Volcano Watch: From Mauna Loa or Kilauea? A geologic whodunnit

  • J.M. Chang/ USGS photo A geologist examines a two-meter-thick (7 feet) tephra outcrop on the southeast flank of Mauna Loa.

Mauna Loa and Kilauea are the two most active volcanoes on the Island of Hawaii, and they have overlapping eruption histories. They are located in close proximity, with their summit craters only about 34 kilometers (21 miles) apart. In fact, part of Kilauea is built on the southeast flank of Mauna Loa, which is the older of the two volcanoes.