We are a class of fifth graders in Moscow, Idaho (downwind of Mt. St. Helens.) We are learning about the volcanic activity on the big island of Hawaii. When we look at the map and read updates about the eruptions, we are confused about the place names: Mauna Kea, Mauna Loa, Kilauea, Pu'u O'o. Are these all part of the same volcano, or are there several volcanoes on the island?
There are many volcanoes listed together
on maps of the ("big") island of Hawaii and all of them are
related to the Hawaiian hotspot, so it is easy to be confused.
The basic structure of the island is giant shield volcanoes with many satellite vents commonly aligned along rift zones of each major volcano. Magma rises from the Earth's mantle under the summit of the shield volcanoes and some of it is erupted on the flanks of these shields along rift zones. Kilauea and Puu Oo area a good example of this relationship: Puu Oo is a satellite vent for the shield volcano Kilauea. To learn more about this eruption, visit our web site: www.soest.hawaii.edu/GG/HCV/kilauea.html
There are five shield volcanoes on the island and one to the south off shore, Loihi. Two of the five shields are probably extinct: Kohala (on the north, which last erupted 100,000 years ago) and Mauna Kea (northeast side which last erupted ~4000 years ago). Hualalai on the west side of the Big Island last erupted in 1801. The final Big Island volcano is Mauna Loa which last erupted in 1984. Loihi, the submarine volcano erupted last summer. To learn more about Loihi and its recent eruption, visit our web site: www.soest.hawaii.edu/GG/HCV/loihi.html
Dr. Mike Garcia, Professor of Geology
Department of Geology and Geophysics
University of Hawaii, Honolulu, HI 96822