Glacial Lake Missoula Flood – Longer Video

Glacial Lake Missoula Flood – Longer Video

Glacial Lake Missoula was bigger than all five Great Lakes put together. The huge lake, created by 45-mile wide tongue of ice known as the Purcell Lobe,  had a surface area of more than 3,000 square miles. When the ice dam collapsed, the ensuing flood raced across the landscape at several hundred miles an hour, draining the lake in just a matter of days.

As the flood rolled down the Columbia River it reached the Wallula Gap in southern Washington, which created a bottleneck. As the flood squeezed through the bottleneck, water levels rose to 800 feet and backed up, temporarily forming Lake Lewis in the Pasco Basin behind it. The flood eventually dropped ice-rafted boulders as far south as the Willamette Valley in Oregon.

Wallula Gap – Copyright Robert W Felix

When I originally read the accounts of the flood and the bottleneck created by the Wallula Gap, I pictured a very narrow passageway. However, when I actually visited the area, I discovered that the Wallula Gap is 1.2 miles (2 km) wide, not exactly the constricted channel that I had envisioned.

This video was originally published by Nick Zentner on Jun 14, 2015. It shows evidence for the lake including strandlines above the city of Missoula, Montana, along with giant current ripples at Camas Prairie and striking rhythmites along Interstate 90 at Nine Mile Road near Missoula.

Nick Zentner is the science outreach and education coordinator for the Department of Geological Sciences at Central Washington University. He has produced more than 40 short videos about Central Washington geology.

I’ll be posting more fascinating episodes of “Nick on the Rocks” in the days to come.

18 thoughts on “Glacial Lake Missoula Flood – Longer Video

  1. Nick on the rocks is good stuff. I have seen a number of his video’s on U Tube and they are interesting and informative. For old Geologists or up and coming new wanna be Geologists or anyone who has an interest in rocks, minerals or gemstones. Good pick as an addition to this website. Five stars!


  2. Abnormal snowfall brought to the capital of Russia more than 20% of monthly rainfall
    The air temperature will reach about 11 degrees Celsius.
    Before that, the NSO reported that on May 2 in the capital of Russia a new temperature record was registered. Long frosts have been registered in the capital for almost a week.
    Over the past day in the capital fell 11 mm of precipitation, which is 21.5% of the monthly rate.
    According to preliminary information from meteorologists, on Thursday evening, May 11, 11 millimeters of precipitation fell in the capital, which is a record for the entire region.
    “In the suburbs the coldest areas were Volokolamsky and Klin, and the warmest Serpukhovskaya and Kolomna.”
    In Klin and Dmitrov on May 10, the snow cover was restored three or four centimeters high, added on the site.
    http: //

    It became known when in Ukhta snow will stop and rains begin
    Warmth only from May 18
    Until the middle of next week it will be cold, it will only warm from Thursday, weather forecasters say.

    According to the forecasts of the Central Hydrometeorological Service, until Thursday, May 18, in Ukhta the cold weather will last. The deviation from the norm is 4-6 degrees. Until the middle of the week, the weather in the republic will remain cold.
    According to the forecast of the Central Hydrometeorological Service of Komi, the temperature deviation towards the cold will be on average 4-6C. In the night, the temperature will drop to -2 … -7С, in the extreme north-eastern regions to -10 … -15С. In the afternoon the air will warm up to +5 … + 7С. The snow will go places, mostly in the south and north of the Komi. Sharp warming will begin on Thursday. The warm air from Russia will start to flow. And in Ukhta it will warm up to +15 … + 18С. There will be small rains everywhere.

  3. These ice age floods into the pacific ocean; would they have had much effect on the salinity of the pacific?

  4. That was very interesting, I’d seen something about this but had been unable to find any worthwhile information.

    Thank you

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