- LOS ALAMOS, NM - The
beginning
of the Dark Ages may have been literal, as well as figurative, as the
result
of a massive volcanic eruption in the 6th century, according to a
volcanologist
at the Department of Energy's Los Alamos National Laboratory.
-
- Ken Wohletz said an eruption in the Indonesian
archipelago
could have produced a 150-meter-thick cloud layer over the entire Earth,
triggering a chain of climatic, agricultural, political and social changes
that ushered in the Dark Ages.
-
- Evidence supporting the catastrophe includes tree-ring
and ice-core measurements, indications of a huge underwater caldera, and
ash and pumice in the same area, said Wohletz, who discusses his work
modeling
such an eruption today (Dec. 17) at the fall meeting of the American
Geophysical
Union.
-
- The 6th century was a turbulent, unsettling period in
human history. The Roman Empire began to fall; nomads of central Asia
migrated
to Europe and the Near East; civilizations in Persia, Indonesia and South
America collapsed; major religions experienced considerable change as
natural
events were viewed as omens.
-
- Many of these social transformations resulted from
widespread
crop failures and the explosion of plague around the globe, which in turn
were caused by major climatic changes, Wohletz said. Beginning in about
the year 535, according to historical and archeological records, the
weather
was colder and drier, sunlight diminished, snow fell in summer and regions
of persistent drought suffered floods.
-
- Wohletz was a resource for a book postulating that the
climate changes resulted from a huge volcanic eruption. The book,
"Catastrophe:
A Quest for the Origins of the Modern World" by David Keys, was
published
earlier this year.
-
- Wohletz said he worked with Keys to try to identify a
volcano that could produce such dramatic climate change. "We came
up with an eruption that would certainly be the largest in recorded
history,
some four or five times bigger than the (1815) eruption of Tambora, which
is usually considered the biggest eruption in the past few millennia,"
he said.
-
- Such an explosion, he said, would eject some 200 cubic
kilometers of material, and one-third to one-half of it would be lofted
into the stratosphere, where it would remain suspended for months to years
while being carried around the globe.
-
- "It would have produced enough dust and water vapor
(in the form of ice crystals) to form a cloud layer 150 meters thick over
the entire globe, and that's a conservative estimate," he said, adding
that a cloud of particles that thick may have diminished the transmission
of sunlight by as much as 50 percent.
-
- Wohletz said tree-ring data collected around the world
and ice-core measurements in Greenland and Antarctica support the
possibility
of a huge eruption in the 6th century. Ocean depth measurements between
Sumatra and Java - where Krakatoa exploded in a well known 1883 eruption
- indicate the presence of a caldera up to 50 kilometers in diameter, and
a recent survey uncovered evidence of ash and pumice layers formed in the
area during the appropriate time frame.
-
- Under a likely scenario, a large volcano, which Wohletz
calls proto-Krakatoa, connected the islands of Sumatra and Java. When it
erupted and then subsided, it created the Sundra Strait and left a ring
of smaller volcanoes, including the present day Krakatoa. The ash, dust
and water vapor blown into the stratosphere would disperse across both
the Northern and Southern Hemispheres.
-
- "This volcano would have had the potential to be
a major player in destabilizing the climate around the world," he
said. "An eruption that could produce a caldera 50 kilometers across
would have been big enough."
-
- Although definitive evidence for such a catastrophic
eruption has not been discovered, the possibility deserves a full-scale
field study, Wohletz said, in part because of the potential impact on the
world if another such catastrophe happens.
-
- "(Key's book) is the first detailed account of how
closely humanity is linked to the natural world," he said. "If
the natural world goes through some large upheaval, we'll all be
affected."
-
- Los Alamos National Laboratory is operated by the
University
of California for the U.S. Department of Energy.
-
-
- Editor's Note: The original news release can be found
here.
Note: This story has been adapted from a news release issued by Los Alamos
National Laboratory for journalists and other members of the public.
If you wish to quote from any part of this story, please credit Los Alamos
National Laboratory as the original source. You may also wish to include
the following link in any citation: Link
-
-
-
- MainPage
http://www.rense.com
-
-
-
- This
Site Served by TheHostPros
|