What happened at the end of the Eocene?

 

Southern margin of La Garita Caldera, Colorado, from USGS http://pubs.usgs.gov/imap/i2799/photos/8-S_LG_caldera_margin.html

Southern margin of La Garita Caldera, Colorado, from USGS
http://pubs.usgs.gov/imap/i2799/photos/8-S_LG_caldera_margin.html

I have a long standing interest in large discontinuous events in history – essentially things that go “boom” – and their impact on geology, living things, and the course of history – how these events happen, what makes them happen, and why they happen.  This interest has led me to volcanoes and their eruptions.  It has also led me to look into impact events that wipe out types of life and significantly rearrange the landscape.

A lot of the causes overlap in time or take place so far in the distant past that it is difficult to figure out which caused which.  We also need to remember that volcanic activity is for most intents and purposes continuous, though it does wax and wane in intensity over the millions of years as driven by plate movements, rifting, collisions and mantle plume / hot spot activity.

Fish Canyon Tuff – La Garita Caldera, Colorado

Fish Canyon Tuff – La Garita Caldera, Colorado

To me, the most important questions are what causes the discontinuity in climate?  What causes multiple extinction events?  What causes sufficiently large insults to the environment that lead to mass extinctions of entire species and significant long-lived change in climate?  Usually, the Flying Finger of Fate is pointed at a single cause which may be volcanic eruptions, impact events, close supernovae explosions, methane blooms, massive global heating, massive global cooling, aliens, etc.; none of which we have ever see in real time.

What I am wondering is that while volcanic eruptions place significant stress on the environment, cooling things down for years to decades or longer, perhaps they need something else happening at nearly the same time, something big to trigger an extinction event.  A few examples follow.

Graphic showing location of proposed Shiva impact structure.  Unable to find original paper.  Image was posted at link below: http://rajgire.wordpress.com/2012/03/13/shiva-crater/

Graphic showing extinction events, large igneous province outbreaks and massive climate shifts. From Large Igneous Provinces Commission, August 2013 LIP of the Month http://www.largeigneousprovinces.org/13aug

A Few Extinction Events

The Cretaceous – Tertiary boundary 65 million years ago marking the end of the dinosaurs is thought by some to be linked to the Deccan Traps in India.  There is a roaring argument about which caused which, as there are a pair of impact structures identified dating to around that time – the Chixculub crater in the Yucatan and Shiva off the west coast of India.  Regardless of the resolution of the argument, it appears both volcanism and impact events were involved.  http://news.nationalgeographic.com/news/2009/10/091016-asteroid-impact-india-dinosaurs.html

Graphic showing location of proposed Shiva impact structure.  Unable to find original paper.  Image was posted at link below: http://rajgire.wordpress.com/2012/03/13/shiva-crater/

Graphic showing location of proposed Shiva impact structure. Unable to find original paper.

The Permian – Triassic extinction event which wiped out over 90% of marine species and over 70% of all vertebrate life on dry land some 250 million years ago is another.  It is mostly blamed on the eruptions from the Siberian Traps that caused a massive rise in global temperatures.  Some have suggested an impact component with a couple candidate large crater structures suggested.  But if the Traps erupted over an extended period of time, several millions of years, as have been suggested here, then the impact events punctuate and immediately push an already stressed environment into failure.  Causation on this is even less well known, but volcanism is clearly involved.  Impact events may also be involved but several other mechanisms have been proposed like mass release of methane (greenhouse gas) into the atmosphere as the planet heated up.  http://www.space.com/2452-giant-crater-tied-worst-mass-extinction.html

There also seems to be an antipodal effect where volcanic activity or mantle hot spot is found on the other side of the globe from an impact structure that Geolurking wrote about last year or so.  Hot spots may end up being fossil evidence of impact events into the ocean.  http://www.mantleplumes.org/WebDocuments/Antip_hot.pdf

The gradualist geologic view of the world has changed over the last century, with grudging acceptance that large, relatively instantaneous catastrophic events have driven the history of life on this planet.  Not having seen one actually happen (and I don’t want to), we are left with the scientific method of comparing observations and theory against models while building them up and tearing them down.

Impact events, even relatively recent ones in the last few thousand years, are difficult to pin down unless they are really, really large.  70% of the surface of the planet is ocean bottom, crustal plates that have a finite lifetime and are either subducted into oblivion or crunched up into mountains when trapped between two impacting continents (Himalayas).  We can extrapolate the flux of inbound bodies based on the number of craters known on the continents, but this is at best a low estimate as it does not consider airburst events (Tunguska, Chelyabinsk) which apparently regularly take place.  And sometimes those airburst events get very, very big.

There is a group of people investigating the possibility that a comet storm caused a continental level extinction event over North America some 12,000 years ago – think tens of thousands of Tunguska sized airbursts raining down over North America in the course of a few hours – plunging global temperatures back to ice age levels for over a thousand years (Younger Dryas).  There has been no volcanic component yet proposed for the event outside a suggestions by a Mexican geologist that “trap-door” calderas in Mexico were responsible for the presence of ignimbrites in Mexico and the Southwest US.  An alternate view based in experience with what happens under nuclear fireballs believes the ignimbrites were formed by multiple airbursts and the melted, glazed rock is the remains of airburst created density currents.  http://cosmictusk.com/first-harvard-now-dartmouth-evidence-identified-for-younger-dryas-impact/

With this background in mind, I would like to explore for a bit the minor extinction event at the end of the Eocene, some 33 million years ago.  The event is marked by large impact craters, most notably one centered on the mouth of the Chesapeake Bay in North America, and an outburst of caldera activity in what is now Colorado.  It also marked a downward shift in global temperatures toward the ice ages we now endure.  This is in no way a comprehensive exploration, but more a way to publicly scratch my head.  Something clearly happened.  The question is what and how?

Calderas

Fish Canyon Tuff – From USGS Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado http://pubs.usgs.gov/imap/i2799/

Fish Canyon Tuff – From USGS Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado.

