ods of lava have built large area of continents like the Columbia Plateau in the Pacific Northwest. Volcanoes also make soil as the ash, pumice and lava break down. This mixed with plant and animal remains makes very rich soil. In 1980, MSH erupted six more time, usually blowing ash into the air and causing pumice to slide down the side of the mountain. In June and August, the lava that came out from the top was thick enough to finally form a new dome. This dome was destroyed only to be formed again in October. After this, the eruptions only added to the size of the dome making it larger. What came out of MSH The erupting volcano sent out material and debris of all sizes. The term of all of this is tephra. the material that was blown out of the volcano was classified by its size. 0.1 inches or less =Ash 0.1-2.5 inches = Lapillo or little stones 2.5 inches and larger = Bombs and blocks Bombs are rocks that are soft when they are ejected while blocks are solid. Both bombs and blocks can land miles away and fly at speeds of 1250 miles per hour. The blocks destroy whatever they land on while the bombs explode and burst into red hot liquid when they land. The earth has many volcanoes, the majority of them circling the Pacific Ocean. These volcanoes are known as the Ring of Fire. Scientists know that he volcanoes are in this formation because of the movement of the earth's crust. There are over 400 active volcanoes in the world. They are found in weak places, or faults, in the Earth's crust, where two of the Earth's plates meet. Volcanoes and earthquakes occur in the same general area. Volcanoes seem to relieve some of the pressure of the Earth's mantle, so the earthquakes near them are milder. The band of faults around the edge of the Pacific Ocean has most of the worlds active volcanoes. In the Ring of Fire, many of the volcanoes are underwater and as they grow they become islands. The Cascade Range that MSH is a part of was formed by the s...
