New study blames underwater volcanism for catastrophic global cooling, famine, civil upheavals in Medieval times

This confirms what I’ve been saying years, that underwater volcanoes can lead, not only to cooling, but to ice ages.


Researchers presented underwater volcanism as the reason why the sky went dark for more than a year beginning 536 A.D. At that time, some parts of Europe and Asia saw the Sun for only about four hours a day, and even when the Sun was visible, accounts say it gave no more light than the Moon for 18 months. The dimming led to catastrophic global cooling, famine, and civil upheavals in Medieval times.

This period of darkness and cooling marked the beginning of a longer period from 536 to 555 A.D. as trees struggled to grow, indicating that the dimming was extensive.

536 A.D. was also one of the worst periods to be alive, according to Harvard University medieval historian Michael McCormick, who is not part of the study.

“People thought it was the end of the world,” said Dallas Abbott who studies paleoclimate and extraterrestrial impacts at Columbia University’s Lamont-Doherty Earth Observatory.

Abbott and her colleague John Barron from the USGS said their study of a Greenland ice core (GISP2) pointed to underwater eruptions near the equator that carried calcium-laden sediments and microscopic sea creatures into the atmosphere, which helped dim the sunlight.

“We found by far the most low-latitude microfossils that anybody’s ever found in an ice core,” said Abbott.

Thanks to Guy Wilson for this link


“New ice core evidence for a volcanic cause of the A.D. 536 dust veil” – Larsen et al. – Nature – DOI: 10.1029/2007GL032450


New and well‐dated evidence of sulphate deposits in Greenland and Antarctic ice cores indicate a substantial and extensive atmospheric acidic dust veil at A.D. 533–534 ± 2 years. This was likely produced by a large explosive, near equatorial volcanic eruption, causing widespread dimming and contributing to the abrupt cooling across much of the Northern Hemisphere known from historical records and tree‐ring data to have occurred in A.D. 536. Tree‐ring data suggest that this was the most severe and protracted short‐term cold episode across the Northern Hemisphere in the last two millennia, even surpassing the severity of the cold period following the Tambora eruption in 1815.


12 thoughts on “New study blames underwater volcanism for catastrophic global cooling, famine, civil upheavals in Medieval times”

  1. Robert, thank you so much for the highly interesting information. I think, that the mankind has been very lucky for the last 200 years not having anything similar to the Tambora eruption or the volcanic calamities of the 18th century. But now we witness increasing activity of the underwater volcanoes, and it is worrisome.

    • In August 2019, a large floating pumice raft covering 150 square kilometres (58 sq mi) was discovered in the tropical Pacific Ocean near Late Island in the Kingdom of Tonga.

      A pumice stone is formed when lava and water mix together. It’s a light-yet-abrasive stone used to remove dry, dead skin. A pumice stone can also soften your calluses and corns to reduce pain from friction.

      Some good things come out of a bad ones; cleaner feet. 😉

  2. The atmospheric polution from (in this case – Underwater) Volcanic action – which thus blocked much of the Sun’s Light (and therefore Warmth) from reaching Earth’s Surface – was so intense – that daytime was now akin to nightime…. Back when, folks noting how dark it was during the day – referred to that time as, “The Dark Ages”.

  3. Like I’ve always said, we think we rule this planet, but when this big old ball of dirt we live on gets tired of us, it will shake us off like a bad case of fleas.

  4. Fascinating topic, as it has been known for some time that something dreadful happened around 535 A.D., possibly a volcano, possibly a cosmic impact.

    Some theorize that the “nuclear winter” that ensued may have been caused by a fairly large comet or asteroid impact in the Indian Ocean, southeast of Madagascar, which may have caused the catastrophic tsunamis, perhaps a kilometer high, that deposited the enormous chevrons, composed of ocean bottom sediments, on the facing coast of Madagascar and massive tsunami deposits in western Australia. Whatever that event was, an enormous crater was recently discovered in the right place on the floor of the Indian Ocean, although no one has had the funding yet to do the necessary research to try to date the crater, which may date from 11,600 years ago (or even much earlier).

    If the crater was the result of an impact 11,600 years ago, in deep ocean, it might have put enough water vapor into the atmosphere and low orbit to cause a major greenhouse effect, which might well have been what suddenly ended the 1300-year Younger Dryas ice age that had also begun suddenly, apparently from a massive comet impact that vaporized much of the Canadian ice sheet 12,900 years ago. We do know for sure, from Greenland ice cores and nano-diamonds in those cores at that date, that some horrific cosmic event 12,900 years ago plunged the world into the Younger Dryas cold period, with global temperatures falling almost overnight by about 18 F., and something else happened (cause unknown) 11,600 years ago that suddenly caused a similar RISE in temperature, snapping the world out of the Younger Dryas and beginning the current (Holocene) interglacial period.

    There’s a great deal of excellent research going on in recent years that is going to require the re-writing of a lot of textbooks, when the authors (university faculties) die off in a generation. One thing is becoming apparent: it’s a dangerous world we live in, between super-volcanoes waiting to explode and large things falling out of the sky, and we are sitting ducks in a cosmic shooting gallery. The good ol’ Uniformitarian religion is dying a slow and well-deserved death, even in some parts of academia.

  5. dunno bout this one, it seems very “off” to me -theyre implying the foraminifera got aerial lift n drift?
    but there ARE terrestrial forms of those theyre not all oceanic only.
    if an underwater volcano erupted with enough force to lift the seabed critters thered be a damn sightmore than sulphur n teensy shells dumped
    as well as mother of all tsunamis leaving evidence as well

    and SUCH accuracy of + or – just a 2 YEAR leeway?
    for global coverage of such magnitude it would take quite a while to circle the globe and the nth sth poles and manage to dump on BOTH??? if it was nth by the time it got round to the sth particulates should have dropped out pretty much totally in rain/hail/snow/ or just gravity working surely?

    • I had the same thoughts, but not as technical as you.

      Being that the underwater Volcanoes are MILES deep, how did all the sediment make it up, without dilution, and with enough force to put them high enough into the atmosphere?

      It is hard enough for Terrestrial Volcanoes to put “dirt” high enough to noticeably effect the Global weather……..It takes a V7, V8 to do that? Yet, this underwater volcano not only did this but MORE than the V7, V8 since the research is saying it was so bad.

      What am I missing?

  6. And we now have some scientists arguing for geo-engineering to “dim” the sun’s incoming energy. Let us just hope that these fools don’t get their way.

    • Geoengineering no longer a conspiracy theory

      Researchers at Harvard have developed a plan to spray sulfur dioxide into the atmosphere to reduce global warming.

      “Solar geoengineering” would mimic the effect of volcanoes and reduce global temperatures.

  7. It’s the Gasses from Underwater Volcanic Action – which rise up through the water and out into the Atmosphere – which block Solar Irradiation – which Cools the planet..

    There appears to be some correlation between Sunspots and Volcanic Activity.

    AND There appears to be correlation between Asteroidal Impacts and Volcanism . aka as with Chicxulub and the Enormous Deccan Flats – both of Roughly 65 Million years ago (and AntiPodal) – with either being blamed by some for the wipeout of Dinosaurs (and other Life).. Either/Both event(s) would have had to have been Catastrophic to Life.

    ABRUPT DOWNWARD PLUNGES OF EARTH’S TEMPS .. can seemingly only be explained by a SUN Suddenly Shut Off .. Which can easily be explained by an Abrupt Atmospheric Blockage of Solar Irradiation – such as by Extreme Volcanic Actions..

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