Previous Pu`u `O`o Eruption Episodes of Kilauea Volcano
(episode 54 - Napau Crater)

Lava flows from episode 54 fissure E in Napau Crater came right up to the edge of the forest. Photo taken by Ken Rubin on 24 May 1997, some 4 months after the eruption.

30 Jan-17 Feb 1997: Activity initiates and then dies at Napau Crater -- then Kilauea goes silent
Is this the end of the 14-year long Pu`u `O`o eruption?

This page contains update information from Episode 54 of the Pu`u `O`o eruption of Kilauea Volcano. Please see the eruption update page for more recent activity at Kilauea, including the second half of Episode 55

    The newest episode of activity of the Pu`u `O`o eruption began on Jan. 30 at about 2:43 AM in Napau Crater, about 4 km uprift from the main site of venting over the last 5 years at the Pu`u `O`o cone. The "Pu`u `O`o" eruption originally started in 1983 at Napau Crater and has now returned to this site. This newest event is being called "episode 54" by the staff of HVO. This area of Kilauea is fairly remote, so we are fortunate to have reports from campers near the area, who heard hissing sounds and saw an orange glow from the crater, helping to establish the time of the start of the eruption. Below is a chronology of events in this new phase of activity. You will also find maps of Napau Crater showing the new lava flows and a map of Kilauea's East Rift Zone giving the spatial relationship between this and previous activity in the Pu`u `O`o eruption.

Precursor events: Jan 29.
   Harmonic tremor was recorded on seismograph near the new eruption site for ~7 1/2 hours. The tremor was accompanied by deflation of the summit of Kilauea (17 microradians), which lasted about 8 hours. Deflation of the summit has continued to 21 microradians. This large deflation of the summit magma reservoir is thought to indicate that a large volume of magma has been intruded into the east rift zone of the volcano to fed this eruption.
    FIG. 1 Napau crater is shown in the image below. The orange areas represent very recent flow activity, with letters A-F indicating individual short-lived vents from which lava poured.

The eruption:
   Jan 30

• 2:43 AM- Three fissures (A, B and C on the figure) form within and just east of the crater producing lava fountains a 10's m high.
• 7:16 AM- All three fissures stop producing lava but continue spattering intermittently. The flows from these fissures have covered 48 acres.
• 12:39 PM- A new fissure (D) forms just east of fissure C and produces a new flow.
• 4:39 PM- Another fissure (E) forms just east of fissure D and also produces a flow.
• 6:40 PM; fountaining has stopped at fissure D and E but harmonic tremor continues. Total acres covered by the flows from these two vents is only 14.5.
• 8:43 PM- fountaining resume on a new fissure (F) on the west rim of Napau crater.

• 12:33 AM- Fountaining stops at the F fissure; 3 acres are covered by the flow from this fissure.
• 7:00 AM- The Pu`u `O`o eruption is quiet for now but it is expected to restart at anytime. The backcountry to the eruption site has been closed by the National Park Service as has the chain of craters road. HVO and National Park Service staff anxiously await the next movements of Pele.

• Reports from the field indicate no new lava flow activity or spattering from the new vents.
• Seismicity at the eruption site has returned to background levels and deflation of the summit has stopped.
• Gas samples were collected from the episode 54 vents and the location of the new flow margins and fissures were mapped by the HVO staff today.
• Officially, episode 54 of the Pu`u `O`o eruption is over (all 'pau' in Hawaiian). However, a large volume of magma was intruded during episode 54 from the summit of Kilauea into the east rift zone based on a deflation of the summit of about 30 microradian. It has been estimated that a microradian might represent ~330,000 cubic meters of magma (Dzurisin et al., 1984, J. Vol. Geotherm. Res., v. 21, 1994). Thus, about 10 million cubic meters of magma may have been intruded into the rift during episode 54. This is about a month's supply of magma given the typical eruption rate for the Pu`u `O`o eruption.

• An uneasy quiet remains as we await the next episode of this 14 year eruption. Signs indicate that the rift zone is re-inflating, so a renewed surface eruption is not out of the possibility. However, whether it re-occupies the Pu`u `O`o vent, the short-lived Napau Crater vent, a different vent, or even a new vent is something volcanologists at Kilauea are hesitant to speculate about. Time will tell.

• The volcano is still quiet. Scientists haven't given up hope for a renewal of activity at Kilauea but the prospect grows dimmer with each passing week of inactivity. On the bright side, the Honolulu newspaper reported yesteday that air quality on the Kona side of the Big Island has improved drastically. The volcano's output of noxious SO2 gas has decreased by a factor of 10 since the volcano went quiet (from about 200,000 lbs/day to about 20,000 lbs/day). It has been estimated that during the Pu`u `O`o eruption, Kilauea hs been the largest point source of atmospheric contamination in Hawaii.
  
  Photo of low fountains and volcanic fume from fissue E in Napau Crater during episode 54. Photo taken from the air on Jan. 30, 1997 by Laszlo Keszthelyi. Used with permission of the U. S. Geological Survey's Hawaiian Volcano Observatory.

What about the Pu`u `O`o Vent?
    While this activity was occurring at Napau crater, the Pu`u `O`o cone was collapsing and the crater within it became ~100 m deeper. By 11 AM, the crater was ~200 m below the rim of the cone and was continuing to collapse, producing plumes of red dust that rose 800 m into the air in the process. Lava has stopped moving through the lava tube downhill from the Pu`u `O`o cone.

Jan-Feb 1997, Recent Activity at Kilauea

1. Don Swanson
2. Carl Thornber
3. Dave Sherrod
4. Frank Trusdale
5. James Kauahikaua
6. Laszlo Keszthelyi

This page created and maintained by Ken Rubin©, krubin@soest.hawaii.edu
Other credits for this web site.

Last page update on 23 Mar 1998