The Brothers volcano is a Pacific Ocean submarine volcano

Submarine volcano

Submarine volcanoes are underwater fissures in the Earth's surface from which magma can erupt. They are estimated to account for 75% of annual magma output. The vast majority are located near areas of tectonic plate movement, known as ocean ridges...

 in the Kermadec Arc

Kermadec Islands

The Kermadec Islands are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga...

, 340 kilometres north east of New Zealand's Whakaari/White Island

Whakaari/White Island

Whakaari/White Island is an active andesite stratovolcano, situated from the east coast of the North Island of New Zealand, in the Bay of Plenty. The nearest mainland towns are Whakatane and Tauranga....

. Within its oval outline, which measures 13 km by 8 km, it contains a 3 km wide caldera with walls 300-500 m high. A dacite dome rises 350 m from the caldera floor (which lies 1850 m below sea level), with a smaller dome just to its northeast. The caldera walls and the larger dome host numerous hydrothermal vents, which send plumes of hot water 750 m up through the water column. It is the most hydrothermally active volcano known in the Kermadec Arc.

A joint expedition by the United States, New Zealand and Germany mapped the volcano in detail in 2007.

External links

• Topographic map of the Brothers volcano