Eight Times More Powerful Than Krakatoa...

I can't even begin to imagine the POWER of a volcanic eruption that was EIGHT TIMES MORE POWERFUL THAN KRAKATOA!  The results to London's population at the time were catastrophic.  Imagine losing a quarter or more of the people who used to live all around you...

And this was probably occuring all around the world.  But in the late 1200's record-keeping may have been hit or miss, some populations may have lost their literate compatriots (priests and monks, for instance).  Who knows?  Perhaps if historians begin to dig through what records are available, they will find written evidence for this climate-changing eruption. 

Mass grave in London reveals how volcano caused global catastrophe

Scientists search for the explosive source of a disaster that wiped out almost a third of Londoners in 1258

Dalya Alberge

The Observer, Saturday 4 August 2012

When archaeologists discovered thousands of medieval skeletons in a mass burial pit in east London in the 1990s, they assumed they were 14th-century victims of the Black Death or the Great Famine of 1315-17. Now they have been astonished by a more explosive explanation – a cataclysmic volcano that had erupted a century earlier, thousands of miles away in the tropics, and wrought havoc on medieval Britons.

Scientific evidence – including radiocarbon dating of the bones and geological data from across the globe – shows for the first time that mass fatalities in the 13th century were caused by one of the largest volcanic eruptions of the past 10,000 years.

Such was the size of the eruption that its sulphurous gases would have released a stratospheric aerosol veil or dry fog that blocked out sunlight, altered atmospheric circulation patterns and cooled the Earth's surface. It caused crops to wither, bringing famine, pestilence and death.

deaths required capacious burial pits, as recorded in contemporary accounts. In 1258, a monk reported: "The north wind prevailed for several months… scarcely a small rare flower or shooting germ appeared, whence the hope of harvest was uncertain... Innumerable multitudes of poor people died, and their bodies were found lying all about swollen from want… Nor did those who had homes dare to harbour the sick and dying, for fear of infection… The pestilence was immense – insufferable; it attacked the poor particularly. In London alone 15,000 of the poor perished; in England and elsewhere thousands died."

There does not seem to have been any explanation at the time; it was probably assumed to be a punishment from God. London's population at the time was around 50,000, so the loss of 15,000 would have radically changed the city.

Surprisingly, perhaps, the volcano's exact location has yet to be established. Mexico, Ecuador and Indonesia are the most likely areas, according to vulcanologists, who found evidence in ice cores from the northern hemisphere and Antarctic and within a thick layer of ash from Lake Malawi sediments. The ice core sulphate concentration shows that it was up to eight times higher than Indonesia's Krakatoa eruption of 1883, one of the most catastrophic in history.

Some 10,500 medieval skeletons were found at Spitalfields market, the site of the Augustinian priory and hospital of St Mary Spital, and the remains suggest there may have been as many as 18,000. The excavation between 1991 and 2007 by the Museum of London Archaeology (Mola) was the largest ever archaeological investigation in the capital. It was a member of that team, osteologist Don Walker, who discovered the link with a volcano. The findings will be revealed in Mola's report, to be published on Monday.

Vulcanologist Bill McGuire said: "This was the biggest eruption in historic times. It may have brought the temperatures down by 4C, a huge amount."

The Comments section is equally interesting and informative.

Evidence of Man in India 15,000 Years Earlier Than Thought

February 23, 2010 14:09 PM

Newly Discovered Archaeological Sites In India Reveals Ancient Life

LONDON, Feb 23 (Bernama) -- Newly discovered archaeological sites in southern and northern India have revealed how people lived before and after the colossal Toba volcanic eruption 74,000 years ago, according to Press Trust of India (PTI) on Tuesday.

The international and multidisciplinary research team, led by Oxford University in collaboration with Indian institutions, has uncovered what it calls 'Pompeii-like excavations' beneath the Toba ash.

The seven-year project examines the environment that humans lived in, their stone tools, as well as the plants and animal bones of the time.

"This suggests that human populations were present in India prior to 74,000 years ago, or about 15,000 years earlier than expected based on some genetic clocks," said project director Michael Petraglia, Senior Research Fellow in the School of Archaeology at the University of Oxford.

The team has concluded that many forms of life survived the super-eruption, contrary to other research which has suggested significant animal extinctions and genetic bottlenecks.

According to the team, a potentially ground-breaking implication of the new work is that the species responsible for making the stone tools in India was Homo sapiens.

Stone tool analysis has revealed that the artefacts consist of cores and flakes, which are classified in India as Middle Palaeolithic and are similar to those made by modern humans in Africa.

"Though we are still searching for human fossils to definitively prove the case, we are encouraged by the technological similarities.

An area of widespread speculation about the Toba super-eruption is that it nearly drove humanity to extinction.

The fact that the Middle Palaeolithic tools of similar styles are found right before and after the Toba super-eruption, suggests that the people who survived the eruption were the same populations, using the same kinds of tools, says Petraglia.

The research agrees with evidence that other human ancestors, such as the Neanderthals in Europe and the small brained Hobbits in Southeastern Asia, continued to survive well after Toba.

Although some scholars have speculated that the Toba volcano led to severe and wholesale environmental destruction, the Oxford-led research in India suggests that a mosaic of ecological settings was present, and some areas experienced a relatively rapid recovery after the volcanic event.

The team has not discovered much bone in Toba ash sites, but in the Billasurgam cave complex in Kurnool, Andhra Pradesh, the researchers have found deposits which they believe range from at least 100,000 years ago to the present.