There was a caldera outbreak in Colorado some 40 – 25 million years ago.  This outbreak spanned the Eocene extinction event.  Whatever impact on climate due to the eruptions was exacerbated by impact events around the 33 million year point that were sufficient insult to change climate and wipe out species.

http://books.google.com/books?id=KLtUAAAAYAAJ&pg=RA1-PA93#v=onepage&q&f=false

Activity in the San Juan Volcanic Field started some 40 – 35 million years ago and for the first 5 million years was dominated by andesite, rhyolite and mafic quartz latities.  Height of the activity was some 35 – 30 million years ago, at the time of the Eocene event.  Around 30 million years ago, the activity shifted to a predominantly ash-rich, pyroclastic output which tailed off over the next several million years.

http://pubs.usgs.gov/imap/i2799/

There is a paper or two that suggests the caldera outbreak was related to a chunk of the subducted Farallon plate that either broke off or traveled parallel under the North American continent rather than diving into the mantle to melt.  As the continent stretched a little bit with the uplift of the Colorado Plateau and the failed Rio Grande rift, this allowed the melt to rise to the surface and eventually erupt.

http://www.colorado.edu/geolsci/Resources/WUSTectonics/CzIgnimbrite/ignimbrite_intro.html

Snowshoe Mountain (resurgent dome) within Creede Caldera, Colorado (image behind paywall) http://elements.geoscienceworld.org/cgi/content-nw/full/4/1/17/FIG4

Snowshoe Mountain (resurgent dome) within Creede Caldera, Colorado (image behind paywall)
http://elements.geoscienceworld.org/cgi/content-nw/full/4/1/17/FIG4

And erupt it did, climaxing in the eruption of the Fish Canyon Tuff out of the La Garita caldera some 28 million years ago.

This eruption deposited some 1,200 cubic miles (5,000 cubic kilometers) of ignimbrites across North America in the largest known single eruption in the last half billion years.

The San Juan Volcanic Field in southern Colorado contains up to 18 calderas and as many identified flow deposits and represents the center of this activity.

The La Garita caldera measures some 22 by 47 miles (35 by 75 kilometers) and was active for a couple million years after the Fish Canyon eruption.

Its output was prodigious.

http://gsabulletin.gsapubs.org/content/120/7-8/771.abstract

Map of San Juan Volcanic Field from Geological Society of America http://gsabulletin.gsapubs.org/content/120/7-8/771.abstract

Map of San Juan Volcanic Field from Geological Society of America
http://gsabulletin.gsapubs.org/content/120/7-8/771.abstract

A related volcanic field in central Colorado buried a stand of redwood trees west of Pike’s Peak near Florissant, Colorado.  The fossilized stumps have been partly excavated and can be seen Florissant Fossil Beds National Monument.  They date from around 35 million years ago.

http://www.nps.gov/flfo/index.htm

Fossilized redwood stump – Florissant Fossil Bed National Monument, Colorado.  Buried by volcanic eruption from 39-mile volcanic area, Colorado http://www.conifers.org/cu/Sequoia.php

Fossilized redwood stump – Florissant Fossil Bed National Monument, Colorado. Buried by volcanic eruption from 39-mile volcanic area, Colorado
http://www.conifers.org/cu/Sequoia.php

As the disconnected piece of the Farallon plate melted, it is thought to have provided a source of eruptible material in Nevada, Utah and Northern New Mexico until around some 19 million years ago when the source was depleted.

As large and as active as this area was, it does not formally comprise a Large Igneous Province (LIP).  Interestingly enough, during this time there was a LIP erupting in the Afar – Ethiopia region that was most active around 30 million years ago.

http://www.largeigneousprovinces.org/0events

Impact Events.

There are three large craters identified that date at around the 33 million year point when the climate changed.  One formed the mouth of Chesapeake Bay south of Washington DC.  The crater is 53 miles (85 kilometers) across and is thought to be formed by a body a mile or two (3 – 5 kilometers) in diameter.

http://pubs.usgs.gov/fs/fs49-98/

Map / drawing of Chesapeake Impact Crater – from US Impact Craters http://www.impactcraters.us/chesapeake_bay_virginia

Map / drawing of Chesapeake Impact Crater – from US Impact Craters
http://www.impactcraters.us/chesapeake_bay_virginia

A second impact crater has been identified about 200 miles (320 kilometers) northeast of this crater.  It is offshore New Jersey and called Toms Canyon.  It has also been dated around the same time as Chesapeake Bay.  Toms Canyon measures 9 – 12 miles (15 – 20 kilometers) across and was formed by a much smaller body.

http://www.sciencedirect.com/science/article/pii/S0025322797001138

The third large impact crater is Popigai in Siberia.  It dates around the same time as Chesapeake and Tom’s Canyon, but was formed by a larger body.  It measures some 62 miles (100 kilometers) across and was thought to be formed by a 3 – 5 mile (5 – 8 kilometer) diameter body.  This crater is little studied as the Soviets found shock-created diamonds at the site and used residents of the Gulag to set up mines for them.

http://www.passc.net/EarthImpactDatabase/popigai.html

Popigai Impact Crater, Russia (Siberia). From Elite Daily

Popigai Impact Crater, Russia (Siberia). From Elite Daily

There are numerous smaller impact craters measuring in the few miles to kilometers across that date sometime in the Eocene, and it appears that Earth was in the midst of a shower of inbound bodies for several million years.  Eventually the serial insults to the climate built up to the point where natural processes were unable to keep up and the climate changed.

http://en.wikipedia.org/wiki/Category:Eocene_impact_craters

Discussion and Conclusions

Where to go with all of this?  There are several observations to sort out and place into some sort of framework.

The first observation would be that massive volcanic eruptions appear to be insufficient to place the planet into a new Ice Age or by themselves cause an extinction event.  This is not to say that they don’t do enormous damage, kill a lot of plants, animals and people.  But an extinction event means you wipe out all members of a species worldwide.  Some actual study of reported global temperatures for the last century compared with volcanic eruptions by Willis Eschenbach over at “Watts up With That” tend to show less impact than we would think.  I find both the article and the comments significant food for thought.

http://wattsupwiththat.com/2012/03/16/volcanic-disruptions/

From Western Geo Hikes – reference map showing all calderas in San Juan Volcanid Field and their dates of origin. http://www.coloradogeohikes.0catch.com/Colorado/SJVF/SJVF.html

From Western Geo Hikes – reference map showing all calderas in San Juan Volcanid Field and their dates of origin.
http://www.coloradogeohikes.0catch.com/Colorado/SJVF/SJVF.html

The second observation would be that massive release of volcanic material into the environment (Large Igneous Province outbreak) does not necessarily lead to a massive global temperature change or extinction event.

http://www.largeigneousprovinces.org/13aug

A third observation would be that existing volcanic activity needs to be supplemented with some other massive insult to the planet to trigger a long-term change in climate or an extinction event.  And that additional insult, whether impact event(s), close supernovae or other interstellar event, must be sufficiently large so as to push an already stressed system over the edge.

