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Prepare: Mauna Loa Resources

By Mauna Loa

Volcano Notification Service

Stay up to date on volcanic activity in Hawaii

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Volcanic Hazards in Hawaii

Eruptions and earthquakes contribute to numerous hazards

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Mauna Loa Multimedia

Photos, videos, maps, and other Mauna Loa multimedia

Multimedia

Mauna Loa Geology & History

Mauna Loa has erupted 33 times since the year 1843

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Frequently Asked Questions about Mauna Loa

What is happening and how do I stay informed?

FAQ

Mauna Loa is Earth's largest active volcano and covers just over half of the Island of Hawaiʻi. It erupted most recently in 2022 and it will erupt again. This page provides resources to help you understand Mauna Loa eruption hazards and develop an emergency plan. 

Latest Mauna Loa Update

Mauna Loa Lava Inundation Zones

USGS maps identify lava inundation zones for Mauna Loa...
View Here

Lava Flow Hazard Zones

Color graphic showing lava flow hazard zones
View Here

Frequently-Asked-Questions

image related to volcanoes. See description
Read Here
Hawaiʻi Volcanoes National Park Information:

https://www.nps.gov/havo/index.htm

 
County of Hawaiʻi Civil Defense Agency:

https://hawaii-county-volcano-hazards-hawaiicountygis.hub.arcgis.com/

 

What can you do before a future Mauna Loa eruption? 

Learn the Hazards

eruptive fissures along the Northeast Rift Zone of Mauna Loa
Sources/Usage: Public Domain. View Media Details
As the sun rose above Mauna Kea (background) on July 6, 1975, eruptive fissures along the Northeast Rift Zone of Mauna Loa fed voluminous ‘a‘ā lava flows that quickly moved down the north flank of the volcano.

Hazards associated with Mauna Loa eruptions include: 

  • Large and fast-moving lava flows
  • Volcanic air pollution (VOG)
  • Fine rock particles downwind
  • Damaging earthquakes
  • Ground cracks and fissures
  • Local tsunami in coastal areas

Learn more on the HVO volcanic hazards webpage: https://www.usgs.gov/observatories/hvo/hazards

See the geonarrative: Mauna Loa: Preparing for the next eruption of Earth's largest active volcano.

Prepare

Stay Informed

Official sources of information:

What can you do during a future Mauna Loa eruption? 

  • Get information from official sources
  • Implement the emergency plan that you and your family have developed
  • Heed County of Hawaiʻi guidance and evacuate if necessary

 

 

Mauna Loa reference maps

Color map of lava flow response times
Sources/Usage: Public Domain. View Media Details
This map shows the response time people can expect based on Mauna Loa eruptions over the past 200 years.  Different sectors around Mauna Loa are colored according to how quickly lava flows can reach populated areas.  The warmer the color, the more quickly the flows travel.  Mauna Loa lava flows over the past 200 years are shown in gray, and the numbers along the coastline indicate lava travel times to the ocean after the vent(s) opened.  Large, bold numbers record the average effusion rates for the different parts of the volcano in millions of cubic meters per day (Mm3/d).
image related to volcanoes. See description
Sources/Usage: Public Domain. View Media Details
Map showing the subaerial extents of historical lava flows from Mauna Loa. Lava flow hazard zones and districts of the County of Hawai‘i are also depicted.
Map of post-1823 lava flows erupted from Mauna Loa (gray) and numbe...
Sources/Usage: Public Domain. View Media Details
Slope map of Mauna Loa, including lava flows erupted since 1823 (gray), showing the approximate number of hours or days it took for a flow to advance from the vent location to the ocean or maximum reach of a flow. One flow that moved down the steep slopes on west flank of Mauna Loa reached the ocean in as little as 3 hours after the vent started erupting in 1950. The bold numbers (for example, 12Mm3/d) are the average rates of lava effusion (outpouring of lava) in millions of cubic meters per day. Note the west flank has the steepest slopes (red-orange areas), shortest distance from vent to the ocean, and the highest average rate of effusion during eruptions, resulting in precious little time for warning residents during an eruption from the Southwest Rift Zone of Mauna Loa.

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March 10, 2021—Mauna Loa eruption response times

March 10, 2021—Mauna Loa eruption response times over the past 200 years

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

June 5, 2020—Subaerial extents of Mauna Loa lava flows from the past 200 years

Map showing the subaerial extents of historical lava flows from Mauna Loa. Lava flow hazard zones and districts of the County of Hawai‘i are also depicted.

