(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

At 1:42 p.m. Saturday, March 5, seismic tremor at Kilauea abruptly increased. This was followed by the rapid deflation of Kilauea’s east rift zone near Puu Oo.

In response, the floor of Puu Oo crater composed of lava flows emplaced over the past several months, rapidly subsided, eventually dropping about 115 m (377 ft). Just after 5 p.m., a fissure opened west-southwest of Puu Oo within Hawaii Volcanoes National Park, and began erupting lava.

The fissure continued to lengthen and erupt lava sporadically through March 6; but by the following day activity had begun to focus at the eastern and western tips of the fissure. Spatter cones up to 15 m high were constructed by low fountains that tossed lava as much as 50 m (164 ft) above the vents.

The eastern vent stopped erupting March 8, but a channelized lava flow from the western vent advanced about 2.9 km (1.8 miles) down slope before stalling March 9. As of 10:30 p.m. March 9, activity at the western vent had stopped, and no lava was being erupted anywhere on Kilauea’s east rift zone.

Kilauea’s summit also began to deflate with the onset of seismic tremor on March 5, and the lava lake at Kilauea’s summit, which had been about 70 m (230 ft) below the floor of Halemaumau, began to drop slowly.

By the following day, the lava surface had receded to a depth estimated at about 220 m (722 ft) below the Halemaumau Crater floor. Accompanying these changes, volcanic gas emissions increased and remain elevated, resulting in high concentrations of sulfur dioxide downwind.

At least 10 earthquakes beneath Hawaii Island were reported felt this past week.

A magnitude-2.4 earthquake occurred at 4:27 p.m. Thursday, March 3 and was located 5 km (3 mi) south of Volcano Village at a depth of 5 km (3 mi).

A magnitude-2.8 earthquake occurred at 5:15 a.m. Saturday, March 5, and was located 8 km (5 mi) northeast of Kukuihaele at a depth of 6 km (4 mi).

A magnitude-2.2 earthquake occurred at 4:56 p.m. Saturday and was located 7 km (4 mi) southwest of Puu Oo Crater.

Seven earthquakes with magnitudes ranging from 1.9 to 3.1 occurred between 10:53 p.m. Saturday, March 5 and 1:25 a.m. Tuesday, March 8, and were all located in the Kilauea summit area at a depth of 2 km (1 mi).