Images

A close-up view of the 1984 fissure that cut through the southwest side of Mauna Loa's 1940 vent cone. The crack on the right side of the cone is the 1984 fissure.

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.

Controlled burn at Okefenokee National Wildlife Refuge.

USGS employees deploys a water conductivity/temperature/depth probe (AquaTroll) for a temporary study along the Madison River, Yellowstone.

USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions. One floodgate on the Morganza Spillway was opened on May 14, 2011. 

This photo was taken before one of the floodgates on the Morganza Spillway was opened on May 14, 2011. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions.

Floodwaters rise upstream of the Bonnet Carre Spillway near Norco, La. The Army Corps of Engineers uses USGS streamflow data to help them manage flood control structures.

USGS scientist Errol Meche installs a temporary streamgage to measure water levels above and below the the Morganza Spillway. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions. One floodgate on the Morganza Spillway was opened on May 14, 2011.

USGS scientists Todd Baumann and Errol Meche install a temporary streamgage to measure water levels above and below the the Morganza Spillway. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions. One floodgate on the Morganza Spillway was opened on May 14, 2011.

USGS scientists Todd Baumann and Errol Meche install a temporary streamgage to measure water levels above and below the the Morganza Spillway. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions. One floodgate on the Morganza Spillway was opened on May 14, 2011.

USGS scientists Todd Baumann and Errol Meche install a temporary streamgage to measure water levels above and below the the Morganza Spillway. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions. One floodgate on the Morganza Spillway was opened on May 14, 2011.

One floodgate on the Morganza Spillway was opened on May 14, 2011. USGS streamflow information is used by the U.S. Army Corps of Engineers to help them make informed flood management decisions.

USGS scientists take streamflow and water quality measurements downstream of the Bonnet Carre Spillway near Norco, La. The Army Corps of Engineers uses USGS streamflow data to help them manage flood control structures.