Volcano Watch — Lava flows from two Pu‘u ‘O‘o vents

The eruption on Kīlauea's East Rift Zone continued through the week. Two vents were active, both located on the flanks of the 770-foot-high Pu`u `O`o cone.

The first of these is the episode 51 vent, which has been intermittently active for exactly one year. The second is the episode 53 vent, which began erupting on February 20. The lava fountains that were active during the first two days of episode 53 constructed a large, dome-shaped cone over the vent.

The vent is no longer fountaining, but lava intermittently overflows the top of the 53 cone and feeds small pahoehoe flows that extend only a few hundred yards from its base to the southwest. Not far from the 53 vent, this lava tube empties into a skylight in an older tube from the 51 vent. The two streams join and flow through the tube on the top of the pali. On the slope of the pali, flows have broken out of the old 51 tube to form new surface flows. Most of these flows are now roofed-over, forming new tubes.

For the most part, the new flows have remained on top of the Kamoamoa flow that entered the ocean from November until early February. The new flow reached the ocean on March 2 at the western edge of the Kamoamoa flow. By the 3rd, numerous small streams of lava were entering the ocean along a front about 500 feet wide.

Throughout the week, a small branch of the new flow crept toward the Chain of Craters Road well to the west of the main flow and threatens to cut the road just west of Lae`apuki, where the Kalapana Trail reaches the road. The active surface flows are visible from the end of the Chain of Craters Road in Hawai`i Volcanoes National Park.

The lava pond at the bottom of the crater in Pu`u `O`o remains active. The pond has resumed the dimensions it had before the collapse of the crater floor on the night of Feb. 8 and is about 250 feet in diameter. The crater floor is now about 190 feet below the lowest point on the crater rim. For the last week, the level of active lava in the pond has fluctuated by approximately 30 feet, so that sometimes the surface of the pond is below the crater floor and at other times the pond overflows onto the crater floor and coats it with a fresh sheet of pahoehoe.

There were no earthquakes of magnitude 3 or greater on the island during the last week.