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Geologic map of the southern flank of Mauna Loa Volcano, Island of Hawai‘i, Hawaii

On the Island of Hawaiʻi, Mauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions began with only brief seismic unrest, whereas others followed several months to a year of increased seismicity. Once underway, its eruptions can produce lava flows that may reach the sea in less than 24 hours, severing roads and utilities. In t
By
Volcano Hazards Program, Volcano Science Center

Geologic map of the central-southeast flank of Mauna Loa Volcano, Island of Hawaii, Hawaii

Mauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions began with only brief seismic unrest, while others followed several months to a year of increased seismicity. Once underway, its eruptions can produce lava flows that may reach the sea in less than 24 hours, severing roads and utilities. For example, lava flows erupted
By
Volcano Hazards Program, Volcano Science Center

Map of post-1823 lava flows erupted from Mauna Loa

Slope map of Mauna Loa, including lava flows erupted since 1823 (gray), showing the approximate number of hours or days it took for a flow to advance from the vent location to the ocean or maximum reach of a flow. 

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Map of lava flows that have erupted on Mauna Loa Volcano — 1843-1985

Map of lava flows that have erupted on Mauna Loa Volcano from 1843-1984.
By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Lava inundation zone maps for Mauna Loa, Island of Hawaiʻi, Hawaii

Lava flows from Mauna Loa volcano, on the Island of Hawaiʻi, constitute a significant hazard to people and property. This report addresses those lava flow hazards, mapping 18 potential lava inundation zones on the island.
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Volcano Hazards Program, Volcano Science Center

Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai'i, Hawaii

SummaryMauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions were preceded by only brief seismic unrest, while others followed several months to a year of increased seismicity.The majority of the eruptions of Mauna Loa began in the summit area (>12,000-ft elevation; Lockwood and Lipman, 1987); yet the Northeast Rift Zone (
By
Volcano Hazards Program, Volcano Science Center

Map showing lava inundation zones for Mauna Loa, Hawai'i

The Island of Hawai‘i is composed of five coalesced basaltic volcanoes. Lava flows constitute the greatest volcanic hazard from these volcanoes. This report is concerned with lava flow hazards on Mauna Loa, the largest of the island shield volcanoes. Hilo lies 58 km from the summit of Mauna Loa, the Kona coast 33 km, and the southernmost point of the island 61 km.Hawaiian volcanoes erupt two morph
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Volcano Hazards Program, Volcano Science Center, Hawaiian Volcano Observatory

The lava flow that came to Hilo—The 1880–81 eruption of Mauna Loa volcano, Island of Hawai‘i

The Mauna Loa eruption sequence of 1880–81 consists of two eruptions. The May 1880 eruption in Mokuʻāweoweo at the summit of Mauna Loa lasted just a few days and was followed 6 months later by three lava flows that issued from vents along the Northeast Rift Zone. The November 1880 eruption lasted almost a year and one of its flows nearly reached Hilo Bay.Public reaction in Hilo to the advancing la
Authors
James P. Kauahikaua, Ben Gaddis, Ku`ulei Kanahele, Ken Hon, Valerie Wasser
By
Volcano Hazards Program, Volcano Science Center, Office of Tribal Relations

Mauna Loa--history, hazards and risk of living with the world's largest volcano

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Community preparedness for lava flows from Mauna Loa and Hualālai volcanoes, Kona, Hawai'i

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Chris E. Gregg, Bruce F. Houghton, Douglas Paton, Donald A. Swanson, David M. Johnston
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Volcano Watch — Recent events at Mauna Loa remind us to be prepared for quick changes

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Read Article
Volcano Watch — Mauna Loa: The sleeping giant

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Read Article
Volcano Watch — Lessons for the future from Mauna Loa’s 1916 eruption

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The year 1916 not only marked the birth of Hawaiʻi Volcanoes National Park, but also is remembered for the eruption of the Honomalino flow from the...

Read Article
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Volcano Watch — Remembering Mauna Loa’s eruption on July 5–6, 1975

Volcano Watch — Remembering Mauna Loa’s eruption on July 5–6, 1975

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Volcano Watch — Tiny changes at Mauna Loa’s summit hold big clues

Volcano Watch — Tiny changes at Mauna Loa’s summit hold big clues

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Volcano Watch — “By failing to prepare, you are preparing to fail.” – Benjamin Franklin

Volcano Watch — “By failing to prepare, you are preparing to fail.” – Benjamin Franklin

Mauna Loa has been in the news lately, as the volcano continues to awaken from its slumber. While an eruption of Mauna Loa is not imminent, now is the...

Read Article
Volcano Watch — When will Mauna Loa erupt next?

