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.
Detroit Seamount
After its initial formation 81 million years ago, the volcano was active for 25 million years. Parts of the volcano appear to be older than the oldest volcano in the chain, Meiji Seamount. The 2005 analysis found that the volcano had been active throughout much of the Eocene (circa 52-34 million years ago), and that activity may have extended into the Oligocene (under 34 million years ago). The large difference between the youngest and oldest lavas provides evidence that the Hawaii hotspot migrated far more slowly than it does today; for example, Kohala volcano (the oldest volcano of Hawaii island) first emerged from the sea 500,000 years ago, and last erupted 120,000 years ago, a period of only 380,000 years in comparison to Detroit's 18 million or more years of volcanic activity. The large age difference (51 vs. 34 million years) between the submarine preshield stages and the post-shield rejuvenated stage seems to indicate that volcanoes in the chain can erupt again long after they are believed to be extinct. The volcano is known to have erupted intermediately in an underwater and shallow-water environment.