Images

This aerial view of Mauna Loa's summit shows the cinder-cone and lava flows that were erupted in 1949. The crack extending down the left side of the cone is the northeast-southwest trending 1984 fissure that bisected the southwest flank of the cone during the initial phase of the eruption. Light-brown tephra erupted from the 1949 cone thins to the west.

An aerial view of the 1940 cinder-and-spatter cone on the floor of Mauna Loa's summit caldera as seen from the southeast. The west wall of the caldera (background) is about 170 m (560 feet) high. Most of the caldera floor around the cone is covered by lava flows erupted in 1984.

Solar-powered seismic station located near the summit of Mauna Loa Volcano, Hawai‘i.

On July 6, 1975, eruptive fissures opened along Mauna Loa

Lava fountains up to 20 m (65 ft) high erupted from fissures on the north flank of Mauna Loa early Sunday morning, July 6, 1975. USGS photo.

Lava fountains erupt from a fissure in the southwestern part of Moku`aeoweo, Mauna Loa's summit caldera, on April 11, 1940 (view looking to the south-southeast). Patches of white snow cling to the caldera walls as fluid pahoehoe lava flows spread across

Maps showing lava flow progression during the 1984 eruption of Mauna Loa. These maps were featured in the Hawai‘i Tribune-Herald newspaper on March 27, 1984 (top) and March 30, 1984 (bottom). 

Lava production from these "2,900-m vents" began to decrease in late March but declined most rapidly between April 7 and 9 from about 300,000 m3 per hour to less than 100,000 m3 per hour. Photo taken at 9:09 a.m.

Lava flows from the 1984 eruption of Mauna Loa loom above the town of Hilo. Photograph taken near the Hilo airport on April 4.

Pohaku Hanalei cinder-spatter cone (upper left) is located about 3.2 km (2 mi) NE from the north edge of the caldera rim. Eruption rates were as high as 2.9 million m3 per hour during the first 6 hours of the eruption, then diminished to about 0.5 million m3 per hour for the next 12 days.

Aa lava flows erupting from Mauna Loa.

(Left) Aerial photograph of the Pāhala area, on the southern side of the Island of Hawaiʻi, taken on December 11, 1976. (Right) The backside of the same photo showing labeled field locations, marked with a pinhole through the photograph, which correspond to the geologist’s field notes. 

Mauna Loa 1975 eruption. Lava fountains up to 20 m (65 ft) high erupted from fissures on the north flank of the volcano early Sunday morning, July 6, 1975.

The Ka‘apuna flow traveled from the Southwest Rift Zone vent (7,800 ft elevation) to the coast in just 17 hours.

Photograph taken from sea aboard a ship.

Fissure of lava fountains erupting from Mauna Loa's upper southwest rift zone, June 2, 1950. Plumes of volcanic gas rise high into the air. Aerial photograph taken by the Air National Guard.

Aerial photograph shows the Ka‘apuna lava flow erupted from Mauna Loa in 1950 as it advanced through the forest at about 3,000 feet elevation on the morning of June 2. This rapidly moving ‘a‘ā lava flow traveled from the Southwest Rift Zone vent to the ocean in about 17 hours. Earlier flows from this same eruption reached the ocean in as little as three hours.

Aerial photograph of the 1942 Mauna Loa lava flow spreading downslope toward Hilo; smoke from burning trees in center of flow. Scattered cinder cones at the summit of Mauna Kea, top of photograph.

Aerial view by the Naval Air Service of the 1933 Mauna Loa eruption from a fissure across the rim and floor of Moku‘āweoweo Crater.

Scientists looking into the bright glow of Mauna Loa's 1942 eruptive vent. Eruption occurred during WWII and was not publicized to prevent Japanese war planes from navigating to the island at night.

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.