Volcano Watch — When will Mauna Loa erupt next?

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Volcano Awareness Month 2021 Program – When will Mauna Loa erupt next?

Volcano Awareness Month 2021 Program – When will Mauna Loa erupt next?

In this talk, USGS Hawaiian Volcano Observatory geologist Frank Trusdell, who has studied Mauna Loa for two decades, presents a roughly 40-minute talk...

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Volcano Watch — HVO looks to the past to better understand future Mauna Loa eruptions

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Mauna Loa, the largest active volcano on Earth, has erupted, on average, every 5–6 years during the past 3,000 years.

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Related Content

March 10, 2021—Mauna Loa eruption response times

March 10, 2021—Mauna Loa eruption response times over the past 200 years

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

June 5, 2020—Subaerial extents of Mauna Loa lava flows from the past 200 years

Map showing the subaerial extents of historical lava flows from Mauna Loa. Lava flow hazard zones and districts of the County of Hawai‘i are also depicted.

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Geologic map of the southern flank of Mauna Loa Volcano, Island of Hawai‘i, Hawaii

On the Island of Hawaiʻi, Mauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions began with only brief seismic unrest, whereas others followed several months to a year of increased seismicity. Once underway, its eruptions can produce lava flows that may reach the sea in less than 24 hours, severing roads and utilities. In t
By
Volcano Hazards Program, Volcano Science Center

Geologic map of the central-southeast flank of Mauna Loa Volcano, Island of Hawaii, Hawaii

Mauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions began with only brief seismic unrest, while others followed several months to a year of increased seismicity. Once underway, its eruptions can produce lava flows that may reach the sea in less than 24 hours, severing roads and utilities. For example, lava flows erupted
By
Volcano Hazards Program, Volcano Science Center

Map of post-1823 lava flows erupted from Mauna Loa

Slope map of Mauna Loa, including lava flows erupted since 1823 (gray), showing the approximate number of hours or days it took for a flow to advance from the vent location to the ocean or maximum reach of a flow. 

By
Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Map of lava flows that have erupted on Mauna Loa Volcano — 1843-1985

Map of lava flows that have erupted on Mauna Loa Volcano from 1843-1984.
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Volcano Hazards Program, Hawaiian Volcano Observatory, Mauna Loa

Lava inundation zone maps for Mauna Loa, Island of Hawaiʻi, Hawaii

Lava flows from Mauna Loa volcano, on the Island of Hawaiʻi, constitute a significant hazard to people and property. This report addresses those lava flow hazards, mapping 18 potential lava inundation zones on the island.
By
Volcano Hazards Program, Volcano Science Center

Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai'i, Hawaii

SummaryMauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions were preceded by only brief seismic unrest, while others followed several months to a year of increased seismicity.The majority of the eruptions of Mauna Loa began in the summit area (>12,000-ft elevation; Lockwood and Lipman, 1987); yet the Northeast Rift Zone (
By
Volcano Hazards Program, Volcano Science Center

Map showing lava inundation zones for Mauna Loa, Hawai'i

The Island of Hawai‘i is composed of five coalesced basaltic volcanoes. Lava flows constitute the greatest volcanic hazard from these volcanoes. This report is concerned with lava flow hazards on Mauna Loa, the largest of the island shield volcanoes. Hilo lies 58 km from the summit of Mauna Loa, the Kona coast 33 km, and the southernmost point of the island 61 km.Hawaiian volcanoes erupt two morph
By
Volcano Hazards Program, Volcano Science Center, Hawaiian Volcano Observatory

The lava flow that came to Hilo—The 1880–81 eruption of Mauna Loa volcano, Island of Hawai‘i

The Mauna Loa eruption sequence of 1880–81 consists of two eruptions. The May 1880 eruption in Mokuʻāweoweo at the summit of Mauna Loa lasted just a few days and was followed 6 months later by three lava flows that issued from vents along the Northeast Rift Zone. The November 1880 eruption lasted almost a year and one of its flows nearly reached Hilo Bay.Public reaction in Hilo to the advancing la
Authors
James P. Kauahikaua, Ben Gaddis, Ku`ulei Kanahele, Ken Hon, Valerie Wasser
By
Volcano Hazards Program, Volcano Science Center, Office of Tribal Relations

Mauna Loa--history, hazards and risk of living with the world's largest volcano

Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves). The County of Hawaiʻi (Island of Hawaiʻi) is the fastest growing County in the State of Hawaii. Its expanding population
Authors
Frank A. Trusdell
By
Natural Hazards Mission Area, Volcano Hazards Program, Volcano Science Center

