Mauna Loa Volcano


About Mauna Loa Volcano


Meaning “Long Mountain” in Hawaiian, Mauna Loa is the second tallest of the five volcanoes found on Hawaii’s Big Island.It is an active shield volcano, and the summit lies within Hawaii Volcanoes National Park.

Mauna Loa is not steep. With an incline no greater than 12 degrees and makes judging distance against elevation rather hard. It would take early Hawaiian explorers weeks and many stops to make it to the summit.

The active volcano Mount Kilauea actually sits on the slopes of Mauna Loa, but due to differences in lava composition and magma chambers they are considered to be different volcanoes.

The Mauna Loa Observatory near the summit plays a key role in measuring atmospheric changes, and has been measuring changes in carbon dioxide levels since 1956. The Mauna Loa Solar Observatory is dedicated to measuring changes in solar emissions and radiation since 1965.


Mauna Loa was most recently active in 1984 with an eruption lasting about 3 weeks. Eruptions in 1926 and 1950 destroyed villages on the slopes, and part of Hilo Town is built on flows from eruptions in the 1800′s. Flows from the 1984 eruption stopped about 2.5 miles outside of Hilo’s rural residences.

In 2009, a series of earthquakes raised concerns of another possible eruption, which never occurred. A large earthquake in 2006 caused minor damage to many observatories on the Big Island, and some were temporarily out of service while receiving repairs.

Ancient Hawaiians made the grueling trek to the summit of Mauna Loa on what is known today as the Ainapo Trail. In 1794 Archibald Menzies became the first outsider of Hawaii to trek the summit.

Facts & Trivia

  • Island: Big Island
  • Insider Tip: Be sure to stop and take rest breaks while your body acclimates to the atmosphere and lack of oxygen.
  • Fun Fact: Mauna Loa is estimated at being active for the last 700,000 years!
  • What to Expect: Snow in the winter, lack of oxygen due to elevation, volcanic fog or "vog" and a lack of amenities.
  • Pop Culture: The popular Mauna Loa Macadamia Nut Company takes it's name from this mighty peak and has a factory in Hilo Town.