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What Are the Two Towering Volcanic Giants in the U.S.?

Identifying the most towering volcanoes in the U.S. depends upon how you measure their height. The first option would be based on a volcano's height above sea level. However, there are many volcanoes on oceanic plates that must be considered in terms of their absolute height from the sea floor. Accordingly, the two tallest volcanoes in the U.S., in terms of elevation above sea level, are Mount Bona and Mount Blackburn, while the two tallest volcanoes in the U.S., in terms of absolute height, are Mauna Loa and Mauna Kea.

Mount Bona
- Mount Bona, located in the St. Elias Mountains of eastern Alaska, is the highest volcano in the U.S. in terms of height above sea level. The composite, or strato, volcano rises 16,420 feet. Mount Bona's last eruption, around A.D. 800, was one of the largest explosive eruptions in North America during the last 2,000 years. This volcano lies in a subduction zone where the Pacific plate is being forced under the North American plate.
Mount Blackburn
- Mount Blackburn, located to the northwest of Mount Bona in the Wrangell Mountains of eastern Alaska, is the second highest volcano in the U.S. in terms of height above sea level. Mount Blackburn rises 16,390 feet, with a volume of 250 cubic miles. This volcano is estimated to be five million years old, with no activity during the last 3.4 to 4.2 million years. This volcano lies in the Wrangell volcanic field, a 4,000 square mile basaltic lava field. While located in a subduction zone, Mount Blackburn and the other Wrangell volcanoes are shield volcanoes. This may be the result of a hotspot that would account for the area's fluid lava flows over the past 26 million years, as opposed to the thicker, more explosive lava of the nearby St. Elias volcanoes.
Mauna Loa
- Hawaii's Mauna Loa, Hawaiian for "Long Mountain," is the largest volcano in the world and second tallest. While only 13,677 feet above sea level, the massive shield volcano rises 31,677 in total height from the sea floor. Mauna Loa covers an area of 2,035 square miles, more than half of the island of Hawaii, and has a total volume of 19,000 cubic miles. The volcano is believed to be 700,000 to a million years old and has, at the time of publication, erupted with basaltic lava flows on 33 occasions since 1843.
Mauna Kea
- Hawaii's Mauna Kea volcano, Hawaiian for "White Mountain," is the tallest volcano in the world. Thanks to its cinder cones on the summit, this shield volcano is 119 feet taller than Mauna Loa. This volcano rises 13,796 feet above sea level, with an absolute height of 31,796 feet above the sea floor. Mauna Kea covers an area of 920 square miles, with a total volume of 7,200 cubic miles. The volcano is approximately one million years old. Mauna Kea is currently dormant, with its last eruption occurring around 4,500 years ago.

Nature