A final observation is that we know that this planet gets hit by impacting bodies at some currently unknown rate.  That flux of bodies is not limited to asteroids whose orbits are (mostly) known.  They also comprise comets and the remains of fragmented comets whose orbits we find out about the first time we see them days to months before they arrive in the inner solar system.  They can be significantly faster than asteroids and are not limited to orbits near the plane of the ecliptic.  And these bodies can be very large.  Comet 1993 Hale Bopp was some 25 miles (40 kilometers) across.  We have yet to characterize either the population or the danger posed by these bodies.  Note finally that the majority of meteor showers take place when the orbit of the earth crosses that of known comets.

My conclusion would be that as large as possible volcanic eruptions may be, even they need help from one to many somethings equally or more powerful to push this planet over the edge into massive climate change or mass extinctions.  All of which makes me a lot more comfortable about ignoring the incessant hectoring from the environmentalist community.  This does not mean we shouldn’t be Good Stewards of our home.  We absolutely should.  But our home is a whole lot more stable and resilient than any of us suspects.

Thanks for reading and I look forward to your comments.

AGIMARC

Additional reading:

http://gsabulletin.gsapubs.org/content/120/7-8/771.abstract
http://petrology.oxfordjournals.org/content/43/8/1469.abstract
http://petrology.oxfordjournals.org/content/46/5/859.abstract
http://gsabulletin.gsapubs.org/content/81/8/2329.short

274 thoughts on “What happened at the end of the Eocene?

  1. Thank you Agimarc for this rather stupendous Christmas read. I guess it will take towards Boxing Day before people have finnished reading 🙂

  2. As I am a christian, I believe that God crated the heavens and the earth. And that the earth was hit by an enormous cataclysmic event, Noah’s Flood which had an enormous impact on the whole planet. During and after the Flood there were rapid plate tectonics, also called Catastrophic Plate Tectonics. These tectonics caused massive folding, buckling of the deposited strata during the Flood, creating huge mountain ranges like the Andes, Himalayas, Cascades, asf. Massive rifting and seafloor spreading also occurred. When the Flood waters receded into the newly formed ocean basins, the surface of the continents were eroded, creating canyons like the Grand Canyon. All these tectonics also caused super-volcanism on a massive scale which waned during the centuries after the Flood. Ashes erupted by these supervolcanoes darkened the sky, causing a single Ice Age.

    If you want to know more about this, take a look at http://www.icr.org, http://www.creation.com, http://www.answersingenesis.org/

      • The cataclysmic Noah’s Flood happened some 4.000 years ago. It was a judge from God over the sins of the fallen mankind. But God gave His only begotten Son Jesus Christ to this world to redeem the mankind from sin and judgement. Therefore He died on the Cross of Calvary and on the third day he rose from the dead to give eternal live. He ascended to heaven from which He will return very soon. Before the Second Coming of Jesus Christ, the earth and all mankind will be judged during the Great Tribulation when the antichrist rules the world. In this period the earth will be hit by asteroids and comets, massive volcanic eruptions will occur. But before the Great Tribulation will start, all born-again believers who believe in Jesus Christ will be evacuated from this planet.

        DragonEdit: Let us try to stay scientific. Religion is good for those who are religious. But this is a site for science and scientific debate. A bit of OT on other subjects are of course fine as you know. But, I think we should thread lightly on walking down this path of discussion, after all religion is not the subject that brought us together.

        • Born again?
          Does that imply that only Zombies will be evacuated from this planet? I must admit that it would be a handy way to halt the impending zombie-apocalypse.

        • Mast –

          Also a Christian here, but I am interested in how things work. Best I can figure out, science tells us where, when and how. Religion tells us why. They are not mutually exclusive pursuits.

          The 7 Plagues have been tied at some level to the eruption of Santorini. The Great Flood has been tied by some to the opening of the barrier and refilling of the Black Sea after the end of the last ice age. Some of the impact people tie the legends of Gilgamesh and similar flood legends to a large water impact in the Indian Ocean. There was a reason that the ancients got freaked out by comets and I wonder if they got pounded by them on a not so irregular basis. Best wishes for a very merry Christmas to one and all. Cheers –

        • Cannot be 4000 years old. Sorry. As some trees are 5000-9000 years old. And you count the rings on their wood. That means that 4000 years ago, the Earth had not a large flood.

          Go tell this to this tree in Sweden, or to other trees in the US and Middle East, way older than 4000 years old. You can even count more than 4000 rings if you would had the patience.
          http://en.wikipedia.org/wiki/Old_Tjikko

          The ice age is definitively around 8000-10.000 years ago. We don’t need science to tell us that, many geological records can be read by the average joe like me. In Iceland, you can also clearly see the record of that in soil profiles, the entire history of my home place in the last 10.000 years. Obviously there is more history before the ice age. A lot more.

          However, I can tell you something. There has been theories that actually several “the flood” events happened since the ice age. Greek mythology described 3 biblical floods, which actually can fit to geological record. http://en.wikipedia.org/wiki/Ancient_Greek_flood_myths

          Plato spoke of the first one, the Ogyges flood, around 10.000 years (impressive how he got the age correctly), that is the flood following the end of the ice age, as large ice caps melted, probably catastrophically, either by rapid global warming, which could have been caused by a comet impact (unconfirmed still)

          The other 2 big floods that followed, could be link to some large floods that actually happened. The black sea flood for example, some large tsunamis, or even an impact event in the Indian Ocean. Actually the flood could have been this http://en.wikipedia.org/wiki/Burckle_Crater

          Around 2500-3000 BC (so near the biblical date of 4000 years ago), a large tsunami/ flood happened across most of where humans lived back then (except the American continent), this created myths of one large ancient flood created by fire in the sky, in places like Aborigenes in Australia, tribes in Africa, and of course throughout the Middle East and India. This is the biblical flood of the Bible. But another one also happened 10.000 years ago, the largest one spoken by the Greeks.

          Sadly, the situation was this: The Greeks had a quite good knowledge of science (just look at its knowledge of the Holocene history and their floods, they knew the earth was round, they had knowledge of the atoms, and they knew correctly a lot of other stuff). Then came the Romans and they were too drunk, indulged in pleasures, and not so much interested in keeping facts accurate. Romans were a civilization of pleasures not knowledge. When they wrote the bible, they add some wrong facts into it, but they only wanted to write a book for the Christians. The Greeks would have written a more accurate bible. Don’t mean to offend anyone.

          • The greek 10K is from when the Med refilled as the water levels rose in the atlantic. Was the largest known waterfall when the Atlantic burst through.

    • I’m not against religion (honestly), but I’m always amazed how so many people (christians and atheists alike) try to warp science to fit into their pre-determinted world view.

