Mauna Loa

Preparing for the next eruption of Earth's largest active volcano

U.S. Geological Survey Hawaiian Volcano Observatory

Mauna Loa, Earth’s largest active volcano, is located on the Island of Hawai‘i and is monitored by the U.S. Geological Survey’s (USGS) Hawaiian Volcano Observatory (HVO).

Mauna Loa erupted most recently in 1984 and will erupt again in the future, posing significant risk to people living on the flanks of the volcano. This geonarrative provides an overview of Mauna Loa’s eruptive history and hazards and includes interactive maps and datasets to help residents prepare for the next eruption ( Wright and others, 1992 ; Trusdell and others, 1996; Wolfe and Morris, 1996; Sherrod and others, 2007; Kauahikaua and others, 2017; Trusdell and Lockwood, 2017; Trusdell and Zoeller, 2017; Trusdell and Lockwood, 2019, 2020). 

This geonarrative text is adapted largely from the USGS Fact Sheet “ Mauna Loa—History, Hazards, and Risk of Living With the World’s Largest Volcano ” (Trusdell, 2012).

For up-to-date information on volcanic activity in Hawaii, please visit the  USGS HVO website .

To receive email notifications about volcanic activity at U.S. monitored volcanoes, subscribe to the  USGS Volcano Notification Service .

Mauna Loa Background

Mauna Loa Eruptive History

Photo: Mauna Loa looms above Kīlauea summit caldera (far left center) and nearly obscures Hualālai in the far distance (upper right).

Mauna Loa Eruption Hazards

Hazards associated with Mauna Loa eruptions include lava flows, volcanic gas emissions, and explosive events, as well as earthquakes, which can generate local tsunamis and landslides.

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Mauna Loa Interactive Maps

A series of maps are provided below. Use these maps to interactively explore Mauna Loa lava flows over the past 200 years, lava-flow hazard zones, steepest-descent lines, and lava-flow inundation zones. Suggestions for navigating the maps are listed below.

  • Move the map around by clicking and dragging. Zoom in and out using the “+” and “−” buttons on the bottom right-hand corner of the map. 
  • The legend is displayed in the left-hand corner of the map, or you can click on map features to learn more about them.
  • If you are an Island of Hawai‘i resident, locate points of interest and identify which lava-flow hazard zone and inundation zone they are in. Assess where you live and work and how a Mauna Loa eruption could potentially impact you and your family.

Mauna Loa will erupt again. The risks from a future eruption are increasing as the population on the Island of Hawaiʻi continues to grow and as development continues to expand on the flanks of the volcano.

Hazardous conditions associated with future eruptions of Mauna Loa can be anticipated based upon past behavior of the volcano. This provides an opportunity for island residents to plan ahead to minimize their risks from the next eruption.

What can you do? Learn about the hazards that could impact you and your community. Develop an emergency plan so that you are prepared in the event of a Mauna Loa eruption. Follow Hawaii County Civil Defense Agency guidance. Encourage and help others in your community to prepare. 

Photos: A network of monitoring instruments on Mauna Loa enables scientists at HVO to evaluate the potential for eruptive activity on Mauna Loa. HVO’s goal is to provide timely warnings of impending hazardous activity. 

References

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Haleakalā, Hualālai, Mauna Kea, Mauna Loa, and Kīlauea lava flow polygon data; select Kīlauea lava flow polygon data

Sherrod, D.R., Sinton, J.M., Watkins, S.E., and Brunt, K.M., 2007, Geologic map of the State of Hawaiʻi: U.S. Geological Survey Open-File Report 2007-1089. [Available at http://pubs.usgs.gov/of/2007/1089/.]

Hawaiʻi County Roads polyline data

Hawaii Statewide GIS Program, 2014, Roads - Hawaii County: State of Hawaii dataset. [Available at http://geoportal.hawaii.gov/datasets/636620e50cce4b44820c545eb3195a31_6.]

Mauna Loa lava inundation zones polygon data

Trusdell, F.A. and Zoeller, M.H., 2017,  Lava inundation zone maps for Mauna Loa, Island of Hawai‘i, Hawaii : U.S. Geological Survey Scientific Investigations Map 3387, 12 p., 10 sheets. doi:10.3133/sim3387.

Lava flow hazard zones

Wright, T. L., Chun, J.Y.F., Esposo, J., Heliker, C., Hodge, J., Lockwood, J.P., and Vogt, S.M., 1992, Map showing lava-flow hazard zones, Island of Hawaii: U.S. Geological Survey Miscellaneous Field Studies Map MF-2193, scale 1:250,000. [Available at http://pubs.usgs.gov/mf/1992/2193/ .]

