3 February 2000
Flow reaches ocean near Waha`ula
Glow visible from Pu`u `O`o vents
14 February 2000
Two ocean entries: Lae`apuki still active, Waha`ula starting up
Lava continues to flow steadily into the sea at the Lae`apuki bench. A second ocean entry became active on February 3, when lava began to dribble over the sea cliff at Waha`ula, 4 km east of Lae`apuki. This new ocean entry is located along the east margin of lava flows that were active from July 1997 to late 1998. In the past several days, lava has poured over the cliff intermittently, and a small bench is beginning to form at the base of the cliff.
Main pathways of lava descending Pulama pali
Since mid-October 1999, lava flows have advanced down Pulama pali over an area several kilometers wide, covering earlier flows and spreading through several kipuka. Two main lava tubes have developed within these flows and are now supplying lava to the Lae`apuki lava bench and to the wide flow field that has covered the private access road to Royal Gardens subdivision and the newly active Waha`ula entry area.
Collapse pits on south shield of Pu`u `O`o
23 February 2000
Seismic swarm and ground deformation occurs along upper east rift zone
A swarm of shallow earthquakes began on Kilauea's upper east rift zone at 1342 this afternoon. The swarm is centered near Pauahi Crater, located about 7 km southeast of Halema`uma`u Crater along the Chain of Craters Road. Tiltmeters just east of Pauahi and at Pu`u `O`o both recorded changes related to the swarm, as did tiltmeters at Kilauea's summit.
The swarm is probably recording the movement of magma intruding to within 1-2 km of the ground surface. Such swarms commonly precede new fissure eruptions, but they more often record intrusions rather than eruptions. No new ground cracks have been noted. Gas geochemists are measuring the flux of certain gases in the area in an attempt to determine if magma is indeed near the surface.
As a precautionary move, the Hawai`i Volcanoes National Park closed the Chain of Craters Road to all visitors. By 1730 the swarm appeared to be tapering off, but we are remaining vigilant, and the Park will keep the road closed overnight (the road was reopened at 7:30 a.m. on February 24).
24 February 2000
Breakouts result from tube blockages
The intrusion of magma into the upper east rift zone of Kilauea on February 23 caused minor but noticeable changes in the ongoing eruption. Lava continued to enter the tube system at Pu`u `O`o, but blockages in the tube above the pali resulted in many breakouts on the active flow field.
During the afternoon of February 24, pahoehoe broke out from a tube in the West flow 200-300 m upslope from the area of the photographs below. The pahoehoe sped down the steep ground surface, transforming into `a`a as it moved. When the photographs below were taken, the `a`a was advancing at a rate of 1 m per minute or faster, burning and bulldozing its way through `ohi`a forest at the edge of a kipuka separating the West and Smoke flows.
Tilt of ground at summit marks Feb. 23 intrusion into east rift zone
The intrusion began at 1:42 p.m. HST when tiltmeters at the summit showed a downward tilt of the ground (red line) toward the caldera. A swarm of small earthquakes along the upper rift zone accompanied the ground deformation. The downward tilt indicates that magma was moving out of the summit reservoir; data from two other tiltmeters on the east rift zone indicate the magma was moving into the rift zone. The reversal of the summit tilt a few hours later indicates when the intrusion stopped and magma once again moved into the summit reservoir.
27 February 2000
Lae`apuki ocean entry active on east side
Late this morning, lava was oozing into the sea along a wide front on the eastern part of the Lae`apuki lava bench. At about noon, a small surface flow spilled from a lava tube at the apex of the sea cliff and the bench, forming a slow-moving pahoehoe flow on the bench.
Map of lava flows from Pu`u `O`o to the ocean
Large map. Map shows lava flows (pink) on Pulama pali and coastal plain active since 23 September 1999 and flows erupted earlier from Pu`u `O`o and Kupaianaha. Lava reached the ocean at the Lae`apuki bench 17-18 December 1999. The eastern part of the active flow field reached the Royal Gardens private access road (blue dashed line) on January 11 and the sea on February 3.
Eruption-viewing opportunities change constantly, so those readers planning a visit to the volcano should contact Hawai`i Volcanoes National Park for the most current eruption information (tel. 808-985-6000).
Updated: 6 June 2000 (SRB and DAS)