4.) When ice covered almost all of North America, known as the ice age, water began to build up against a 2,500ft ice dam. Soon, when the water presure was at it’s highest, at 2,000ft in dept, the ice broke. This resulted in a catastrphic flood he size of Lake Erie and Onterio combined! The water swept over Eastern Washington moving from 30 to 50 mph.
Dates- In 1923 the theory ws discovered. The ice dam formed more than 15,000 years ago.
Course- The courses path was almost 2,000 miles in deph in some places. About 50 cubic miles of Western Montanah was full of water.
Evidence- Some of the land forms that were left behind from the Missoula Floods were; empty canyons, random bolders in plataue, rip marks in mountians, dry water falls, large amounts of dry land, verticle colums of basalt, deep colonies where water flooded, dry steam beds, sad bars, torn sediments of mountians creating clifs with water falls, wiper out canyons, carver ripple marks.
Cause of Plate Techtonics
6.) Most of earths movement is caused by the thermal convection currents in the mantle. This causes hot lava to rise and cool lava to sink. The flooding magma causes the plates to move along with them. The convection currents are caused by the intence heat of the core and the cool air in the lithosphere. During this change in temperature, …show more content…
East of the cascades, lava flowed from large cracks in the earth, far from any volcano. Where the earth’s crust is weak, lava may spill out and spread hundereds of squar miles. This prosses is called fissure eruption, or lava flood. Flat platforms called plateaus, are left from the lava cooling. Streams of water carve channels into the surface. Fissure eruption began 20 to 25 million years ago in the Picific Northwest from plateaus East of the cascades almost 10,000 squar miles were covered as deep as