Mauna Kea
Mauna Kea ( or , ) is a dormant volcano on the island of Hawaii. Its peak is above sea level, making it the highest point in the state of Hawaii. Most of the mountain is under water, and when measured from its oceanic base, Mauna Kea is the tallest mountain in the world measuring over . Mauna Kea is about a million years old, and has thus passed the most active shield stage of life hundreds of thousands of years ago. In its current post-shield state, its lava is more viscous, resulting in a steeper profile. Late volcanism has also given it a much rougher appearance than its neighboring volcanoes due to construction of cinder cones, decentralization of its rift zones, glaciation on its peak, and weathering by the prevailing trade winds. Mauna Kea last erupted 6,000 to 4,000 years ago and is now considered dormant. The peak is only about higher than its more massive neighbor, Mauna Loa.
Detroit Seamount
Detroit Seamount has a wide (100,000 square kilometers) base and rises from the bottom of the abyssal plain to a depth of approximately ; in fact, it is as wide as Hawaii island at the head of the chain. The width of the seamount, as well as the extremely gentle slope, which is very shallow even for a Hawaiian shield volcano, seem to show that the seamount suffered a catastrophic collapse sometime in its history; such a collapse is a relatively common event in the growth of Hawaiian volcanoes, caused when the volcanoes grow so fast that they destabilize. A sequence of sediments to thick compose the volcano, in several layers. Some papers refer to only the shallowest part of the volcano as Detroit Seamount, and the rest of the seamount as the "Detroit Rise." The tallest volcanic cones of the seamount peak to above the rest of the seamount.