Hawaii hotspot
Hawaiian volcanoes are characterized by frequent rift eruptions, their large size (thousands of cubic kilometers in volume), and their rough, decentralized shape. Rift zones are a prominent feature on these volcanoes, and account for their seemingly random volcanic structure. The tallest mountain in the Hawaii chain, Mauna Kea, rises above mean sea level. Measured from its base on the seafloor, it is the world's tallest mountain, at ; Mount Everest rises above sea level. Hawaii is surrounded by a myriad of seamounts; however, they were found to be unconnected to the hotspot and its volcanism. Kīlauea has erupted continuously since 1983 through Puʻu ʻŌʻō, a minor volcanic cone, which has become an attraction for volcanologists and tourists alike.
Kaena Ridge
Kaena Ridge, also referred to as the Kaena Volcano, is a submerged remnant of an ancient shield volcano that is to the north of and once comprised the northern section of the Hawaiian Island of Oahu. Ka'ena Ridge was the oldest of the three volcanoes to form Oahu and it was also the shortest when it grew out of sea level. It was about 3,000 ft.