiss the contents of that Web root directory goodbye. That Apache daemon won’t have anything to play with at all.

          Personal Opinion: Best webserver software ever built.

  16. On a brief side note: Halemaumau lava lake is very close to overflowing; just a few feet.

    It wouldn’t surprise me if it actually does flow at the peak of the next D/I cycle. Cams:

    • Wonder what grows in that old ladies garden? Since the regular tests didn’t seem to find anything it is probably some unusual plant or fungus.

      My bet would be some sort of fungal thing. The symptoms reminds me of what happened to a friend while we were down in an old mineshaft and he stuck his hand into a fungal growth. He saw interesting things after a couple of minutes.

      • Might even know those Deputies, or EMT’S. Coos county has an abundance of hallucinogenic mushrooms there , I worked with the local Narcotics Enforcement people when I was a Real Estate broker and on the Realtor’s board there.
        We were out in the community and were to report anything
        if we could. Place was and still is awash in Meth activity.
        Down the coat in the Bandon area, there was this “Organic
        Bakery” (Honestly the owner was this wifty-drifty new agey
        woman who was, for the most part harmless,.) . They
        made a pizza with “Local Mushrooms”. Similar results
        to the above Coos Bay indecent…
        Except one Pizza was served at a local Church Bazaar.

    • Good one! So with regards to volcanoes and beach balls… if there is an EQ swarm could we tell if the events are related to regular tectonic slips (all aligned to the fault) or magma movement (not aligned)?

      • Magma intrusion or dike propagation would tend to show as a series of “mode one” fractures. They would show up as normal mode faulting with varying orientations, dependent on whatever dominant fault plane there was.

  19. And with a bit of luck the lava lake at Kilauea will be over flowing in a few hours. A rare event indeed if it happens.

    • And as I wrote that the lava lake of Kilauea started to deflate.

      • It is quite a tease.
        A month ago it was nearly this high as well and I recall trying to predict the moment of overflowing last year too with little result.

        Though looking at the picture now, it does seem it overflowed the rim a bit on the right.

  20. And since nothing interesting seems to be happening anywhere I am taking comfort from this earthquake in Iceland.

    Saturday 15.10.2016 01:49:47 63.580 -19.423 32.9 km 2.3 99.0 6.6 km NNE of Skógar

    A brief explanation here, the largest seismic unrest episode in Iceland was at Godabunga. It is a proto-volcano intrusion occurring near Katla, but that has it’s own feeder system and that formed a magma reservoir independent of those at Katla.
    The earthquake that perks my interest here is at the MOHO boundary were the feeder system into Godabunga starts. It is also unusually powerful for that depth.
    It may indicate that new magma is about to start coming up into this feeder system, if so Iceland will become noisy in the months to come.

    • Another deep, larger than usual for the depth, near Askja. Not quite as deep, but still interesting.
      Sunday
      16.10.2016 00:05:19 65.064 -16.736 19.4 km 2.3 99.0 6.8 km WNW of Dreki

  21. Slant feeder, could be Katla –> Eldgjá.
    None matches Godabunga actually, except it be fed from east, not north-west..
    Caution, not all faults are vertical.

    • I know it’s screwy. I have found if I keep messing around on it it does finally show them. However I haven’t the slightest idea how I trigger it into showing them yet. If anyone know whether or not it’s went to a different page. I’d like to know too.

    • Same for me… Could be Google who’s to blame, in a similar maps page I got at least “some features failed to load”.

  24. There was a small EQ swarm in the north-east corner of Hofsjokull including some quite deep ones (7km) yesterday.

  25. I was asked a question to which I did not know the answer. What is the smallest country on earth that has a volcano? I assume meant was an active or dormant volcano, not one long extinct. And ‘smallest’ is probably meant as surface area rather than population. (And certainly does not mean ‘significance’ which gives too much freedom to personal preference.) Does anyone know?

  26. There will be a new article in a day or two.
    I just finished writing an article, but I need a couple of hours for sourcing of images and editing before it is ready to go. With a little bit of luck I will be able to publish it tomorrow.

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