What it means is
that the Arctic was likely filled with massive ice sheets like those around
Antarctica that remained stable enough until quite recently. I have expected this and it is well to see it
confirmed.
My extended conjecture
regarding the Pleistocene Nonconformity includes two instances in which the
Crust shifted off its pole. The first
was a natural event allowing for rebalancing brought about by the buildup off
the ice. This appears to have occurred
around twenty thousand years ago and brought about immense changes in the
Arctic but not sufficient actually end the northern Ice Age. What it did do was provide proof of concept.
This then led to
the direct targeted event of 12900 years ago that shifted the crust correctly to
end the Ice Age. This was done with a precisely
target comet impact onto the Ice Cap.
To be an accident, it would have to be one in a billion shot making it
likely unique in this galaxy. That is
why I have no doubt that it was a planned event and how discovering that impact
event almost a decade ago forced me to completely rethink human history.
Science meanwhile
is busily catching up by digging up the evidence.
Traces Of
Immense Prehistoric Arctic Ice Sheets During The Pleistocene
Geologists and geophysicists have discovered traces
of large ice sheets from the Pleistocene on a seamount off the north-eastern
coast of Russia, confirming for the first time that within the past 800,000
years in the course of ice ages, ice sheets more than a kilometer thick also
formed in the Arctic Ocean.
This makes it possible to write an accurate climate history for this part of the Arctic. They had discovered the first signs of conspicuous scour marks and sediment deposits on the ocean floor north of Wrangle Island (Russia) on a Polarstern expedition in 2008 but they were unable to gather extensive proof until last year, during an Arctic expedition on the South Korean research vessel Araon. "After we had analysed the bathymetric and seismic data from our first voyage, we knew exactly where we needed to search and survey the ocean floor with the swath sonar of the Araon on the second expedition," said Frank Niessen of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), first author of the study.
The result of this research is a topographic map of
the Arlis Plateau, a seamount on which deep, parallel-running furrows can be
discerned on the upper plateau and the sides – and over an area of 2500 square
kilometers and to an ocean depth of 1200 meters. "We knew of such scour
marks from places like the Antarctic and Greenland. They arise when large ice
sheets become grounded on the ocean floor and then scrape over the ground like
a plane with dozens of blades as they flow.
"The remarkable feature of our new map is that it indicates very accurately right off that there were four or more generations of ice masses, which in the past 800,000 years moved from the East Siberian Sea in a north-easterly direction far into the deep Artic Ocean," says Niessen.
These new findings overturn the traditional textbook
view of the history of Arctic glaciations.
"Previously, many scientists were convinced that mega-glaciations always took place on the continents – a fact that has also been proven for Greenland, North America, and Scandinavia. However, it was assumed that the continental shelf region of North-eastern Siberia became exposed in these ice ages and turned into a vast polar desert in which there was not enough snow to enable a thick ice shield to form over the years. Our work now shows that the opposite was true. With the exception of the last ice age 21,000 years ago, ice sheets formed repeatedly in the shallow areas of the Arctic Ocean. These sheets were at least 1200 meters thick and presumably covered an area as large as Scandinavia," says Niessen.
The AWI scientists still cannot say for certain,
however, under what climate conditions these ice sheets formed and when exactly
they left their marks on the bottom of the Arctic Ocean. "We theorize that
the East Siberian ice sheets arose during various ice ages when the average
global temperature was around five to eight degrees Celsius cooler than what it
is today. But evidently this relatively minor temperature difference was often
sufficient to allow initially thin ocean ice to grow into an immense ice cap.
An example that shows just how sensitively the Arctic reacts to changes in the
global climate system," says the geologist.
In a next step, the AWI researchers now want to try
collecting soil samples from deeper layers of the ocean floor with a sediment
core drill and thus learn more details about the prehistoric ice sheets.
"Our long-term goal is to reconstruct the exact chronology of the
glaciations so that with the aid of the known temperature and ice data, the ice
sheets can be modeled. On the basis of the models, we then hope to learn what
climate conditions prevailed in Eastern Siberia during the ice ages and how,
for example, the moisture distribution in the region evolved during the ice
ages," says Frank Niessen. This knowledge should then help predict
possible changes in the Arctic as a consequence of climate change more
accurately.
Frank Niessen and his colleagues are anticipating a
great number of surprising discoveries in the Arctic Ocean in the future.
"As the Arctic Ocean sea-ice cover continues to shrink, more formerly
unexplored ocean area becomes accessible. Today less than ten percent of the
Arctic Ocean floor has been surveyed as thoroughly as the Arlis Plateau,"
says the AWI geologist. And this study would not have succeeded were it not for
the outstanding cooperation of the AWI scientists with researchers of the South
Korean Polar Research Institute KOPRI. "We complemented each other
perfectly in this research. Our South Korean colleagues had the expedition and
ship time, we knew the coordinates of the area in which we now found the
evidence of the mega-glaciations," says Frank Niessen.
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