      It’s one of the biggest no-no’s in science or any analytical study where you only look for affirmations of your pre-conceived notions, instead of letting the data & results speak for themselves. Personally, I think it’s silly to take the bible (or any large religious manuscript) verbatim. Regardless of the accuracy of any religion, when you pass texts down through 2000+ years of re-translation, re-interpretation, political agendas, and cultural influences, you get a huge pile of innacurate rubbish. It may make for a good story, but not really a particularly accurate text. Most Christians should be able to see this through the glaring differences in the new testament (it’s newer) and the old testament (which reads extremely different than the new testament).

      With that said – lets keep religious talk off here. This is a scientific blog. If you want to discuss religious theories, that’s fine, but I don’t think this is the right place for that 🙂 .

    • I guess the pilot was distracted by the hypersonic Santa-sled taxing down the Runway with a huge honking red light up infront… :mrgreen:

    • Fender benders in aircraft get expensive. Similar thing
      happened to a C 130 at Winslow Az, -took the roof off
      of the restaurant…

      DragonEdit: Edited together the comments! Merry Christmas TG

    • Probably in a bit too much of a hurry to get out of JNB – an unpleasant airport in my opinion.

      Here’s a novel dual-use structure: an office building that doubles as an A380 wingtip remover
      (Paris 2011, the A380 was being towed. A quick inspection and patch-up and it was flown home to Toulouse without its wingtip)

    • Are they?
      If you are talking about the last comment staying where it is, it is because of a bit of Dragon Christmas Magic! :mrgreen:

      I stickied the Christmas Greeting so that it will always be last.

      • Well, that is what I’m seeing. I figured it was something a wee bit nefarious on your part. 😀

        The whackedness that comes from comment sequencing errors I have not seen.

  3. Thanks for the great post, Agimarc!
    Merry Christmas everyone!
    I wish that 2014 will bring us all many pleasures, beautiful fireworks from innocuous eruptions and all the best you can possibly imagine!
    My next comment will probably be from Europe, so, see you guys soon!
    Feliz Natal e Próspero ano Novo para todos!
    Renato Rio

  4. What a fabulous read this is going to be! Will be perfect to digest along with my Christmas Eve dinner (out here in San Francisco, Crab Cioppino is a traditional feast….the tomatoe/veggy-based sauce is made the previous day, then the shell-fish(s) and whitefish fillets are added later). Every recipe is different, since the name “Cioppino” came from the Italian fisherman that used to “chip in” some of their catch into a big stew pot out on the wharfs, then all would gorge themselves accordingly. My own recipe is nearly 50 yrs in the making and features all hand-chopped fresh herbs and spices. Given the price of crab and shellfish nowadays, we can only afford one Cioppino a year, but OHHH BOY, is it worth the wait! A big (huge) bowl of cracked crab, eastern clams, west coast mussels, prawns, tiger shrimp, bay scallops all swimming in oodles of thick sauce with genuine San Francisco Sourdough all washed down with a fine California Chardonnay. Doesn’t get any better than this..anywhere, anytime.

    Off topic for moment, but assuming this new spate of seismicity from El Hierro is for real, it would fit an emerging trend of spikes in seismicity occurring approx. every 9 months or so. I believe this periodicity may be indicating a fairly linear rate of magma pressure from below, which builds up over a 9 month period of time before a “critical” pressure at depth is achieved that fractures the overlying cap and allows dikes emplacements to occur. As result of the magma dispersion (mostly lateral), magma pressure is reduced, and the cycle re-sets. Given the continuing linear rate of magma injection (since 2011 anyway), I would think there is little reason to believe magma injection at depth will cease any time soon? Also, I wonder if we can infer that because the underlying rock fractures at a relatively lower pressure than the topmost layer of crust, then pressure cannot build up enough to cause a massive surface eruption? (at least at this time).
    I made a graph of the peridocity, but I can’t figure out how to post it in “comments”? Maybe some “Dragon” assistance would help?

    Image and video hosting by TinyPic

    DragonEdit: There you go!

      • Agreed completely about the scarcity of data. Three data points is hardly “proof” of anything. It will be interesting to monitor the data over time to see if we have a working theory or not.

    • Hi Craig

      It sure bears watching.
      Try a Sauvignon for the sea food. It is what is nearer to the Graves appellation in Bordeaux and the white ones are really top with the seafood.
      If you can supply the recipe of the cioppinno, I’m sure a lot of people would be interested.

        • A good cab is used early when making the sauce, and provides a wonderful complexity to the flavors. Other variatals also work well, which is one way I make the Cioppino different year-to-year.
          Since my Granddaughter and I are making up the Cioppino sauce today (cooking Ciopinno around my house is a family affair), I’ll try to document it as I go, then forward it out. I’ve never written this down, so now is as good a time as any to try. Maybe try to include some pics if a Dragon can help post the images.(Carl, thanks again for previous help)!

    • Wife and I enjoyed a meal like that at her cousins place
      in Port Orford where we met and married . Cousins late
      Husband was a real live, Cajun. A fisherman and crabber.
      He made a dinner like that but with a Cajun bent. Hoo-boy!

    • Weird, I only see now your comment, but I found that site at around the moment you posted this. Telepathy?
      See below where I posted it too.

            • not bad, but one little remark:
              *bi-jen= correct if you write it like some (flemish) people would pronounce the word, but normally you write ‘beetje’.
              bijen in dutch means ‘bees’,
              (there can be a big difference between writing language and speaking language, certainly in Flanders)

            • I see that

              Interesting, as the teacher is dutch, I’ll check. I’m all muddled up with my bit of german and my olde english

            • Dutch is fun, it is one of the few languages that I can read and get 99 percent of what is written. But as soon as someone starts speaking it, good night…

            • @Carl, The Dutch speakers have the same problem 🙂
              I don’t know how many people you heard speaking, but there are a lot of dialects in Dutch. Normally people write (and speak formally) in Algemeen Nederlands (standard dutch). But in Flanders people from Brabant doesn’t understand people of west Flanders (unless they are doing efforts to keep out their accent). and then you have also the Limburgians who use in their dialect ‘pitch’, so that also sounds like chinese for us. And this is only in Belgium.
              In the Netherlands, some people thought that we were German when they heard us talking. While we were speaking the same ‘language’. We had to speak slower and ‘cleaning up’ our language before they understand us.

            • It is peculiar also on the french speaking side in this area. Sometimes it’s back to Charles le Téméraire. We should do some tours with linguists with Sa’Ke on both sides of the linguistic frontier. I went to waloon brabant and the french “patois” is wierd. But it is a small area. Sissel will speak Limburgian and be the referent here, She has a familiar which is a Mososaurus.

