Seismic event devastated Ka'ū 150 years ago
[Left] This cross-section through the south part of the Island of Hawai'i illustrates the hypocenter of the 1868 great Kaʻū earthquake (red star), located on the décollement (bold black line) between Mauna Loa (brown) and the ancient ocean floor (tan). Earth's lithospheric mantle and the ocean are represented in green and blue, respectively. [Right] The striped pattern on this map of Hawaiʻi Island indicates the areas of Mauna Loa and Kīlauea that must have moved along the décollement to produce the magnitude-7.9 Kaʻū earthquake in 1868. Red lines depict the rift zones on Mauna Loa (left) and Kīlauea (right). The approximate epicenter of the earthquake is shown as a yellow dot, and the direction of slip along the décollement is shown with black arrows. Graphics are modified from Max Wyss, Bulletin of the Seismological Society of America, 1988.