ENTRY TASK Give a piece of physical evidence that supports the existence of a mega flood.

CHANNELED SCABLANDS

WHAT DID WE LEARN FROM THE VIDEO? When were the scablands first recognized? Who developed the theory of a mega flood? What were the flaws with his theory? Where did the water come from? The water rushed from ______ to _____?

INFORMATION AND MATERIALS FROM GLACIALLAKEMISSOULA.ORG EVIDENCE OF A MEGA FLOOD

LAND DEFORMATION What is land deformation? The changing of the earth’s crust.

WHAT CAUSES LAND DEFORMATION? Volcanoes Earthquakes Flood Weathering and Erosion (wind, water, ice, gravity)

GRADUALISM Charles Darwin is credited with defining geological gradualism. He stated that large changes are a result of small changes adding up over time. This theory stemmed from his theory of evolution. Small changes in genetics will show large changes in a species over time.

WHAT DARWIN NOTICED He witnessed an eruption on Mount Osorno. He survived an earthquake in Valdivia. He made observations on weathering of rocks and the crystallization of lava.

CORAL REEF THEORY He suggested that corals grow around islands, but over long periods of time the sea floor can subside. The coral would continue to grow whereas the island would be washed away, so leaving the coral reef alone to be observed now. Darwin’s theory was instantly accepted by the geological community. -

VOLCANIC ISLAND THEORY volcanoes are usually formed when lava repeatedly erupts so layers of volcanic rock are laid down successively building up the cone. At the time, many geologists believed a volcano grew up because of pressure from below and the crater then subsided. Darwin’s idea was right. Darwin almost struck on a much bigger idea, his observations led him to believe the earth’s crust was moving, rising in some places and subsiding in others.

The Autobiography of Charles Darwin by Charles Darwin (Edited by Francis Darwin), The Thinker's Library : 1929 Charles Darwin, Geologist by Sandra Herbert, Cornell University Press : 2005 Darwin by John van Wyhe, Andre Deutsch : 2009 Darwin by Adrian Desmond & James Moore, Penguin : 1991 Journal of Researches by Charles Darwin, 1839 (any edition) On the Origin of Species by Charles Darwin, 1859 (any reprint - 2nd edition preferable)

GLACIAL LAKE MISSOULA

The horizontal lines etched into the hillside are evidence that a prehistoric lake once filled the valley. The parallel lines represent the ancient shorelines of Glacial Lake Missoula. The highest known shorelines are found at an elevation of 4,200 feet. If the lake existed at this level today, the city of Missoula would sit beneath 950 feet of water.

CLARK FORK RIVER

When it burst through the ice dam and exploded downstream, the waters of Glacial Lake Missoula ran at a rate of 10 times the combined flow of all of the current rivers in the world! The fast draining waters left many features similar to features seen along creeks and rivers today, but on an exaggerated scale.

CAMAS PRAIRIE RIPPLES

In 1942, Geologist Joseph T. Pardee identified these unique parallel ridges found in the Camas Prairie as "giant" ripple marks. With an average height between feet these ripple marks would dwarf any ordinary ripple mark you might find on a beach or in a river today. The Camas Prairie ripple marks were formed as the deep and swift flowing water from Glacial Lake Missoula raced through the failed ice dam at speeds up to 50 miles per hour.

CHANNELED SCABLAND

The floodwaters from Glacial Lake Missoula moved through eastern Washington forever changing the landscape by stripping away topsoil, picking apart the bedrock, and carving an immense channel system into the land. This area, known as the Channeled Scablands, provided geologists with the first clues of the catastrophic nature of the Ice Age Floods.

POTHOLES

PALOUSE FALLS

DRY FALLS

During the Ice Age floods, water over 300 feet deep poured over the 350- foot cliffs of Dry Falls. At three miles wide, Dry Falls is five times the width of Niagara Falls.

FLOOD DEBRIS

After stripping away 200 feet of topsoil, the flood ripped away huge boulders from the underlying lava rock. These boulders were picked up and carried in the floods only to be stranded in fields and prairies when the floodwaters subsided.

TEMPORARY LAKES

By looking at flood sediments from Glacial Lake Missoula, geologists try to calculate the number floods and subsequent fillings of the glacial lake. Many layers of glacial lake sediments are found situated on top of one another; each layer represents a separate filling of the lake. The exact number of floods that occurred is still unknown, but evidence shows that it happened on possibly 40 different occasions.

COLUMBIA RIVER GORGE

The floods left a visual legacy that can be seen all along its path, though few places are as grand as the waterfalls of the Columbia River Gorge. The floodwaters did not create the Gorge, rather, they scoured and steepened its walls. Creek junctions with the Columbia were torn away, leaving the creeks to plunge over the lip of the newly cut gorge in a series of spectacular waterfalls.

ERRATIC

As glaciers scour the landscape, they pick up massive boulders and move them far from their point of origin. When the glacier that formed Glacial Lake Missoula's dam burst, uncountable boulders embedded in its ice were carried along with the floodwaters. As these ice blocks melted, the boulders dropped out of the flow. Today, boulders with origins in the mountains of Montana and British Columbia can be found along the flood paths as far away as Oregon's Willamette Valley.

WALLULA GAP This is a gap that prevented the great floods from heading directly to the Pacific ocean. Because the constriction at Wallula Gap was only 1 mile wide, the flood waters back-flooded into the Pasco Basin. Formed, for a short period of time, Lake Lewis.

ONTO THE PACIFIC

After racing through the Columbia River Gorge and backwashing into Oregon's Willamette Valley, the floodwaters ended its journey at the Pacific Ocean near Astoria, Oregon. New studies are revealing what became of the floods sediments as the waters mixed with the Ocean.