1995 January		Collapse pits develop on the west flank of Pu`u`O`o cone.
1997 January		Lava fissure erupts in and northeast of Napau Crater on January 30, 1997, during episode 54. Five closely spaced fissures were active during the 22-hour episode.
1997 January		Fume rises from eruptive fissures within and just outside Napau Crater during episode 54. Pu`u `O`o cone is visible at top of photograph.
1997 January		Just before the fissures of episode 54 erupted, the lava pond in Pu`u` `O`o drained as magma was diverted to the area beneath Napau Crater. The west rim of Pu`u `O`o collapsed to form a notch 150-200 m wide and 75-100 m deep.

Changing views of Pu`u` O`o June 1992 August 1997 October 1999 Views looking eastward show changes to the west flank of Pu`u `O`o resulting from (1) growth of a shield at the base of the cone; and (2) several collapses on the cone and shield from 1995 to 1999. The most dramatic collapse occurred in late January 1997, when magma withdrew from beneath Pu`u `O`o to feed a fissure in nearby Napau Crater during eruptive episode 54.

March 1994 June 1997 Views looking northward show the results of the collapse of the Pu`u `O`o summit and west flank. The south flank of the cone changed significantly beginning in late 1997, when it collapsed to form the pit, Puka Nui (see below).

1997 April		Lava erupted outside Pu`u `O`o beginning on March 28, 1997, from a small pit at the base of the southwest flank (arrow); this episode 55 vent quickly built a small cone (images below). A few weeks later, another vent became active (circle) and fed a series of short flows for about 3 weeks.
1997 April		This spatter cone marks the site of the episode 55 vent, which became active on March 28, 1997. Other spatter cones were built in this area as the vent location changed through early June.
1997 June		A vigorous new vent began erupting on June 4, 1997, slightly northwest of the original episode 55 cone and the May 12 cone. This new vent eventually built a cone that covered the old episode 55 cone.
1997 October		Lava overflowed the crater of Pu`u `O`o several times between June 16 and October 18, 1997, coating both the west and northeast (lower left) flanks of the cone with pahoehoe. Note active vent in west end of crater.
1997 December to 1998 November		A large new pit, named Puka Nui ("large hole" in Hawaiian), developed on the south flank of Pu`u `O`o in late 1997 (top) and enlarged through 1998 (bottom). By the end of 1999, Puka Nui had nearly intersected the south  rim of Pu`u `O`o.
1998 May		During a temporary pause in the supply of magma to Pu`u `O`o on May 19-20, 1998, lava drained out of the tube system and stopped flowing into the ocean at the Waha`ula and Kamokuna entry points. As lava re-entered the tube system on the evening of May 20, several breakouts occurred along the length of the tube.
1998 May		View into skylight shows lava cascading down a steep slope.
1998 September		The shiny surface of new pahoehoe marks the pathway of lava that reached the sea a few weeks after a 2-3 day eruptive pause in August 1998.

More information about the eruption

• Eruption narrative
• Map of Pu`u `O`o and area covered by lava
• Table of eruption statistics
• Current Eruption Update (updated frequently)

More Photographs of Eruption Summary

• 1983-1986, The rise of Pu`u `O`o: episodic lava fountains build massive cone
• 1986-1991, Eruption shifts to Kupaianaha: continuous effusion sends lava to the sea
• 1992-1994, Eruption returns to Pu`u `O`o: flank vents build shield against uprift side of cone
• 1999-2000, Intrusion triggers pause in eruption: tube system blocked