People of the Nightland (North America's Forgotten Past)

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Authors: W. Michael Gear,Kathleen O'Neal Gear

BOOK: People of the Nightland (North America's Forgotten Past)
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Table of Contents
Title Page
Foreword
Prologue
One
- THE WINTER OF ICEBACKED MAMMOTHS …
Two
- FIVE WINTERS LATER: MOON OF THE MELTING SNOW
Three
- TWO WINTERS LATER—THE EQUINOX MOON
Four
Five
Six
Seven
Eight
Nine
Ten
Eleven
Darkness
Twelve
Thirteen
Fourteen
Fifteen
Sixteen
Seventeen
Eighteen
Nineteen
Twenty
Twenty-one
Twenty-two
Twenty-three
Exile
Twenty-four
Twenty-five
Twenty-six
Twenty-seven
Twenty-eight
The Destruction
Twenty-nine
Thirty
Thirty-one
Thirty-two
Thirty-three
Thirty-four
Confusion
Thirty-five
Thirty-six
Thirty-seven
Thirty-eight
Thirty-nine
Forty
Forty-one
Forty-two
Forty-three
Pain
Forty-four
Forty-five
Forty-six
Forty-seven
Forty-eight
Distress
Forty-nine
Fifty
Fifty-one
Fifty-two
Fifty-three
Dislocation
Fifty-four
Fifty-five
Fifty-six
Fifty-seven
Fifty-eight
Fifty-nine
Sixty
Sixty-one
Sixty-two
Sixty-three
Sixty-four
Sixty-five
Sixty-six
Sixty-seven
Sixty-eight
Sixty-nine
Seventy
Epilogue
Afterword
BY W. MICHAEL GEAR AND KATHLEEN O’NEAL GEAR FROM TOM DOHERTY ASSOCIATES - NORTH AMERICA’S FORGOTTEN PAST SERIES
Selected Bibliography
Copyright Page
To Pia, Nebi, Keeza, Wyatt, Slipper and Nononi,
Little Snowbear, Golden Boy, Little Blue, and Morgan,
our orphans,
for teaching us that the way to the Great Mystery is not
through singing or dancing, not through reading or praying …
it comes from giving life to those who need it.
 
All of you have given us life in abundance.
 
Mitakuye oyasin.
THE ICE GIANTS
F
or the most part, global warming is cyclical, as is global cooling. This discovery was first articulated by Serbian mathematician Milutin Milankovitch in 1930 when he published his classic work
Mathematical Climatology and the Astronomical Theory of Climate Change.
Milankovitch’s theory was relatively straightforward. He said that Ice Ages occurred when variations in the Earth’s orbit and axis caused the northern hemisphere to receive less sunshine in the summer, and that these short summers failed to melt the snow and ice that had accumulated on the continents during the winter. The result was that the growing white patches on the face of the Earth reflected sunlight away from the planet, causing it to cool, and as the white expanses grew each year, reflecting more and more sunlight, they triggered Ice Ages.
Milankovitch proposed three reasons for this process:
First, he said, every year the Earth’s orbit around the sun changed slightly. This cycle took about 100,000 years, but when the Earth was farthest from the sun, the planet naturally grew colder.
Second, he said the angle of the Earth’s axis was not constant. The tilt varied between twenty-two and twenty-four degrees. At its maximum
tilt, which occurred every 41,000 years, the North Pole received much less sunlight, which led to an accumulation of glacial ice.
Third, he noted that the Earth wobbled on its axis, toward and away from the sun over a span of 19,000 and 23,000 years. These small variations changed how much sunlight each hemisphere received.
As a result, Milankovitch predicted that Ice Ages would peak every 100,000 years and 41,000 years, and that the Earth would undergo small “blips” every 19,000 and 23,000 years.
Today, after countless scientific studies in paleoclimatology, we know that Milankovitch was right.
There
are
slow and regular variations in the Earth’s orbit and axis that result in Ice Ages—ten in the last million years.
The Pleistocene Ice Age is divided into three periods, Early, Middle, and Late. The Late Pleistocene began with a global warming episode called the Sangamonian, which lasted from about 135,000 years ago to around 115,000 years ago. That warm period was followed by an episode of glaciation called, in North America, the Wisconsin glaciation.
At the peak of this glacial episode, 20,000 years ago, ice covered most of Canada and extended south into the United States as far as Iowa and central Illinois. The largest glacier, the Laurentide ice sheet, was almost three miles thick over Hudson’s Bay. The immense weight of the glacier depressed the Earth’s crust more than 3,250 feet below its current elevation.
Glaciers are not static or “dead.” Each is a constantly churning ecosystem. The ice is banded with silt, sand, gravel, and rocks that have been scraped up from the Earth. The very weight of the ice makes it plastic, with the lower regions squeezing out at the sides. Water melting at the surface rushes down through fissures, boring a honeycomb of caves. Twenty thousand years ago most of this water flowed directly into the ocean down the Mississippi River drainage. Icebergs also calved into the Atlantic and along an extension of the Gulf of St. Lawrence, called the Champlain Sea by paleoclimatologists (Thunder Sea in
People of the Nightland
). The Champlain Sea, a body of saltwater, extended as far west as modern Hamilton, Ontario. Imagine seeing seals, walrus, and pilot whales in the water off Rochester, New York.
Then another global warming period began. These “interstadials,” or periods of ice retreat and rising ocean temperatures, generally occur for the same reasons that global cooling occurs—shifts in the
Earth’s orbit and axis. When the Earth moves closest to the sun in its orbit, the planet warms up. When the tilt of the axis reaches its minimum, summers are longer, glaciers melt, and air and ocean temperatures rise. Every system, however, experiences moments of chaos, episodes of “abrupt climate change,” that don’t obey these rules.
Starting 20,000 years ago, the Earth began to warm and the North American ice sheets began to melt. Everything was proceeding exactly as it should … until around 13,000 years ago.
The Younger Dryas Interval, a global cooling period that lasted from about 13,000 years ago to 11,650 years ago, is one of the most dramatic events in prehistory. Within a single decade, the Earth was knocked back into an Ice Age. The North Atlantic Deep Water Current, which warms Europe, stopped running, leaving the continent bitterly cold, and ocean levels rose a stunning eighty feet. The glaciers that had been in retreat for 7,000 years began advancing again.
The cause was simple: Meltwater from the Laurentide Ice Sheet was diverted from its main Mississippi River drainage to the Champlain Sea—today’s St. Lawrence River.
What caused this diversion is not so simple. By 13,000 years ago, a gigantic meltwater lake had formed over parts of Manitoba, North Dakota, Minnesota, and Wisconsin. Lake Agassiz, named after nineteenth-century Swiss geologist Louis Agassiz, covered over 80,000 square miles. It held more water than the total contained in all the modern world’s lakes. Beaches stretched from North Dakota northward to Manitoba. What is now Winnipeg was under 650 feet of water.
The Younger Dryas was kicked off when the water level in Lake Agassiz suddenly dropped by over 325 feet.
What caused the drop? One of the Earth’s greatest cataclysms—which we will discuss further in the Afterword of this book.
For now, let’s just say that human beings, people we call PaleoIndians, witnessed it, and, in a very real sense, it was the end of their world.

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