Mount Bona is the tallest volcano in Alaska and the United States. Located in the Saint Elias Mountains, it reaches 16,358 feet. Mount Bona is also the fifth-highest mountain in the United States and the fourth-highest in North America. Prince Luigi Amedeo, a member of the Italian royalty, named the mountain in 1897 after his racing yacht, the Bona. The first recorded ascension of the mountain was in 1930. Mount Bona is classified as a stratovolcano. Glaciers and ice cover the majority of the mountain.
One of the most explosive volcanoes in Alaska is Mount Pavlof. This volcanic peak is in the Aleutian Range of the Alaskan Peninsula. Since 1762, Mount Pavlof has experienced approximately 40 volcanic eruptions, the most recent of which occurred in the summer of 2007. Pavlof is a stratovolcano and is about 8,200 feet high. The first ascent of Mount Pavlof in recorded history happened in 1924. Mount Pavlof has a twin peak, Pavlof Sister, which is also volcanic; however, Mount Pavlof is much more active than Pavlof Sister.
The Novarupta volcano is in Katmai National Park on the Alaska Peninsula. In 1912, Novarupta experienced the most cataclysmic eruption in the 20th century. The United States Geological Survey says the Novarupta eruption was 10 times more explosive than the 1980 Mount St. Helens eruption in Washington State. The aftermath of the Novarupta explosion caused complete darkness in Alaska for nearly a week. The eruption also created acid rain that reached as far south as Vancouver, British Columbia, Canada.
Many of Alaska's active volcanoes are stratovolcanoes. These volcanoes have conical shapes at their peaks and are steeper than shield volcanoes which resemble domes. Stratovolcanoes have more eruptive explosions than shield volcanoes, which create fluid lava flows rather than eruptions. However, the fluid lava flows from shield volcanoes travel greater distances than the lava from stratovolcano eruptions. Stratovolcanoes are also called "composite cones," due to their shape and the multiple layers of rocks that form the mountain.