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.
Pahoa, Hawaii
According to the United States Census Bureau, the CDP has a total area of , all of it land. Soils underlying the Pāhoa area are volcanic in origin, deriving from the currently active Kilauea Volcano. (Earth Metrics Inc., 1986) Kilauea is one of the Earth's most active volcanoes, with the January 2006 eruption being the longest rift zone eruption in Kilauea's 200-year recorded history. (Volcanology, 2007) The volcanic soils underlying Pāhoa are considered to have been generated by lava flows within the last 125 to 500 years. For example, the eruption of 1840 is known to have deposited a lava flow within of Pāhoa. Both Hawaii Route 130 and Hawaii Route 132 enter the town boundaries.