How many active volcanoes are located in the State of Alaska?
Alaska has more than 40 historically active volcanoes. 18. What is the most earthquake-prone State in the United States? Alaska is the most earthquake-prone State and one of the most seismically active regions in the world. Alaska experiences a magnitude 7 earthquake almost every year, and a magnitude 8 or greater earthquake on average every 14 years. 19. When was the last time that the volcanic mountain Mount Shasta, California, erupted? The last known eruption occurred approximately 200 years ago. Mount Shasta has erupted, on the average, at least once every 800 years during the last 10,000 years, and about once every 600 years during the last 4,500 years. 20. What is the origin of Crater Lake, Oregon? Crater Lake is of volcanic origin. It lies within the caldera of Mt. Mazama, a volcano of the Cascade Range that erupted 7,700 years ago. The mountain collapsed during its enormous eruption, forming a caldera. 21. What is the longest mountain chain on Earth? The Mid-Atlantic Ridge, whi
