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That Hawaii’s Mauna Kea or White Mountain is the world’s tallest peak, measuring 16,400 m (47,000 feet) from base to summit? And that underwater volcanoes account for 75% of annual magma output? Just like Mauna Kea’s height, with 10,000 m (33,500 feet) under sea level, underwater volcanoes and their eruptions often go unnoticed. And because the usual signs like rumbling and smoke are harder to detect, it is all the more spectacular when an underwater volcano visibly erupts. Follow us around the globe for some of the most stunning sights.
It is estimated that there are currently 5,000 active underwater volcanoes worldwide; of various sizes, standing alone or forming ridges with other volcanoes, of which the highest ones will rise above the surface as islands. The submerged part of the Hawaiian Islands, for example, is one of the largest and longest volcanic ridges – more than 2,400 km (1,500 miles) long.As underwater fissures in the earth’s surface, most submarine volcanoes are located near areas of tectonic plate movement. Clusters of terrestrial volcanoes therefore point to hotbeds of underwater volcanic activity as well, like the places portrayed here around Hawaii, California, Iceland, Japan, New Zealand, the Caribbean and Antarctica.
Molokini Crater (above) in Maui County, Hawaii is a crescent shaped “island” popular with scuba divers, snorkelers and seabirds alike, but it used to be a fully round, volcanic crater. One can just imagine the underwater volcano in its heyday, forming a few new islands through eruption.Morro Rock in California is part of a series of volcanic plugs known as the “Nine Sisters,” created over 20 million years ago. The explosion of a submarine volcano created Morro Rock, a giant piece of lava that, once in contact with the sea water, formed a solid crust and settled in the neck of the volcano, similar to a cork resting in the neck of a bottle. Champagne-like explosions are not to be expected as the volcano is not active any more. The rock was named “El Morro” (pebble) by Portuguese explorers in the 16th century when the volcano’s crater was still visible. Today, erosion is constantly shaping Morro Rock.
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