  5. By the way, great post Agimarc! I’m with you in your fascination of world-changing events in that they’re incredibly interesting, mostly due to the fact that they’re still largely mysteries. Unfortunately, it can be an uphill battle to fight against “doomers” and those who wear tinfoil hats, but that just comes with the territory.

    As for whether volcanic events or impact events alone can trigger extinction events, I wouldn’t be so quick to write off volcanic events alone being able to cause mass extinctions.

    One striking correlation for extinction events is that there is a high association with oceanic anoxia and planetary extinction. Oceanic anoxia can be caused by a variety of things, but it’s pretty widely agreed upon that Large Igneous Province style eruptions can lead to anoxic oceans, mostly due to the ridiculous amount of sulfate gas that is emitted during these eruptions. Mass death in the oceanic systems then leads to a chain reaction in the planetary food chain.

    Then there is also the theory of the association of impact events & large igneous provinces to consider (whether antipodal, or at the spot of an impact). So in other words, while it may look like from afar that it requires more than one event to cause an extinction level planetary change, it’s very relevant to keep in mind that sometimes one big event leads to another big event, which causes a chain reaction until the planet is able to re-stabilize.

    There are quite a few “runaway freight train” scenarios in climatology, where if you push a single environmental system past it’s threshold of self-correction, it then affects other inter-related environmental systems, which then also affect other inter-related environmental systems. It’s a fascinating topic, but incredibly complex, and only theoretical at this point however.

    • cbus – thank you for your kind words. Your thoughts are why I included the cart from the LIP Commission about LIPs and extinction events. On the right hand side of the graphic, there are 3 modes of climate excursions listed – Icehouse Earth (ice ages), Greenhouse Earth (warm temperatures), Hothouse Earth (climate disaster heat – think Permian – Triassic event). The article can be found at the link to follow. I think it is fascinating. Merry Christmas to you and yours –

      http://www.largeigneousprovinces.org/13aug

    • cbus re: “it’s very relevant to keep in mind that sometimes one big event leads to another big event, which causes a chain reaction until the planet is able to re-stabilize”.
      The statement that the planet can even “stabilize” at all suggests that all things contributing to climate are both independent and yet intrinsically related, and together exhibits a closed loop behavior. If you change just one variable, the entire loop changes along with it (i.e. re-stabilization) even though other variables may remain unchanged. So I’m not so sure it’s simply a matter of one-thing-causes another to happen, but rather a shotgun/cummulative effect of many variables all interacting at that precise moment in time.

      • I would like to point out that the idea that “stabbillity” is the default for earth is wrong. Instabillity and ever-changing is the default state.

  6. “…group of people investigating the possibility that a comet storm caused a continental level extinction event over North America some 12,000 years ago…”

    Funny that. Some of those who oppose that idea claim that there is no impact crater or smoking gun. Proponents of it point to the “black mat” layer found at some Clovis sites. The parry for that has been that “we didn’t find any iron spherules when we looked at it” to which the counter is that “you didn’t do it right you dumb ass.” Tit for Tat aside, how about this?

    This 14,150 kilograms chunk of iron/nickel does not have a known crater. The general idea is that it impacted somewhere on the ice sheet and was then transported and dropped as a glacial erratic. Another large meteor with no crater is Cape York meteorite (58200 kg) and friends. The Innuit were using it as a source of iron for tools and hunting implements prior to it being located by Robert E Peary in 1894.

    And then there are the Carolina Bays.

    Intrigued by the seeming alignment of the bays, I set a collection of straight line paths along their long axis and looked to see if they converged. They did. Somewhere over Washington State/Idaho. I imagine that if actual survey data were used to replicate my action, a more firm location and statistical variation could be done to see where the apparent origin is really at. IN MY OPINION, the bays are the result of a bollide break-up over the NW US area… somewhere between Vancouver and Yellowstone. (in this case, Yellowstone is just a point of reference since most people know where that is at).

    BTW, Fantastic post! … and I don’t consider the Rio Grande rift as a failed feature. I think it’s merrily tucking along. That’s why you keep seeing quakes in Colorado as the crust along the eastern edge slowly tears apart.

    • Thank you, Kind Sir.

      More on Carolina Bays: http://cintos.org/LiDAR_images/index.html

      There are another grouping of them in Nebraska. Align the long axes and you end up with the impact site somewhere in northern Michigan.

      Some posit that there were two centers of airbursts, one in central Michigan, the other in north central Mexico. Fascinating detective story. I’m still trying what the heck a trap door caldera is.

      Best wishes to you and yours for a very Merry Christmas. Cheers –

      • Trapdoor caldera. One that only opens along 3 sides when the roof collapses. In other words, the ring faults never fully circle the roof. The un-fractured side acts as a hinge.

        • Geo – that’s where I am confused (regularly and easily confused here).

          To me, having one side of a caldera acting as a hinge implies the floor of the caldera is one piece that acts as a flat plate being lifted by the forces of degassing magma underneath. I don’t think the rock is that structurally strong, as rock is a lot like a poor concrete – great in compression and awful in tension and filled with cracks. If you have the floor of the caldera acting as a trap door, then the top of the caldera is being loaded in tension as it is blasted upwards, or more complexly, being flexed by the varying forces of the eruption.

          The other thing is that if one side is acting as a hinge, that implies the ring fracture goes all the way around.

          Probably not saying this well at all, but I am confused and remain confused. Will keep poking around ad see if I can run across something that makes more sense. Merry Christmas to you and yours. Cheers –

    • There are also the Grady or Citronelle ponds in NW Florida and South Alabama, though I have yet to find a comprehensive listing. I have told my stepson to keep an eye out for oddball features when he is out hunting and to jot down where they are if he finds any. I don’t think it will work though, Buck Fever tends to make people forget things.

    • Interesting stuff lurking!

      From wikipedia – http://en.wikipedia.org/wiki/Carolina_bays

      “It said that the Carolina Bays were created by a low density comet exploding above or impacting on the Laurentide ice sheet about 12,900 years ago.[1] However, this theory has been discredited by OSL dating of the rims of the Carolina bays, paleoenvironmental records obtained from cores of Carolina bay sediments, and other research that shows that many of them are as old as, or older than, 60,000 to 140,000 BP (Brooks et al.1996, 2001, Grant et al. 1998, and Ivester et al. 2002, 2003, 2004b).”

      You sure they’re still impact related structures?

