What caused the Scablands?
Geology questionsDuring the last ice age, 18,000 to 13,000 years ago, the landscape of eastern Washington was repeatedly scoured by massive floods. They carved canyons, cut waterfalls, and sculpted a terrain of braided waterways today known as the Channeled Scablands.
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How was the Scablands formed?
The channeled scabland was created where the Ice Age floods accelerated across the tilted surface of the Palouse slope, causing massive erosion. Much of the eroded sediment was carried all the way to the Pacific Ocean.
What caused the Missoula floods?
These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon.
What caused the Washington flood?
That storm was fueled by tropical moisture from the remnants of western Pacific Ocean Typhoons Hagibis and Mitag. Heavy, even record, rainfall combined with the rapidly melting low elevation snow to produce record flooding in western Washington. The 6 hour rainfall amounts were near 100-year event level.
What carried the erratics into Scablands?
The Scablands are littered with large boulders called glacial erratics that rafted on glaciers and were deposited by the glacial outburst flooding. The lithology of erratics usually does not match the rock type that surrounds it, as they are often carried very far from their origin.
How did the giant boulders get to the Scablands?
And as chunks of ice from the original glacier were carried huge distances by the floodwaters, the boulders they contained within were randomly flung aside. When the flood waters receded and the icebergs melted they would reappear scattered all over the Scablands.
Who proposed Scablands rapidly formed?
J Harlen Bretz was a geologist who launched one of the great controversies of modern science by arguing, in the 1920s, that the deep canyons and pockmarked buttes of the arid “scablands” of Eastern Washington had been created by a sudden, catastrophic flood — not, as most of his peers believed, by eons of gradual …
Where are the Scablands located?
The Channeled Scablands extend from the area around Spokane, west to the Columbia River near Vantage and southwest to the Snake River near Pasco. They are known as the “Channeled Scablands” because they are crisscrossed by long channels cut into the bedrock, called coulees.
What formed Lake Missoula?
Glacial Lake Missoula formed as the Cordilleran Ice Sheet dammed the Clark Fork River just as it entered Idaho. The rising water behind the glacial dam weakened it until water burst through in a catastrophic flood that raced across Idaho, Oregon, and Washington toward the Pacific Ocean.
Was Missoula a lake?
Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago.
When did Lake Missoula drain?
A little after 19,000 years ago, water in Glacial Lake Missoula ruptured the ice dam, and the collected water went rushing downstream at speeds reaching 100 km/hr. Peak discharge in the Spokane Valley has been estimated at 17 +/- 3 million cubic meters per second, and drainage of the lake took several days.
When did Lake Missoula flood?
18,000 to 12,000 years ago
During the last Ice Age (18,000 to 12,000 years ago), and in multiple previous Ice Ages, cataclysmic floods inundated portions of the Pacific Northwest from Glacial Lake Missoula, pluvial Lake Bonneville, and perhaps from subglacial outbursts.
What did Lake Missoula look like?
The ice dam was over 2000 feet tall. Glacial Lake Missoula was as big as Lakes Erie and Ontario combined. The flood waters ran with the force equal to 60 Amazon Rivers. Car-sized boulders embedded in ice floated some 500 miles; they can still be seen today!
Who discovered Lake Missoula?
J Harlen Bretz
| Harley “J Harlen” Bretz | |
|---|---|
| Alma mater | Albion College, AB 1905 University of Chicago, PhD geology 1913 |
| Known for | Missoula Floods hypothesis, overturned uniformitarianism |
| Awards | Penrose Medal, 1979 |
| Scientific career | |
How much water is emptied from Lake Missoula?
It is estimated that the maximum rate of flow was equal to 386 million cubic feet per second. At that rate, the lake probably drained in a few days.
Does the Clark Fork River flood?
Flooding from the Clark Fork River is impacting the Orchard Homes residential area. Flood waters are now flooding Tower Street, Kehrwald Drive and Channel Drive with 10 to 15 homes being flooded.
Flood Categories (in feet)
| Major Flood Stage: | 13 |
|---|---|
| Flood Stage: | 7.5 |
| Action Stage: | 7 |
| Low Stage (in feet): | -9999 |
How fast does the Clark Fork River flow?
Clark Fork River
| Clark Fork Original name given by Lewis and Clark expedition: Clark’s River | |
|---|---|
| Discharge | |
| • location | Whitehorse Rapids near Cabinet, ID |
| • average | 21,930 cu ft/s (621 m3/s) |
| • minimum | 762 cu ft/s (21.6 m3/s) |
Where is the lower Clark Fork Region?
The Lower Clark Fork Watershed (Hydologic Unit Code: 17010213) is the downstream-most portion of the Clark Fork Basin, composed of all the area (2,336 sq miles) draining into the Clark Fork River between its confluence with the Flathead River downstream to Lake Pend Oreille (see map above).
What river goes thru Missoula?
The Clark Fork River
The Clark Fork River runs about 310 miles long and is the largest river by volume in Montana. The Clark Fork River cuts straight through the heart of Missoula.
Can you wade the Clark Fork River?
From the meandering meadow headwaters to the massive watershed moving into Idaho, the Clark Fork truly has something for every fly fisherman. And as you wade or float this western Montana river, think about how tough Mother Nature really is.