Learn about the largest active volcano on Earth Mauna Loa in Hawaii. Discover its massive size, eruption history, and fascinating facts about its role in shaping the Hawaiian Islands.

The Office of Hawaiian Affairs (OHA) Board of Trustees today approved the immediate withdrawal of its two longstanding lawsuits concerning Maunakea, marking a pivotal shift towards collaborative ...

A spacecraft's-eye view over the landscapes of Mars has just given us a first-of-its-kind glimpse of the giant, ancient edifice known as Arsia Mons.

An observatory high on Hawaii's Mauna Loa volcano that measures carbon dioxide in the atmosphere has reported its highest ever seasonal peak concentration of the greenhouse gas. For the first time ...

Mauna Loa, situated in Hawaii, is the Earth's largest volcano by both volume and area. This massive shield volcano stands 4,169 meters above sea level and stretches another 5 kilometers beneath ...

The United States leads the world with 165 Holocene volcanoes, mostly in Alaska, Hawaii, and the Pacific Northwest. Active ...

For the first time, the seasonal peak of carbon dioxide concentrations in the atmosphere exceeded 430 parts per million (ppm) at NOAA’s Mauna Loa Observatory on Hawaii, scientists from NOAA and ...

"For comparison, the largest volcano on Earth is Mauna Loa. From its base on the sea floor, Mauna Loa measures only 6.3 miles [10 kilometers] high and 75 miles [121 kilometers] in diameter." ...

What Is the Largest Active Volcano in the World? Hawaii's Mauna Loa—capping off at 4 kilometers (2.5 miles) above sea level—is the world's largest active volcano.

Please visit HVO’s website for past Volcano Watch articles, Kilauea and Mauna Loa updates, volcano photos, maps, recent earthquake information, and more. Email questions to askHVO@usgs.gov.