63. Climate history of North America
Younger Demise of Laurentide
Dryas Ice Sheet
20 16 12 8 4 0
THOUSANDS OF
YEARS AGO
Final drainage
of Lake Agassiz
LAST GLACIAL MODERN
MAXIMUM OBSERVATIONS
76. MAY 3
The river rose six feet last night perpendicularly, several tents are
now pitched upon the most elevated spots: terror is strongly depicted
on every countenance… David Jones Journal
77. MAY 5
On a point of the river above us, four horses and a barn were swept
off by the force of the ice and the ruins floated past us to–day on the
surface thereof… David Jones Journal
78. MAY 5
The force of [the ice] is inconceivable; the lo iest elm trees are
carried away like the most inconsiderable things. David Jones Journal
79. “
The forts now stand like a castle of romance in the midst of
an ocean of deep contending currents, the water extending
for at least a mile behind them, and they are thereby only
approachable by boats and canoes.”
Francis Heron
Hudson Bay Company, 1826
St.. George and Rannie, Canadian Water Resources Journal, 2003
85. “ RINGS
IN THE BRANCHES OF
SAWED TREES SHOW
THE NUMBER OF YEARS
AND, ACCORDING TO THEIR
THICKNESS,
THE YEARS WHICH WERE
MORE OR LESS
DRY. ”
Leonardo da Vinci
