Volcano Watch — Royal Gardens in Kīlauea's crosshairs again

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If you follow HVO's daily updates on Kīlauea's east rift zone eruption, you are likely aware that the few remaining kipuka in the Royal Gardens subdivision are, at this moment, being devoured slowly by advancing lava flows.

Royal Gardens in Kīlauea's crosshairs again...

Lava flows creep through the Royal Gardens subdivision on February 24, 2012, slowly burying the few remaining forested kipuka.

(Public domain.)

On March 2, the last occupied house—protected for decades by a large ‘a‘ā flow that repeatedly diverted subsequent flows away from it—was finally consumed by lava. Overgrown remnants of a few streets, and one small abandoned house, are the only testaments to what was there before. The feel of a ghost town is heavy in the air.

In some ways, though, it's surprising that Royal Gardens has lasted this long. Subdivided speculatively in the early 1960s, few of the more than 1,800 house lots had been developed by the early 1980s. When ‘a‘ā flows from Pu‘u ‘Ō‘ō started to invade the upper part of the subdivision in 1983, 22 houses—about a third of those constructed at the time, were destroyed. Most of Royal Gardens, however, was spared. In 1986, when the eruption shifted to Kupaianaha, the new flows were kept to the east of the subdivision by the ‘a‘ā flows emplaced earlier. It was only on the coastal plain, where the Kupaianaha flows could move unhindered to the west, that a significant portion of Royal Gardens was buried and several more homes destroyed.

When the eruption returned to Pu‘u ‘Ō‘ō in 1992, lava flows stayed almost entirely in Hawai‘i Volcanoes National Park, and it was a decade before lava reached Royal Gardens again. In 2002, a narrow finger of lava crept back into the upper part of the subdivision, and a few years later, other flows completed the burial of that portion of Royal Gardens on the coastal plain.

But for years—from the late 1980s through the mid-2000s—the Royal Gardens subdivision stood out as a green oasis perched on the steep slopes of the Pūlama pali, a shallow valley flanked by higher-standing expanses of black lava. Largely abandoned by that time, its location made it marked territory, and when the episode 58 vent opened between Pu‘u ‘Ō‘ō and Kupaianaha in 2007, the lava flows were bound by gravity to follow the valley like water in a streambed.

The next four years of eruptive activity, from 2007 to early 2011, nearly erased Royal Gardens, destroying most of the structures that were still standing, leaving only a few scraps of forest near the base of the pali surrounded by the episode 58 flows. The largest surviving patches of Royal Gardens on the pali remained along the western edge of the subdivision, adjacent to the boundary of Hawai‘i Volcanoes National Park. It was in the lower portion of these western kipuka where the last occupied house stood—until early March 2012.

The Peace Day flow, originating from Pu‘u ‘Ō‘ō's eastern flank in September 2011, initiated the most recent round of destruction. Once again confined to the "valley" between adjacent flow fields, the Peace Day lava flows have been repeatedly funneled downslope through the remaining kipuka. Less than 5 percent of the subdivision now remains.

Small portions of the Royal Gardens subdivision will almost certainly survive this latest round of surface flows, and some areas may even survive this seemingly endless eruption. But while watching lava flows pick at the subdivision’s bones, one cannot help but notice that Kīlauea's efforts to bury Royal Gardens are nearly complete.


Volcano Activity Update

A lava lake present within the Halema‘uma‘u Overlook vent during the past week resulted in night-time glow that was visible from the Jaggar Museum overlook. The lake, which is normally about 90–115 m (295–377 ft) below the floor of Halema‘uma‘u Crater and visible by HVO's Webcam, rose and fell slightly during the week in response to a series of large deflation-inflation cycles.

On Kīlauea's east rift zone, surface lava flows were active on the pali and upper coastal plain, in Royal Gardens subdivision, over the past week. As of Thursday, March 15, the flows were still about 2.7 km (about 1.7 miles) from the coast, and there was no active ocean entry.

Two earthquakes beneath Hawai‘i Island were reported felt this past week, both on Tuesday morning, March 13, 2012, but on different islands. A magnitude-3.3 earthquake occurred at 10:27 a.m., HST, and was located 6 km (4 mi) southeast of Lāna‘i City, Lāna‘i, at a depth of 1 km (0.4 mi). A magnitude-3.4 earthquake occurred at 11:39 a.m., and was located 6 km (4 mi) south of Volcano Village at a depth of 2 km (1 mi).