Community preparedness for lava flows from Mauna Loa and Hualālai volcanoes, Kona, Hawai'i

Lava flows from Mauna Loa and Hualālai volcanoes are a major volcanic hazard that could impact the western portion of the island of Hawai'i (e.g., Kona). The most recent eruptions of these two volcanoes to affect Kona occurred in A.D. 1950 and ca. 1800, respectively. In contrast, in eastern Hawai'i, eruptions of neighboring Kilauea volcano have occurred frequently since 1955, and therefore have be
Authors
Chris E. Gregg, Bruce F. Houghton, Douglas Paton, Donald A. Swanson, David M. Johnston
By
Natural Hazards Mission Area, Volcano Hazards Program, Volcano Science Center
Volcano Watch — Recent events at Mauna Loa remind us to be prepared for quick changes

Volcano Watch — Recent events at Mauna Loa remind us to be prepared for quick changes

The last eruption of Mauna Loa occurred in 1984 and began in a style typical of the volcano. At 10:55 p.m. on March 24, 1984, the rate of earthquakes...

Read Article
Volcano Watch — Mauna Loa: The sleeping giant

Volcano Watch — Mauna Loa: The sleeping giant

Covering over half of the Island of Hawai‘i, Mauna Loa is sometimes referred to as a “sleeping giant” because it hasn’t erupted in 38 years after...

Read Article
Volcano Watch — Lessons for the future from Mauna Loa’s 1916 eruption

Volcano Watch — Lessons for the future from Mauna Loa’s 1916 eruption

The year 1916 not only marked the birth of Hawaiʻi Volcanoes National Park, but also is remembered for the eruption of the Honomalino flow from the...

Read Article
Mauna Loa: are you ready for the next eruption? — Volcano Awareness Month 2022 Short Feature

Mauna Loa: are you ready for the next eruption? — Volcano Awareness Month 2022 Short Feature

The tenth in a series of recorded talks by HVO staff that will be posted on our website throughout the month of January. These talks are presented as...

Read Article
Mauna Loa: Preparing for the next eruption of Earth’s largest active volcano — Volcano Awareness Month 2022 Geonarrative

Mauna Loa: Preparing for the next eruption of Earth’s largest active volcano — Volcano Awareness Month 2022 Geonarrative

The seventh in a series of programs by HVO staff that will be posted on our website throughout the month of January. These programs are presented as...

Read Article
Volcano Watch — Learning from the 1984 eruption of Mauna Loa

Volcano Watch — Learning from the 1984 eruption of Mauna Loa

The most recent page in Mauna Loa’s eruptive history was written in 1984. The eruption began in March of 1984, about a decade after the 1975 summit...

Read Article
Volcano Watch — Remembering Mauna Loa’s eruption on July 5–6, 1975

Volcano Watch — Remembering Mauna Loa’s eruption on July 5–6, 1975

Mauna Loa erupted forty-six years ago this week, on July 5–6, 1975, in a 20-hour event with vents confined to the summit region (the area above 3,660...

Read Article
Volcano Watch — Tiny changes at Mauna Loa’s summit hold big clues

Volcano Watch — Tiny changes at Mauna Loa’s summit hold big clues

Although Mauna Loa is Earth’s largest active volcano, it has lived in the shadow of Kīlauea since it last erupted in 1984.  The geologic record shows...

Read Article
Volcano Watch — “By failing to prepare, you are preparing to fail.” – Benjamin Franklin

Volcano Watch — “By failing to prepare, you are preparing to fail.” – Benjamin Franklin

Mauna Loa has been in the news lately, as the volcano continues to awaken from its slumber. While an eruption of Mauna Loa is not imminent, now is the...

Read Article
Volcano Watch — When will Mauna Loa erupt next?

Volcano Watch — When will Mauna Loa erupt next?

“When will Mauna Loa erupt next?” This was the title of a Volcano Awareness Month video presentation released by the USGS Hawaiian Volcano Observatory...

Read Article
Volcano Awareness Month 2021 Program – When will Mauna Loa erupt next?

Volcano Awareness Month 2021 Program – When will Mauna Loa erupt next?

In this talk, USGS Hawaiian Volcano Observatory geologist Frank Trusdell, who has studied Mauna Loa for two decades, presents a roughly 40-minute talk...

Read Article
Volcano Watch — HVO looks to the past to better understand future Mauna Loa eruptions

Volcano Watch — HVO looks to the past to better understand future Mauna Loa eruptions

Mauna Loa, the largest active volcano on Earth, has erupted, on average, every 5–6 years during the past 3,000 years.

Read Article