Volcano Watch — Kīlauea eruption status

The eruption along Kīlauea's East Rift Zone continues with little change. Based on changes in instrumental readings recorded at the Observatory, brief pause in activity began about mid-afternoon on December 14 and lasted until midnight on December 15. The amount of lava entering the ocean along the east side of the currently active flow field did not diminish until mid-afternoon on December 15 and did not stop until the morning of December 16. As activity picked up, lava reoccupied the existing tube system all the way to the ocean.

Our ability to frequently observe the activity was curtailed severely during the next three weeks during the shutdown of the Federal government, but our skeleton crew kept track of changes through observations and reports from local helicopter pilots and from the fire crews from the National Park Service. We sincerely appreciate their efforts on our behalf.

After the eruption resumed on December 16, numerous surface flows broke out of the tube system at about the 2,250-foot skylight and the 1,900-foot level. Additional flows broke out below the 1,000-foot level and covered previously uncovered ground along the eastern side of the flow field. These flows ignited several brush and grass fires, which, due to Kona wind conditions, pushed eastward through the large kipuka that includes the remaining parts of the Royal Gardens Subdivision.

The lava pond inside the Pu'u 'O'o cone continues to fluctuate in depth. Prior to the pause on December 14, lava was no longer visible from our normal vantage point on the rim. After the pause was over, lava had risen by at least 75 feet and again formed a large active lava pond about 225 feet below the lowest point on the rim. By January 9, Kona winds made it impossible to see the pond level through the thick fume.

Several changes have taken place during this long interval, in addition to the pause in activity discussed above. The most dramatic change was a period of intense explosive activity at the Kamokuna entry that took place on January 1 following a major bench collapse. The lava bench that slid into the ocean was at least 170-230 feet by 650-1000 feet. This was the third major collapse in this area since mid-October.

The area continues to be unstable and will likely be the site of additional bench collapses if lava continues to enter the ocean at the same entry. The explosive activity included a series of bubble bursts, and spatter and tephra were ejected to heights up to 200 feet. These explosions built a new littoral cone at the shoreline to replace the several that were destroyed when the bench slid away.

A second change is that lava was observed in the bottom of a collapse pit on the west flank of Pu'u 'O'o. This collapse pit has been the site of heavy fuming for many months, but we had not previously been able to see lava at the bottom of the pit. This pit, as well as others on the flanks of Pu'u 'O'o, continue to enlarge due to undercutting of the cone.

The active flows will probably continue to enter the ocean near Kamokuna on the east side of the flow field until another pause takes place. Even then, lava may return down the same tube, as it did after the pause on December 14.

Lava viewing at the end of Chain of Craters Road inside Hawaii Volcanoes National Park is from a distance of more than two miles because of the long and hazardous hike across the flow field. From the Kalapana side of the flow field, the lava entry is more than five miles from the end of the road. Access to the Kalapana area beyond the end of the highway continues to be restricted by Hawai'i County Civil Defense.