bob@uhmanoa.UUCP (Bob Cunningham) (01/06/88)
[portions of this note stolen from recent local newspaper articles by Jim Borg and Hugh Clark, along with 1st & 2nd-hand observations of various other people.] Kilauea volcano, on the island of Hawaii, has been in eruption now for five years. Here's a brief list of some of the significant events: 1983. Eruption starts at Napau Crater on Kilauea's east rift zone in Hawaii Volcanoes National Park on 12:31am, 3 Jan 1983. Eruption very episodic in 1983. 15 dwellings destroyed (first house losses since Kapoho eruption of 1960), 170 house lots overrun, miles of roadway covered. Vegetable and flower growers suffered major crop losses the fallout (like intense acid rain). Residents from Waikiki (on Oahu) to Kona and Hilo (on the Big Island) suffer from several episodes of sulfur-intensive volcano haze. Eruption produces spectacular fountaining, with some night-time gaseous outbursts reachings heights over 1,000', mostly at Pu'u Kamomoa. 1984. 2nd year of Kilauea eruption almost "takes a back seat" to 22-day eruption of Mauna Loa that threatens Hilo (first simultaneous Kilauea/Mauna Loa eruption since 1868). Numerous spectacular fountaining events to heights of 2,000' at Pu'u O'o vent that develops into a giant mound on the rift zone upslope from Kalapana. Damage by lava during year limited to several dozen acres of ohia trees and three weekend cabins destroyed in the Puna Forest Reserve. 1985. Eruption continues, activity episodic and generally less active, though phase 30 on 4 Feb spreads a heavy fallout about 1" deep of pumice and "Pele's hair" (spun glass fibers) over most of Puna and Hilo. Fountaining at Pu'u O'o to 1,350' in November. As of December 1985, the first 35 months of the eruption had produced 450 million cubic meters (585 million cubic yards) of lava---the greatest volume of active lava "that modern instruments anywhere have recorded". 1986. For first half of year, eruption continues to stage short (9 to 20-hour) fountaining events about every four weeks with 1,000' or higher fountains. In July, new phase begins at Pu'u O' vent that spreads to cracks opening up almost two miles east at what later becomes a new vent. Extensive lava flows enter home site areas starting Thanksgiving eve as the (continuing to current date) 48th phase of eruption begins. Twenty-eight homes destroyed in three weeks. From then until now, the vent (previously called just "C Vent", but recently christened Kupaianaha ["mysterious hill"]) has continually poured out about 500,000 cubic meters (roughly 650,000 cubic yards) of lava a day. 1987. Virtually continuous Kupaianaha-based eruption, with lava lake developing around that vent. Between Thanksgiving 1986 to now, 42 homes destroyed. Lava criss-crosses federal, state and private roadways. Vog (sulfur-rich volcanic smoke) beseiges entire Big Island periodically, water supplies for the many Big Island residents using catchment systems fouled. Queen's Bath and blow hole near Kupapau Point obliterated. Father Damien's stone church inundated (finally covered up on 3 Jan 1988). As of yesterday, two more homes in Kapa'ahu Homesteads are threatened, and more of the Kalapana Bypass Highway (aka Highway 130) has been covered, forcing police to move their barricades eastwards. Three lava flows are still going into the ocean on the eastern side of Hawaii Volcanoes National Park and at a spot inside the park west of Kupapau Point. Lava has been flowing into the ocean continuously for nearly three months now. Bad weather keeps delaying photo recon flights over the shorline which will measure extent of new shore, but current estimate is that 45 acres or so have been added to the Big Island over the course of the eruption (most of that within the last 18 months). In retrospect, the most impressive aspect of the five years of eruption is the sheer output of lava, over 1 billion cubic meters (1.2 billion cubic yards). If that lava were spread 1' thick on a two-lane highway (12' per lane), the highway would reach the 240,000 miles to the Moon (or, circle the Earth's equator 10 times). Taking into account the extent of the whole Hawaiian island chain, it could have been built up over 70 million years with an average rate of only 20 million cubic meters per year---1/10th Kilauea's current output. For decades, Kilauea's output has always seemed to be much less than Mauna Loa---whose eruptions are less frequent, but seemed to produce much more lava (the 1 June 1950 Mauna Loa eruption, which lasted less than a day, produced 440 million cubic meters of lava). Now, it seems that Kilauea is indeed capable of a sustained eruption producing a considerable, cumulative amount of lava. And that's just what we can see and measure on the top of the island. The bulk of Kilauea, and the rest of the Big Island extends down to the bottom of the Pacific, below the ocean. Only last year have extensive undersea flows been discovered (by USGS survey ships) at the base of the east rift zone, in the depths at the base of Kilauea. -- Bob Cunningham bob@loihi.hig.hawaii.edu