Photograph by D.A. Swanson on December 15, 1999 Lava spills over sea cliff and oozes into the sea on southeast coast of Kilauea in Hawai`i Volcanoes National Park after flowing 11-12 km from the Pu`u `O`o cinder and spatter cone.

Lava erupted from Kilauea Volcano finally reached the sea again on December 13, three months after the supply of magma to the volcano's vent, the Pu`u `O`o cinder and spatter cone, was briefly shut off on September 12. Much to the delight of residents and visitors to Hawai`i Volcanoes National Park, lava is oozing into the sea about 1.5 km from the end of Chain of Craters Road, less than an hour's walk over an older pahoehoe lava flow (see map of flows, current as of December 14, 1999).

The 11-day pause in the eruption was the result of an intrusion of magma that occurred between Pu`u `O`o and Kilauea's summit caldera. Based on data from the deformation monitoring network on Kilauea, magma moved from both the summit area and from near Pu`u `O`o into the volcano's upper east rift zone. Preliminary analysis of the data suggests that 3-5 million m³ intruded into the rift zone (see details from the USGS Hawaiian Volcano Observatory).

When the pause in the eruption ended on September 23, lava re-entered the 11-km-long lava-tube system between Pu`u `O`o and the coast. Within less than 3 km from the vent, however, the tube was apparently blocked, because lava spilled out from several skylights and spread across the ground. Lava flows that developed from these skylights slowly formed new tubes that are currently supplying lava to the coastal plain.

The current eruption of Kilauea Volcano began on January 3, 1983, and ranks as the most voluminous outpouring of lava on the volcano's east rift zone in the past two centuries. There is no indication that the eruption is coming to a close.

September 25, 1999

Aerial view of lava lake in Pu`u `O`o two days after the end of a 12-day-long interruption in the supply of magma to the vent.

October 28, 1999

Lava pours through a lava tube on its way toward the coastal plain on the southeast coast of Kilauea Volcano; this skylight is the same one shown in the photograph below.

November 4, 1999

Aerial view of a lava-tube skylight (orange glow) and a pahoehoe flow (shiny surface around skylight) that poured from the tube.

Information About Hawaiian volcanism

| Kilauea eruption update | Update archive |

Current issue of Volcano Watch, a weekly essay written by USGS scientists.

Volcano and seismic hazards on the Big Island of Hawai`i, including explosions caused by lava entering the sea and collapses of new land built by lava flows.

Hawai`i Volcanoes National Park, home to HVO--find visitor information and resources here.