      • I don’t know how they dated those rims. However, remember that this area is over run by hurricanes on a pretty regular basis.

        My view of them as impact residue is based on the odd alignment of them. I don’t know of a process that can do that other than a strewn field. When they formed is the biggest issue. At a date that old would probably place them before Clovis, and that would be the biggest issue contradicting my ideas.

    • The Willamette meteorite is an amazing intact space rock.
      A local native tribe tried to claim it. Said it was a “sacred object”
      From the sky. How they figured that out especially when it was
      Initially buried, I haven’t a clue.they wanted to place it in a venerated spot- the lobby of the local casino. Museum said no,
      But,you can visit any time. End of effort.
      Now on to our local quake near la Grande. Quite a few felt it
      That lived in the alluvial area s of the city. No word as to
      anywhere else.

        • Liquefaction indeed fill from dredging the river and
          Freeway construction. On top of the alluvial deposits. All of that area. It was North la Grande
          That felt it the most..

    • Booyah! Voof! Drooling over that picture… I want to do weird and bizarre tests on that one while laughing menacingly…
      Okay, I am most likely some sort of mad scientist. So sue me 🙂

  7. Hi

    This is the earhquake update for December 2013, up to the 23rd @13h07.

    The first part is an event by event evolution (showing event position, magnitude, day and hour), then there is a 360° rotation showing all the quakes. At the end of this sequence, the former quakes (meaning since 31/05 and up to end of november) are shown in black.

    The following sequence show a vertical rotation ending on a still frame with a view from the top and back. Then there is a progressive zoom centered on the last event.

    Note that the mythic island of San Borodon is visible by a graphic artefact @ 1’11 and 1’18 :wink:.

    http://en.wikipedia.org/wiki/Saint_Brendan's_Island

    Earthquake magnitude is shown (see scale on the side), and date is shown also (see left side of colorbar).

    The terrain elevation is given by the scale on the right of the colorbar.

    There are a quite a few quakes which appear to be at depth 0, near the parador (Las Playas). This is not the case, they are only quakes for which the depth could not be calculated precisely.

    Data from IGN, NOAA, made on Gnu Octave

  8. Very interesting reading!

    About extinction models and climate change: I read somewhere that in some cases (I don’t know which extinction event), climate change was caused by a change of the tilt of the earth’s axes. Even a small change (say 28° instead of 28,5°) can change the climate. Of course if the earth is getting hit repeatedly by meteors/comets/… that can cause a change of tilt.

    • Not by very much… Take (for example) a 10 km wide iron meteor moving 45 km/s at a 45° impact angle, striking crystalline rock.

      Major Global Changes:
      → The Earth is not strongly disturbed by the impact and loses negligible mass.
      → The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).
      → Depending on the direction and location of impact, the collision may cause a change in the length of the day of up to 10.4 milliseconds.
      → The impact does not shift the Earth's orbit noticeably.

      Via the Impact Effects Program

      But… you do get a 249 km diameter final crater and 26700 km3 of material melted/vaporized and ejected into the atmosphere (and orbit). Oh, and about Mag 10.6 (richter) shaking within 500 km of the impact site… but you probably won’t notice it due to the 475 psi dynamic overpressure that comes along in about 25 minutes. Well large enough to rupture some body parts, such as eardrums etc. (houses explode at about 2 to 3 psi dynamic overpressure)

      Oh, and since 500 km is within site of the fireball… the radiant heat from it will be about 1780 times that of the sun. So great that trees will just burst into flames. (It would be the Flashover of all flashovers for you firefighters out there.) {I’ve been in one of those, they are spectacular, but are not any fun. By the time we had retreated to the top of the stairs, the whole floor became covered with flames.}

      • People tend to forget that earth tilt is cumulatiive. As time goes by we will sooner or later land with earth being at a 90 degree angle, and at the same time we will get increasingly tidal locked. Bad part, north will be the outer part of the tidal locked earth. Good part, that will happen about the same time the sun bloats up and swallows the planet… No biggie, it is just The End. :mrgreen:

  9. Hmmm…

    Actually there is only one “trapdoor volcano” on this world. It’s at a place called Manuel Benavedes. And it’s just south of the Mexican border, and right across from Big Bend Ranch State Park in southwest Texas. And it was an American geologist named F. W. McDowell who proclaimed that we are looking at a giant 17 mile “trapdoor”, not a Mexican. And he makes this assumption without any consideration whatsoever for the crazy mantle physics required to produce a 17 mile wide, perfectly semi-circular trapdoor vent; much less any consideration of the structural integrity that would have to exist in the rock of that “trapdoor” in order for the thing to have opened, and closed repeatedly without breaking.

    See:

    McDowell, F. W., 2010, Geologic Map of Manuel Benavides area, Chihuahua, Mexico. Map and Chart no. 99. Geological Society of America, Boulder, Colorado.

    Abstract:

    This map and text cover an area of eastern Chihuahua state adjacent to the Rio Grande and the Big Bend of Texas. The area contains an 1100-m-thick volcanic section very similar in lithology and age (by Ar-Ar dating) to that exposed in both Big Bend National and State Parks. This includes, from older to younger, a heterogeneous sequence very much like to the Chisos Formation, a thick locally derived rhyolitic flow complex comparable to the Tule Mountain trachyandesite, distal thin ignimbrites similar in age to the Mitchell Mesa ash-flow tuff (the largest unit in the Trans-Pecos volcanic field), and a caldera source for both the 31 Ma San Carlos tuff and the 28 Ma Santana tuff. The caldera is an unusual trap-door type with a hinge zone on the southwest and two separate collapse and eruption margins around the north and east. Its outer diameter is approximately 25 km, which is unusually large for the tuffs that erupted from it, suggestive of a shallow collapse. Inflation or tumescence prior to the eruptions modified a preexisting Laramide fold by bowing it outward toward the north and east; a 31.5 Ma granitoid was intruded into the fold axis, resulting in the formation of skarn deposits in the surrounding limestones of the fold.

    The map itself consists of two crude hand drawn maps with all the data resolution of a comic book page, and done by a couple of graduate students back in the eighties. In 2010 Mr McDowell simply kludged the two together into a single map. That map has almost no correlation whatsoever to actual geologic features clearly visible in modern hi resolution satellite imagery, and verifiable from the ground. And McDowell completely disregards that modern satellite data because it just isn’t supportive of his too many unsupported assumptions, and suppositions to count.

    There is no question that something different, and inconceivably violent happened there. But as for me, I prefer to think of it as a “pseudo explosion” structure not a volcano; leaving the door open for further study to determine what really happened there without all the unquestioned, gradualist-assumptive reasoning.

