Mayor Island/Tuhua

Mayor Island (or Tuhua) is a dormant shield volcano located off the Bay of Plenty coast of New Zealand's North Island. It lies 35 kilometres (22 mi) north of Tauranga and covers 13 km (5 sq mi). The island is quite steep along its coast and rises to 355 metres (1,165 ft) above sea level. A saddle about 75 metres (246 ft) deep separates it from the North Island, while the other side of the volcano rises from the seafloor some 400–500 metres (1,312–1,640 ft) beneath the waves.^[1] The island is believed to have risen from the sea about 7000 years ago. Hot springs abound, and there are two small crater lakes, Green Lake and Black Lake. These lie within two overlapping calderas formed in explosive eruptions 36,000 and 6,340 years ago. Mayor Island has exhibited a wide range of eruptive styles, including fire fountains, Strombolian explosions, extrusion of lava domes, phreatomagmatic explosions, Plinian falls and ignimbrite. The most recent lava flows have been dated at between 500 and 1,000 years old.

• http://en.wikipedia.org/wiki/Mayor Island/Tuhua