July 29, 2010
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
"Kalapana Gardens home lost to lava, 2nd periled"
Most readers will see the headline and think it refers to events in Kalapana this past week. The title is actually from a back page story in the Honolulu Advertiser, August 15, 1990, issue. D?j? vu.
Kalapana Gardens, also known as Kalapana Vacation Lots on the internet, was founded in the 1960s and boasted 120 homes on 739 lots in early 1990. In 1991, the home total was zero, because the subdivision was completely overrun by lava flows from Kupaianaha. The destruction took place over an 11-month period, but by August, most of the homes were already destroyed along with Walter's Kalapana Store and Drive Inn (with the oldest water well in Puna), the Star of the Sea church, Harry K. Brown County Park, Kaimu Bay and famed black sand beach, and a well-known surf spot called Drainpipes.
The 1990 lavas were unusually destructive because their path to the ocean was blocked by the Hakuma horst, an uplifted fault block that paralleled the coast. The horst formed a natural barrier that diverted flows laterally through the subdivision thereby sealing its fate. Flows built up along the north edge of the horst so that, by 1991, the horst was only a few meters (yards) higher than the top of the flows.
The lava flows might have continued eastward, destroying more of the neighboring community in Kaimu, but lava was progressively fed into flows advancing westward away from Kaimu. The Kalapana flows were inactive by February 1991. A year later, the erupting vent changed location back to Pu`u `Ō `ō, farther to the west.
For many years afterward, lava activity remained to the west, inundating areas within Hawai'i Volcanoes National Park. The lush, vegetated landscape that had been Kalapana became barren pahoehoe lava. It was such a dramatic, stark landscape that the opening sequence to the remake of "Planet of the Apes" was filmed at its edges in 2000-2001. A few years later, the subdivision was resurveyed, real-estate activity picked up, and people started to rebuild.
In 2007, a new vent opened east of Pu`u `Ō `ō to a location near Kupaianaha. This brought flowing lava back towards Kalapana. In 2008, lava on its way to the ocean destroyed the few structures that had been built on 2002 lavas just west of Kalapana. A few tube disruptions later, and lava is now heading back into Kalapana Gardens subdivision which, in 2010, is comprised of about 35 structures.
Currently, the flows have slowed, possibly due to a temporary decrease in the supply of lava from the vent. The future of the reborn Kalapana Gardens is far from clear.
The future of two HVO staff members is, sadly, much clearer. After serving HVO for more than 40 years, senior electronics technician Ken Honma retired this week. Ken has taken part in some extraordinary efforts around the Pacific and has had a tremendous impact on HVO. Details of his long and productive career will be in next week's column.
Seismic network manager Dave Wilson also left this week for his new assignment at the Albuquerque Seismological Laboratory in New Mexico. Dave started at HVO a few months after the damaging Kiholo Bay-Mahukona earthquakes in 2006. He also worked through the Father's Day intrusion, the filling and splitting of Pu`u `Ō `ō in 2007, and marveled at the opening of the Halema`uma`u vent in 2008.
Dave spent most of his time at HVO upgrading seismic data processing software which now offers many more capabilities and takes full advantage of the instrument upgrades funded by the American Reinvestment and Recovery Act of 2009. As a parting gift, Dave this week has added a link to our Recent Earthquakes webpage that produces six select helicorder records from our seismic network.
We wish Ken and Dave the best futures imaginable and we also hope that Kalapana Gardens doesn't get covered twice by flows from the same eruption.
Kīlauea Activity Update
Over the past week, surface flows continued to be active in two areas on the coastal plain. As of Thursday, July 29, surface flows had breached the Hakuma horst fault scarp in several areas, creating many small fires and smoke plumes. Two flows, about 550 m (600 yards) apart, made it to the ocean and are producing small ocean entries. The flows on the coastal plain are still advancing to the east near Kalapana Gardens, slowly filling in the low areas. Upslope, approximately 1 km (0.6 miles) above Highway 130, minor activity continues as the lava flows through the remaining vegetation. Repeated deflation/inflation (DI) events at Kīlauea's summit, ongoing for the last several days, may cause the surface flows on the coastal plain to stall and restart repeatedly.
At Kīlauea's summit, a circulating lava pond deep in the collapse pit within the floor of Halema`uma`u Crater was visible via the Webcam throughout the past week. The baseline lava level was punctuated sporadically by short-lived lava-level increases. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.
One earthquake beneath Hawai`i Island was reported felt during the past week. A magnitude-2.2 earthquake occurred at 1:42 a.m. on Thursday, July 29, 2010, H.s.t., and was located 7 km (4 mi) northeast of Honoka`a at a depth of 30 km (19 mi).
Visit our Web site (http://hvo.wr.usgs.gov) for detailed Kīlauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kīlauea activity summary; email questions to askHVO@usgs.gov.
Updated: August 18, 2010 (pnf)