Images

A close-up of the active vent on the floor of Pu‘u ‘Ō‘ō crater.

A close-up of the spattering source on the floor of Pu‘u ‘Ō‘ō crater. A small spatter rampart has formed along the east side of the vent.

The 1940 cone, just above center, pokes up above the otherwise relatively flat floor of Moku‘āweoweo - the summit caldera of Mauna Loa. Mauna Kea rises up in the background.

View looking downslope at the various cones that dot Mauna Loa's Northeast Rift Zone. The edge of North Pit, on the north side of Moku‘āweoweo, is in the foreground.

Close-up of the 1949 cinder-and-spatter cone as seen from the floor of Moku‘āweoweo, Mauna Loa's summit caldera. pāhoehoe lava visible in the foreground (lower half of photo) was erupted in 1940. Beyond these flows, you can see pāhoehoe flows, spatter, and tephra erupted in 1949.

Aerial view of Mauna Loa's upper northeast rift zone near the area where it intersects Moku‘āweoweo, the summit caldera. Pāhoehoe flows visible in the foreground were erupted in 1942. Distant steep cliffs (right background) are the west wall of the summit caldera.

The 1949 cinder-and-spatter cone (left) and 1940 spatter cone (right) as seen from the floor of Mauna Loa's summit caldera, looking to the southwest. Pāhoehoe flows in the foreground were erupted in 1984.

This view of Mauna Loa's summit is looking toward the northeast. The east flank of Mauna Kea is to the left, and North Pit, on the northeast end of Moku‘āweoweo, is straight ahead.

The 1940 cinder-and-spatter cone as seen from the caldera floor looking to the southeast. This cone, which is about 114 m (373 feet) high, was built around the vent as lava spewed from it over a period of 134 days. The dark-colored pāhoehoe flows visible in the foreground were erupted in 1984.

A view of Moku‘āweoweo, the summit caldera of Mauna Loa, as seen from South Pit (looking to the north-northwest). An eruption in 1940 created the cinder-and-spatter cone visible on the caldera floor (right center). This cone, which is about 114 m (373 feet) high, is the largest cone at Mauna Loa's summit.

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.

The floor of Pu‘u ‘Ō‘ō crater continues its slow rise as lava pours out of a new vent at the base of the east wall. The height of the floor has risen 20 m (66 ft) over the past two weeks.

A low-angle view of the perched lava lake shows how it is elevated above the floor of the crater, like an above-ground swimming pool. The levee around the stands some 8-10 m (26-33 ft) above the surrounding crater floor. Also visible as the bottom of the photo is a new vent which began erupting around midnight last night on the western edge of the crater floor.

View looking up Mauna Loa's spectacular Southwest Rift Zone. Pu‘u o Keokeo fills the lower half of the photo. The black lava beyond is mostly from 1916 and 1926. The summit of Mauna Loa is in the background.

Sulfur, not snow, paints the ground white in the Sulfur Cone area on Mauna Loa's upper Southwest Rift Zone. The summit of Mauna Loa is over the slope of the mountain out of sight to the left in the background.

Shield-volcano Mauna Kea viewed from the northern slope of Mauna Loa (cinder cones in the foreground) shows off its broad shield shape. The bumps on its profile are large cinder cones.

The high point of Mauna Loa, in the background at an elevation of about 13,679 ft, is actually just the highest point along the rim of the steep cliffs that surround Mauna Loa's summit caldera, Moku‘āweoweo, Dark-colored lava flows of recent vintage (1984) cover the floor of Moku‘āweoweo. View is looking southwest.

This edge of the cliff above Moku‘āweoweo, at an elevation of 13,661 feet, is only a few feet lower than Mauna Loa's high point (out of sight to the left). The cliff here is about 600 feet high. Mauna Kea, in the background to the right rises to an elevation of 13,796 feet, barely 100 feet higher the summit of Mauna Loa.

This view of Mauna Loa's 1940 vent cone, looking to the southwest, shows a fissure that bisected it during the 1984 eruption (crack on the right side of the cone). Pāhoehoe flows and spatter erupted from the 1984 fissure blanket the caldera floor northwest of the cone (foreground).

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.

Aerial view of the perched lava lake in Pu‘u ‘Ō‘ō crater. Small fluctuations in the lava lake level lead to frequent overflows. These serve to build the levee around the lake even higher, amplifying the perched appearance.