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. Photo courtesy of USGS/HVO

(Volcano Watch is a weekly article and activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

Lava erupted continuously within Pu`u `O`o over the past week, feeding a small lava lake in the center of the crater. Changes in eruptive output commonly resulted in overflows from the lake that slowly built up the crater floor, which is about 70 m (230 ft) below the east rim of Pu`u `O`o. No lava is erupting outside the 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.

A small, stable lava lake was also present deep within the Halema`uma`u Overlook vent during the past week. Volcanic gas emissions remain elevated, resulting in relatively high concentrations of sulfur dioxide downwind.

One earthquake beneath Hawai`i Island was reported felt this past week. A magnitude-2.3 earthquake occurred at 6:51 p.m. HST on Monday, May 2, 2011, and was located 6 km (4 mi) south of Holualoa at a depth of 11 km (7 mi).

Visit the HVO Web site (http://hvo.wr.usgs.gov) for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov