Composite volcanoes are also known as strato volcanoes. Their formation consists of alternating layers of lava and rock. They occur along subduction zones and have many different forms. One of those forms is multi-summit, like Mount Shasta.

Mount Shasta is found in the United States. It is currently dormant with its last eruption being in 1786. In the last 4,500 years, Shasta has erupted about once every 600 years. This majestic beauty is 4,317 meters high and the second largest mountain in the Cascade Range. The lower slopes of Shasta are strongly eroded. The Shastina cone funneled a large pyroclastic flow around 9,230 years ago. It releases blocky basaltic andesite lava.

While Mount Shasta is the second largest in the Cascade Range, Mount Ranier is the largest, at 4,392 meters high. There are many steam vents and hot rocks near the summit, and the volcano is always emitting steam. It's last eruption...