Map of the Missoula Flood
Missoula Flood Wine Poster
This one-of-a-kind, limited edition wine poster is available only from Pacific Rim. The Missoula Floods – which occurred during the last Ice Age 15,000 years ago – are widely recognized as the most catastrophic geologic event in the Earth’s history. The floods forever changed the region’s landscape and birthed soils that are uniquely exceptional for growing world-class grapes (most notably, Riesling). Beautifully illustrated in great detail by world-renown artist, Alex Gross, the map features:
- The course of the floods’ torrents from the massive Missoula Dam through the Northwest states out to the Pacific Ocean
- Northwest wine appellations
- Vignettes providing the historic and geographic impact of the floods
- A Northwest soil cross-section
Printed on premium paper, the poster will enhance any home, office or cellar with beauty and drama. You’ve truly not seen a wine map quite like this one.
Map Dimensions: 16" H 29" W
The last glacial age between 15,000 and 13,000 years ago.
Ice dam formed by a tongue of ice blocking Clark Fork River in Montana creating Glacial Lake Missoula with a high water mark of 1,280 meters, near Missoula, MT.
As the depth of the water in Lake Missoula increased, the pressure at the bottom of the ice dam increased enough to lower the freezing point of water below the temperature of the ice forming the dam. This allowed liquid water to seep into minuscule cracks present in the ice dam. Over a period of time, the friction from water flowing through these cracks generated enough heat to melt the ice walls and enlarge the cracks. This allowed more water to flow through the cracks, generating more heat, allowing even more water to flow through the cracks. This feedback cycle eventually weakened the ice dam so much that it could no longer support the pressure of the water behind it, and it failed catastrophically. 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. After the rupture, the ice would reform, creating Glacial Lake Missoula again. Geologists estimate that the cycle of flooding and reformation of the lake lasted an average of 55 years and that the floods occurred several times over the 2,000 year period.
The water would come down running at 60 mph – for a flow of about 10 cubic miles per hour (that is about 60 times the flow of the amazon river today – which is right now 20% of all the river flow on earth) – so about 12 times all the rivers on earth combined in one event.
As the water emerged from the Columbia River gorge, it backed up at the Wallula Gap and again at the 1 mile (1.6 km) wide narrows near Kalama, Washington. Some temporary lakes rose to an elevation of more than 400 ft (120 m), flooding the Willamette Valley to Eugene, Oregon and beyond. Iceberg rafted glacial erratics and erosion features are evidence of these events. Lake-bottom sediments deposited by the Missoula Floods are the primary reason for the agricultural richness of the Willamette Valley.