Explosive Events and Explosive Events and Climate ChangeClimate Change

More frequent events than More frequent events than people realizepeople realize

The 535/6 AD event

Remains controversial but there is a lot of consistent evidence for a large volcanic explosion

From Greece: "during this year a most dread portent took place. For the sun gave forth its light without brightness ... and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear."

England: The sun became dim ... for nearly the whole year ... so that the fruits were killed at an unseasonable time

Syria: The sun became dark and its darkness lasted for eighteen months. Each day it shone for about four hours, and still this light was only a feeble shadow ... the fruits did not ripen and the wine tasted like sour grapes."

Europe

"The sun ... seems to have lost its wonted light, and appears of a bluish colour. We marvel to see no shadows of our bodies at noon, to feel the mighty vigour of the sun's heat wasted into feebleness, and the phenomena which accompany an eclipse prolonged through almost a whole year. We have had ... a summer without heat ... the crops have been chilled by north winds ... the rain is denied ..."

Now tree-ring data, published by Professor Mike Baillie of Queens University of Belfast, has brought catastrophes almost into modern times. The tree rings show that in the mid 530s -- just about the time civilisation on Earth suffered a sharp setback -- there was a sudden decline in the rate of tree growth which lasted about 15 years. Clearly, something dramatic had happened.

“In China in 536 there was drought and famine and “yellow dust rained like snow… The crops were ruined the following year by snow in August.””

“Starting in the 530s, a horrific 32-year long drought devastated parts of South America.”

Antarctica and Greenland Evidence Scientists, again using ice-cores, discovered

evidence of a truly massive volcanic eruption.  The ice-core material revealed that acid snow had cascaded down on the Antarctic for at least four years running….(This) occurred sometime  between 490 and 540.”

These explosive eruptions will generate a lot of acid rain due to the high sulfur content of the emissions

1300 year later account campfire stories passed down?

There was a furious shaking of the earth, total darkness, thunder and lightning… Then came a furious gale together with torrential rain and a

deadly storm darkened the entire world.”

The chronicle – known as the “Pustaka Raja Purwa (‘The book of Ancient Kings’) … claims that the eruption was so massive that …. “After the water subsided the mountain (which had burst into pieces) and the

surrounding land became sea and the (single) island (of Java/Sumatra) divided into two parts.  This (event) was the origin of the separation of

Sumatra and Java.” “

World wide trigger?World wide trigger?

http://forums.civfanatics.com/archivehttp://forums.civfanatics.com/archive/index.php/t-116880.html/index.php/t-116880.html

Most of this is speculation but the Most of this is speculation but the evidence for abrupt climate change evidence for abrupt climate change is pretty soundis pretty sound

Speculation is that Kratatau was the Speculation is that Kratatau was the event:event:535 Krakatau Super Eruption535 Krakatau Super Eruption

The Alternative SiteThe Alternative Site• A violent eruption occurred at Ilopango in the 5th century

AD. erupted more than 70 cu km of tephra, produced major ash fall and large pyroclastic flows that covered 10,000 sq km under 50 cm or more of pumice and ash. Pyroclastic flows and ash fall devastated an area of up to 100 km radius around the volcano.

• The eruption severely impacted the Mayan culture living in the highlands of El Salvador. The eruption killed thousands, destroyed settlements and sent many to flee to the lowland areas in Guatemala and Belize. It ended the Mayan presence in the highlands.

• A major trade route controlled by the Mayas was abandoned and power shifted to Tikal.

Major Hazards in the Area:Major Hazards in the Area:

Where you gonna run?Where you gonna run?

84,000 years ago: Ash Fall out Density 84,000 years ago: Ash Fall out Density ContoursContours

Explosive Remnants. Santorini

Coatepeque Caldera in El Coatepeque Caldera in El SalvadorSalvador

GalapagosGalapagos

Pinatubo (1991)Pinatubo (1991)

Ngorongoro CraterNgorongoro Crater- Africa- Africa

Cape Verde Islands (1995)Cape Verde Islands (1995)

Ethiopia 2008Ethiopia 2008

Yellowstone hot spot calderas

Valles Caldera – NM –with rhyolite dome

Antarctica – similar to Santorini except no Minoans there …

Silverthorne, BC – use your imagination

Near RomeNear Rome

San Pedro, GuatemalaSan Pedro, Guatemala

Biggest known Calderas