The Lake Missoula Flood occurred at the peak of the Ice Age that occurred shortly after the Global Flood, developing over a period of approximately 500 years and melting over the next 200 years, lasting a total of about 700 years. A proglacial lake1 in the valleys of western Montana, USA, broke through its ice dam and drained in about 48 hours (Figure 1).2
The flood rushed through eastern Washington, forming a series of small lakes south of Grand Coulee, the last and southern most one being Soap Lake.
The flood ran down the current path of the Columbia River at up to 115 ft./sec. (35 m./sec.) with a discharge about 15 times the combined flow of all the rivers of the world.3
Glacial Lake Missoula had a volume of about 528 cubic miles (2,200 cu. km.) based on the many shorelines observed in the western mountain valleys of Montana (Figure 2).
It was held back by an ice dam around 2,300 ft. (700 m.) or more thick. The Lake Missoula Flood is believed by geologists to have carved out the Grand Coulee and Dry Falls in north central Washington.4 The Grand Coulee is a gorge about 50 miles (80 km) long and up to 1,000 ft. (300 m) deep. Dry Falls sits at the head of a gorge about 328 ft. (100 m) deep and 3 miles (5 km) long about midway in the Grand Coulee.
A recent observation of a catastrophic flood (jökulhlaup) in Iceland provides further support for the one gigantic Lake Missoula Flood.5 Water from snow, melted by a volcanic eruption under a glacier, burst from under the ice on November 5, 1996. (Figure 3.)
The peak discharge was 1,600,000 cu. ft./sec (45,000 cu. m./sec), which was only 0.2 % of the peak discharge of the Lake Missoula Flood. Iceland’s jökulhlaup lasted about 36 hours. Besides crossbeds (in geology, the sedimentary structures known as cross-bedding refer to near-horizontal units that are internally composed of inclined layers) in the slackwater bay, planar (made up of flat planes) beds dipping at a low angle formed many normally graded rhythmites of fine gravel and coarse sand. (A rhythmite consists of layers of sediment or sedimentary rock which are laid down with an obvious periodicity and regularity.) Two hundred planar rhythmites and 100 prograding (the growth of a river delta) rhythmites formed a section 50 ft. (15 m) thick in just 17 hours. That is one rhythmite every 3 to 4 minutes! Moreover, large rip-up clasts (rock fragments or grains resulting from the breakdown of larger rocks) of bedded strata composed of stratified sand and gravel up to 10 ft. (3 m) in diameter were embedded within the rhythmites.
If the small Iceland flood can produce 50 ft. (15 m) of rhythmites in a short time, the Lake Missoula Flood could certainly form rhythmites along the edge of its flow path with a maximum thickness at Burlingame Canyon of about 165 ft. (50 m). The rhythmites in Iceland were deposited by repeated turbulent flow pulses, which supports the multiple rhythmite conclusion of Shaw et al7 in the Lake Missoula Flood. Since the Iceland flood was actually observed and carefully documented all along its progression, the same processes, applied to the Lake Missoula flood, would validate the feasibility of the Lake Missoula flood producing similar results on a much larger scale but in an equivalent drainage time of around 48 hours.
The Lake Missoula Flood, as well as the much smaller Icelandic flood, may provide insight into the Global Flood. For instance, landforms produced by the Lake Missoula Flood may provide an analogue for landforms produced by the Global Flood. Secondly, the rhythmites of the Icelandic and Lake Missoula Floods may provide insight on how turbulent flow pulses can lay down sedimentary layers rapidly. Third, the rapid erosion of approximately 50 cubic miles of loess (sediment formed by the accumulation of wind-blown silt) and basalt from the Lake Missoula Flood can help us better appreciate the catastrophic erosion processes of the Global Flood.
In order to claim credit for this cache please email the cache owner (do not post) answers to the following questions.
1. How long did it take for Lake Missoula to drain?
2. What process could lay down sedimentary layers quickly?
3. How often did the Iceland flood form rhythmites?
4. From the posted final coordinates face east and count the number of rhythmites between the arrows in the photo below.
Please feel free to post pictures as long as they do not reveal answers to any of the questions.
Courtesy of Michael J Oard. Michael serves on the board of the Creation Research Society, USA and lives in Montana.
References
1. A lake immediately in front of a glacier, or just outside the limits of an ice sheet.
2. Allen, J.E. and Burns, M., with Sargent, S.C., Cataclysms on the Columbia, Timber Press, Portland, Oregon, 1986.
3. O’Connor, J.E. and Baker, V.R., Magnitudes and implications of peak discharges from glacial Lake Missoula, Geological Society of America Bulletin 104:267–279, 1992.
4. Weis, P.I. and Newman, WlL., The Channeled Scablands of Eastern Washington—The Geologic Story of the Spokane Flood, 2nd Ed., Eastern Washington University Press, Cheney, Washington, 1989
5. Oard, m.j., An Ice Age Caused by the Genesis Flood, Institute for Creation Research, El Cajon, California, 1990.
6. Snelling A.A.
7. Iceland's recent 'mega-flood': an illustration of the power of Noah's Flood, Creation 21(3):46-48, 1999.