Pu'u O'O: 9/18/97 Aerial view SW	Pu'u O'O: 9/18/97 Aerial view WSW	Lava entering the sea.	Lava bench along the coast

Kilauea's 15-year-long eruption continues to exhibit the kind of activity that has made it the most destructive Hawaiian eruption of the last two centuries and the volcano one of the most popular destinations in the world. Every day more than 500,000 cubic meters of lava pour from Pu'u O'o, Kilauea's active vent, into lava tubes; much of this lava enters the ocean 12 km away. Lava flows no longer threaten communities on the south coast of Kilauea as they did several years ago (anchor "communities" to Kalapana section), but people continue to walk across potentially dangerous areas where lava enters the ocean and creates new unstable land. At Pu'u O'o, between 1,000 and 2,000 tons of sulfur dioxide gas are discharged into the atmosphere daily. Consequently, Hawaii's residents remain concerned about the potential long-term health effects of the resulting volcanic air pollution known locally as vog.

Of particular interest to scientists, but less apparent to visitors and many residents, is activity taking place within the volcano itself. In the past few months, two swarms of earthquakes occurred beneath Kilauea's caldera and along its west flank. Also, two earthquakes of magnitude 5.3 and 4.5 struck beneath Kilauea's south flank--a part of which is moving seaward at the relatively high rate of at least 15 cm per year. What this means in terms of the future is conjectural, but the continued seismic activity and ground movement illustrate the inherent instability of Kilauea.

Activity at the Pu`u `O`o vent is even more intriguing. Since June, 1997, lava has poured intermittently from a small cone within Pu'u O'o, sometimes filling its crater to overflowing and other times disappearing as it drains into fractures, perhaps reappearing in a vent only 500 m farther south. This southern vent feeds most of the lava into the tubes and eventually to thesea. The details of Pu'u O'o's shallow plumbing system remain subjects of considerable discussion. They are of particular interest relative to the potential development of a large, deep pit crater centered on Pu'u O'o, especially as arcuate fractures appear sporadically on its flanks.