    • Ring fault that hasn’t faulted all the way around. Combine that with a bit of local spread zone and you do not need to postulate weird hinged giant slabs that are only 1100 meters thick (which would have broken like a crumbly cake.
      Basic physics 101 course on DVD seems to be a good christmas present for McDowell…

    • Dunno about that being the only one. It may be the only studied and proven one. There are three caldera structures in SE Spain, one of which seems to be a trapdoor. This became evident while reading an article on mineralization of one of the three calderas. (and why the other two weren’t)

  10. And since it is Christmas… Here is the official VC Santa live from Dr Morataya.
    Not easy to be Santa Claus when you suffer from a bout of diarrhea. Cutest Santa I have seen so far, but then I suffer from a really big soft spot for children.

    Image and video hosting by TinyPic

    • I call them screamers. Your gastrointestinal tract says “you got to go, NOW!” but the effort is either non productive or mostly phreatic. If you are lucky, you don’t spray down the side of the toilet (and your LZ) when you try to sit.

      *yeah, I know that phreatic refers to ground water, but in the end, that’s what it’s gonna be anyway when you are finished”

      • Apparantly Santa got better a bit later and could leave the hospital.

        I am feeling sorry for Carmen who took the picture. She will be spending a 36 hour shift in the emergency ward of the Childrens hospital she works at. So, basically no sleep and no food during the entire Christmas for her.
        It makes me want to punch out the living daylights of the idjit that came up with that particular idea. Okay, I understand the shift thing. I could even live with the amount of hours. But banning the staff from eating or napping? That deserves a real round kick to the head. Something I think I will rectify one day when I get the opportunity with the best regards from the tripple entity of weighing 96kg, 30 years of martial arts training, and a bunch of instructors who was teaching nasty ways of hurting people.
        If I had even been in the same country I would have snuck in with food during the night.

        At least I hope that all of her patients are as cute as Santa above. (yes, I have a terrible soft spot for children. Oh, I had mentioned that allready… well, sue me)

          • Well, I guess it is the same. Marriage is like the army. On occation your CO will tell you to do something gruesome to someone. And sometimes you are expected to take initiative on your own and do something gruesome to someone.
            And when you have done it you know your CO will give you crap for it. But if you hadn’t done it you would have been given a dishonourable discharge from your CO (divorce).
            So, marriage requires martial arts training because trust me… when a guy comes up and grabs your wife on her familly jewels… You’d better punch that guy out. Otherwise you are history as a husband, but at the same time, expect her to tell you that you are an idiot for punching the guy out. So, I guess the question is… Do you want a scolding and still have her around?

            Genetics, we men are always at the butt end of it.

            And no… I could not do an epic split unless two trucks pulled my legs apart… 😉

  11. Speaking of the San Juan Mountains, I took this photo a couple of years ago while riding our atv on Owl Creek Pass near Ridgway, Colorado. Love this view of the eroded ash. I’ve never seen anything like this before in person.

  12. Thank you agimarc for your magnificent post! It´s mindboggling that humanity, or any intelligent species that may roam Earth in the future, may one day have to deal with these huge events, especially comet impacts. I hope we have our best minds together when that moment comes to mitigate the effects and not have used up all our resources in narrow-minded wars.

    Peaceful holidays to everyone!

  13. Merry Christmas to all all over the World, one special greeting from Stormland..
    It seems the “perfect” storm is heading beside Scotland but past Iceland *so we only get normal freaking winter+snow+storm that barely missed.
    Hope VC’ers in UK stays safe and Wellingtons be not needed, except for travelling

    (PS. That said I think Mrs. Hekla vill be on vacation in the Canaries over the holidays, and new Year, but do not know if she will be staying much in El.Hierro, but if there is tremour, that might indicate she has arrived.)

    • I am not at all happy with that perfect storm!!! We have force 11 gusts down here on the south coat of England and my son who should have been home by now is still stuck in Cardiff Wales because the rail line between us if blocked with fallen trees and also flooded. Maybe he will be home tomorrow, maybe not! 😦 Wont be a happy time for me if he doesn’t make it home tomorrow as no trains on Christmas day. Still counting my blessings he is safe and well which is all that really matters in a storm this bad.

      • Sadly two people have already died in the UK drowned in separate incidents. Keep safe everyone as that is even more important than being with family at this time.

      • With luck, no one will break anything tomorrow. Today I had a toasted PC and a crapped out printer. Since all of those types of offices will be closed statewide tomorrow, things are looking up.

        I’d like a bit of time to get shitfaced, but usually I just get tanked and get into a heated argument with myself. Then fall asleep.


        Unrelated. Tonight, my wife said to me “Why are you always standing up for the dog?” I responded, “Because no body else will!”

        This was due to her being mad at the dog. (the big one) I tend to intercede on his behalf after the one of the little rat dogs starts a commotion around the house, such as antagonizing the neighbor’s dogs into a barking frenzy. The big dog could really care less, but eventually will join in.

        My defense of him is due to his getting set up by the rat dog, and the fact that he is still an adolescent… though about two years old. My “like” for him stems around the fact that if I do have an intruder… he’s gonna buy me time to get to a weapon. I’m gonna stand up for anyone that watches my back. Even if it is the dog.


        Side note for “young punks,” be wary of the “old” man. Older men have had time to look around and puzzle out what things around them can hurt. They (we) won’t hesitate to use such objects in an altercation. The idea is to stop the threat, and many of us will take the most expedient path to do that. It’s not that we are planning for a fight, we just don’t like stepping on things or brushing up against stuff that hurt. My first encounter with this phenomena was when I was much much younger. Anorther Kid popped me in the face and drew quite a bit of blood. (square in the nose) By the time the coach intervened, I was in the process of beating him with a table. I was still a geek afterwards, but he never lifted a finger at me again.

          • personally I prefer a toasted cheese and tomato sandwich but then….. each to their own. 😀
            I am sure a toasted pc can be tasty for the right people! ROFL. Thanks again.

            • Haha, I remember that smell! I used to work in the test department of an electronics firm. When you heard the sizzle you got your head out of the way quick before the capacitor exploded!! I was always amazed no-one was badly hurt!

        • Hmm… I’m one to keep an ear out for strange sounds. Stuff that is out of the ordinary. Just heard a single report from a distance. I hope that someone is playing with fireworks and that wasn’t a shotgun. (which it sounded like) Gunfire around Christmas is not usually a good thing. No light flicker, so it was probably not a transformer.

    • Its not good travelling weather for Portugal, northern Spain, western France, Ireland, UK, Iceland.

