The U.S. government is closed. This site will not be updated; however, NOAA websites and social media channels necessary to protect lives and property will be maintained. To learn more, visit This is now the world's largest volcano, geologists say
In 2013, a team of scientists rocked geology fans when they reported that Mauna Loa, a 2,000-square-mile shield volcano in Hawaii, was probably not in fact the largest volcano in the world. That accolade, the team suggested, belonged to Tamu Massif, an extinct volcanic mountain on the seafloor east of Japan that appeared to be a single shield volcano covering a whopping 100,000 square miles, roughly the same size as the state of Arizona. Bill Chadwick is quoted.