They contain a wealth of animal bones such as wild cattle, carnivores and monkeys.

They have also identified plant materials in the Toba ash sites and caves, yielding important information about the impact of the Toba super-eruption on the ecological settings.

-- BERNAMA

Galapagos Volcano Erupting

Oh goddess! One of the ladies from the investment club is headed off for a Galapagos adventure next month - and here is this volcano erupting its head off on what I understand to be one of the larger of the islands (?) The eruptions started a week or two ago, and have been happening off and on since then. I emailed G about a news reports I saw some time last week. At the time, we joked about hoping her mother didn't find out! But the eruptions haven't ceased - drat! G, I do hope your long-awaited, once-in-a-lifetime tour won't be unduly affected. Here's the latest: From physorg.com Volcanic eruption takes toll on Galapagos wildlife April 16th, 2009 Image: Aerial handout photo released by the Galapagos National Park (PNG) on April 12, 2009 of the eruption of the La Cumbre volcano in Fernandina island, Galapagos, Ecuador. A volcanic eruption over the weekend has taken a toll on the wildlife of the ecologically-fragile Galapagos Islands, causing the deaths of numerous fish and various sea lions, said officials on Thursday. *************************************************************************** Not exactly what I'd want to see during a once-in-a-lifetime trip: dead animals floating on the ocean. Oh my.

Volcanic Eruptions Caused Climate Disruption

We've published several articles about this subject in Random Round-up at Goddesschess. It's a topic I find fascinating, especially through analyzing ice cores. This is from the National Geographic: Ancient Global Dimming Linked to Volcanic Eruption Ker Thanfor National Geographic News March 19, 2008 A "dry fog" that muted the sun's rays in A.D. 536 and plunged half the world into a famine-inducing chill was triggered by the eruption of a supervolcano, a new study says. The cause of the sixth-century global dimming has long been a matter of debate, but a team of international researchers recently discovered acidic sulphate molecules, which are signs of an eruption, in Greenland ice. This is the first physical evidence for the A.D. 536 event, which according to ancient texts from Mesoamerica, Europe, and Asia brought on a cold darkness that withered crops, sparked wars, and helped spread pestilence. Scientists had suspected the dry fog was caused by a volcanic eruption or a comet strike, but searches had failed to uncover evidence for either catastrophe—until now. "There is no need at the moment to invoke a large-scale extraterrestrial event as the cause, because the evidence is conclusive enough to say that it is certainly consistent with it being a large volcano," said study team member Keith Briffa of the University of East Anglia in the United Kingdom. The discovery is detailed in a recent issue of the journal Geophysical Research Letters. Global Ashfall Tests show the Greenland sulphate molecules were deposited sometime between A.D. 533 and 536. This date correlates well with a sulphate peak found in an Antarctic ice core. The team suspects the eruption occurred near the Equator, since its ash fell on both ends of the globe. The Greenland evidence is also consistent with tree-ring data from around the Northern Hemisphere that show reduced growth rates lasting more than a decade starting in A.D. 536. Curiously, the eruption's cooling effect did not extend to the southern hemisphere, the scientists say. Together, the tree-ring and acid evidence suggest the sixth-century eruption was even bigger than Indonesia's Mount Tambora eruption of 1815, which also dimmed the sun. Ken Wohletz, a volcanologist at Los Alamos National Laboratory in New Mexico, said that while the new evidence strongly supports a large volcanic eruption, a space impact can't be ruled out yet. "Over two-thirds of Earth's surface is covered with water, and because erosion so quickly wipes away evidence of impacts, the knowledge of when large-scale impacts have occurred in the past is still very incomplete," said Wohletz, who was not involved in the study. To cement their case, volcano advocates will need to find ash layers deposited by the blast, Wohletz said. William Ryan, an oceanographer at Columbia University's Lamont-Doherty Earth Observatory in New York, believes it is only a matter of time until ash layers are found. "I suspect we haven't searched adequately, but this paper will start a hunt," Ryan said. Indelible Mark According to written records, the dry fog lingered for just over a year—leaving an indelible mark on human history. Chinese historians recorded famine events and summer frosts for years after the event. It was also around this time that a band of Mongolian nomads called the Avars migrated westward toward Europe, where they would eventually establish an empire. The group may have left home when grasslands that their horses grazed on withered under the darkened skies, historians say. More controversially, some historians claim that drought caused by the fog contributed to the decline of the Mesoamerican city of Teotihuacan. (Related story: "New Digs Decoding Mexico's Pyramids of Fire'" [October 21, 2005].) The spread of bubonic plague throughout Europe and the Middle East, the rise of Islam, and even the fall of the Roman Empire have also been controversially tied to the event. Still Vulnerable If a similar volcanic eruption were to occur today, the effects could be just as devastating, experts say. The reduced sunlight and ashfall would affect agriculture worldwide, and the thick veil of dust and ash could cripple transportation and communication systems. "Most aircraft cannot fly in [volcanic] dust clouds," Los Alamos's Wohletz said. "And these dust clouds have a large electrostatic potential that disrupts radio communication." "And these dust clouds have a large electrostatic potential that disrupts radio communication." To make matters worse, there is practically nothing humans can do to prevent such a catastrophe from happening again—or to lessen its effects. "In today's society, we're no less independent of nature than humankind has ever been," Wohletz said. "In fact, we might even be more dependent on it."