      Anyways, a happy Christmas for you all!!

      • The West Fjords region in Iceland will be apparently isolated from the rest of Iceland, for the Christmas time. I just saw it in the updated road map conditions. Its quite normal, but those wanting to go there, will have to take the plane.

    • Happy holidays Islander!

      I guess we will get the weather around late tomorrow or Christmas Day. I would prefer tomorrow since I will be indoors celebrating Christmas (we do it on the ‘eve and not the ‘day in Sweden).

  14. AGIMARC, nice post! a great read!

    I am starting to agree, in face of evidence, that single large volcanic events do not result in extinction events. Perhaps their impact in climate is rather short-lived.

    However, what we face nowadays for Earth species is a different story. Many species are being set on course towards extinction because their habitat is being greatly reduced, fragmented, and even eliminated. The impact of global climate change can be some, but much less compared to habitat destruction.

    I think we all can agree with this. Its not that all species will be extinct, but many will. Obviously, cats, dogs, skirrels, ants, and many other species will be fine, but some primates, whales, tigers, bears, will be extinct in the decades ahead. And that is very sad.

    Its complicated to revert this trend in the decades ahead. I cannot just imagine cities and surrounding farmland disappearing just like that. Over the next centuries, I believe there is going to be a great effort in reverting this. And hopefully, with dna technology, some extinct species might be brought back to life. But its difficult to imagine how the world is going to be 500 years from now, judging from the very fast pace of change.

    A world without humans because of a virus or a nuclear war, or a world where there is little nature left due to so much tech and artificiality around, or a world where humans are escaping to space and trying to preserve more the planet, or anything in between. Less likely is that is going to be a world similar to now, or any of the centuries before.

    • Bears, depends on what type of bears. The polar bear might be horked (but will most likely adapt). But the brown bear is doing fine. Here they are almost a plague, thankfully they are rather peacefull buggers unless you shoot them…
      In general I do agree with you though.

      My favourite animal is the meyrkat. If we go extinct they are my favourites to take over the show. Proto-language and a broccas centre, thumbs that are pretty much opposable, using tools, social group animals that take care of young and old in the group… and they take shit from nobody and nothing. A group of meyrkats do not back down from a lone lion. Yes, they can’t beat the lion, but they bugger it from behind untill it decides that somewhere else is a better place to be in.

    • relatively anomalous” ???

      @Carl, wouldn’t a steadily increasing Radon level indicate an approaching source for it? (Same for CO2)
      For all: Radon is one of the byproducts of uranium or thorium decay. Radon has a half life of 3.8 days, so once it forms, it doesn’t stick around as Radon for very long.

      From the above linked paper.


      “permanent network INVOLCAN geochemistry instrumental in Meridian Island has detected relatively anomalous radon emissions (222Rn) and carbon dioxide (CO2) before registering the recent anomalous seismic activity since December 22, 2013.”

      (Gurgle translated)

      ASSUMING that “Meridian Island” means the middle of the island, that would be just east of Tanganasoga would it not? (SE of Frontera, though I don’t know where the sensor is actually at) Tanganasoga is where that strange circular region devoid of early quakes was at that I interpreted as the outline of an old plug/dome like feature.

      • Have heard this be the case of increase in Radon Gas.
        If at or near Hekla < scramble !
        *BBGN but will look you up in the morning.
        *"Perfect" storm be irony on my part.
        *Hope all get safe and in good time.

      • Uhm… Radon is not good for many reasons.
        Yes, Radon is a precursor gas for magma rising. And when it all of a sudden goes up almost ten times something has changed.
        Now for my second concern as a physicist. This is not healthy levels of radon. I would avoid being close to where they are measuring, this is 3 times EU health radiation levels in air. If a nuclear plant goes above 300 Bq/m3 all sorts of alarms go off, and if you have more than 700Bq/m3 in your house you need to evacuate it… One should though remember that the value is for longterm exposure. If it continues at these levels for a few days I would haul ass out of there to avoid lung cancer and other assorted minor pesky health problems.
        Tanganasoga is my favourite spot for the shit to hit the fan… It is the closest to being a central volcano that remains on the Island and it is smack bang on that old triple junction.

          • I would not phrase it like that. But something below is containing material that has a higher radiative component. Ie, that something has been radioactively decaying and while decaying it has produced radon.

            If you have a stable high radon level (as you do in parts of Sweden), then you have a source of uranium in the ground. If you have a volcano around and the levels go up there is a new source of thorium or uranium moving upwards, or water is passing close to a source… It is an indicator, but not proof of shallow magma.
            One should though remember that radon is a heavy gas, so it needs some sort of carrier to reach the surface if it is deep. Either other gasses at pressure, or water, if it is coming out of a volcanic system.
            If it is emaneting out of a uranium source it is probably a shallow source.

            But, earthquakes at depth, probable GPS-motion (we will know for sure in a few days) and radon… Pretty telling really that something is going on.

    • More on the “for all” bit. The immense heat of the lower layers of the earth is due to the energy of accretion from when the Earth formed from the parental dust cloud, from the impact of Theia which then formed the moon, (and Earth got most of Theia’s iron core to add to it’s own) and from radioactive decay of Uranium, Throrium (3 to 4 times more abundant) and from Potassium 40. (yes, all bananas are slightly radioactive)

    • Merry christmass everyone!
      Did they add information to the article?
      Anyway it states that the radon anomely was measured on HI02 and HI05, That’s the north west of the island (Sabinosa).
      Also elevated levels of CO2 are meassured at HI01, right above the swarm. But not at HI06and 07 (Tanganasoga)

  15. And these are the safery regulation values for radon.
    1. In a house, 200Bq/m3
    2. Nuclear powerplant, 300Bq/m3
    3. Underground, general 400Bq/m3
    4. Underground, mine 1300Bq/m3

    All of the above are maximum values. So… 2100 would be way to much for a prolonged period. Incidentally 2100Bq/m3 is actually higher than what Tjernobyl produced in Sweden when it fell to the ground (1400Bq/m3 on average).

  16. I’m not sure I buy that the Carolina bays were created by an impact. Maybe, maybe not. I’d be interested in seeing dating of what is UNDER them, not at the bottoms or the edges. If it is all from the same time period, then they were all created at once.

  17. If anyone is awake, Sakurajima is having a serious blast right now. Continuous.
    Great post, very informative. I have been reading about the Rio Grande rift lately.

  18. Merry CHristmas and a Happy New Year (or suitable translation to your preference) to all. May your eruptions be spectacular and non-fatal 🙂

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