Lava flow hazard zones polygon data

Hawaii Statewide GIS Program, 1991, Volcano Lava Flow Hazard Zones - Hawaii County: State of Hawaii dataset. [Available at https://geoportal.hawaii.gov/datasets/volcano-lava-flow-hazard-zones.]

Mauna Loa lava flow polygon data

Wolfe, E.W. (comp.), and Morris, J., 1996,  Geologic map of the Island of Hawaii : U.S. Geological Survey Miscellaneous Investigations Series Map I-2524-A, 18 p., 3 sheets. [Available at  https://pubs.er.usgs.gov/publication/i2524A .]

Digital Database of the Geologic Map of the Island of Hawaiʻi

Trusdell, F.A., Wolfe, E.W., and Morris, J., 1996,  Digital Database of the Geologic Map 

Mauna Loa Steepest-Descent Lines polyline data

Kauahikaua, Jim, Orr, Tim, Patrick, Matt, and Trusdell, Frank, 2017, Steepest-descent lines for Kīlauea, Mauna Loa, Hualālai, and Mauna Kea Volcanoes, Hawaiʻi: U.S. Geological Survey data release, https://doi.org/10.5066/F7FJ2DX0.

Geologic map of the central-southeast flank of Mauna Loa

Trusdell, F.A., and Lockwood, J.P., 2019,  Geologic map of the central-southeast flank of Mauna Loa Volcano, Island of Hawai‘i, Hawai i: U.S. Geological Survey Scientific Investigations Map 2932-B, scale 1:50,000, 2 sheets, pamphlet 23 p.,  https://doi.org/10.3133/sim2932B .

Geologic map of the northeast flank of Mauna Loa

Trusdell, F.A., and Lockwood, J.P., 2017,  Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai‘i, Hawaii : U.S. Geological Survey Scientific Investigations Map 2932-A, pamphlet 25 p., 2 sheets, scale 1:50,000,  https://doi.org/10.3133/sim2932A .

Geologic map of the Southern Flank of Mauna Loa

Trusdell, F.A., and Lockwood, J.P., 2020,  Geologic Map of the Southern Flank of Mauna Loa Volcano, Island of Hawai‘i, Hawaii : U.S. Geological Survey Scientific Investigations Map 2932-C, pamphlet 28 p., 2 sheets, scale 1:50,000,  https://doi.org/10.3133/sim2932C .

Holocene eruptive history of Mauna Loa

Lockwood, J.P., and Lipman, P.W., 1987, Holocene eruptive history of Mauna Loa Volcano, chap. 18 of Decker, R.W., Wright, T.L., and Stauffer, P.H., eds., Volcanism in Hawaii, v. 1.: U.S. Geological Survey Professional Paper 1350, p. 509–535. [Available at https://pubs.usgs.gov/pp/1987/1350/pdf/chapters/pp1350_ch18.pdf.]

Explosive history of Mauna Loa

Trusdell, F.A., Hungerford, J.D.G., Stone, J.O., Fifield, K., McCann, K., Wershow, H., Zaarur, S., and Boyd, M.D., 2019, Explosive eruptions at the summit of Mauna Loa: Lithology, modeling, and dating, in Poland, M.P., Garcia, M.O., Camp, V.E., and Grunder, A., eds., Field volcanology—A tribute to the distinguished career of Don Swanson: Geological Society of America Special Paper 538, p. 325–349, https://doi.org/10.1130/2018.2538(15).

National Park boundary polygon data

National Park Service - Park Unit Boundaries dataset. [Available at https://public-nps.opendata.arcgis.com/datasets/national-park-service-park-unit-boundaries/data.]

Images

Unless otherwise noted, all images and videos in this geonarrative are previously published through U.S. Geological Survey and available through the U.S. Geological Survey or at https://www.usgs.gov/observatories/hvo.

World Imagery basemap

Esri, DigitalGlobe, GeoEye, i-cubed, USDA FSA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community.

Mauna Loa basemap

U.S. Geological Survey, 2020, Mauna Loa: U.S. Geological Survey AGOL web map, accessed November, 2020.

Narrative content adapted from

Trusdell, F.A., 2012,  Mauna Loa—History, Hazards, and Risk of living With the World's Largest Volcano : U.S. Geological Survey Fact Sheet, 2012-3104, 4 p.

Geonarrative layout and content

Katherine M. Mulliken, Hawaiian Volcano Observatory, Research Corporation of the University of Hawaiʻi.

Geonarrative layout and content

Frank A. Trusdell, U.S. Geological Survey Hawaiian Volcano Observatory.

Photo: Mauna Loa looms above Kīlauea summit caldera (far left center) and nearly obscures Hualālai in the far distance (upper right).