With the recent downgrade of the volcano alert level for Kilauea’s June 27 lava flow that has been threatening the Pahoa area, it’s interesting to take a look back at the 1880-81 Mauna Loa lava flow and the threat that
With the recent downgrade of the volcano alert level for Kilauea’s June 27 lava flow that has been threatening the Pahoa area, it’s interesting to take a look back at the 1880-81 Mauna Loa lava flow and the threat that it posed to Hilo.
On the evening of Nov. 5, 1880, people in Hilo and at the Volcano House Hotel at the summit of Kilauea noticed a glow on Mauna Loa — produced by an eruption located northeast of the volcano’s summit. A vent at about the 3,200 m (10,500 ft) elevation produced one lava flow that moved to the southeast and stalled about 2.5 km (1.5 mi) from Highway 11 near Kilauea caldera. A second vent, immediately downslope of the first, erupted a pahoehoe lava flow that advanced to the northeast toward Hilo.
By January 1881, the northeast flow was estimated to be about 30 km (18 mi) from Hilo. This flow was of interest to Hilo residents, but not a big concern. However, by April the flow had split into three branches in the vicinity of what is now Kaumana City, a subdivision at the upper Hilo city limits, and advanced to within 11 km (7 mi) of the town.
By the beginning of July, a single branch was only 4 km (2.5 mi) from Hilo.
The flows initially were difficult to access. But by July, the flows had moved close enough to Hilo that residents and visitors alike frequently were trekking up to the flow to watch its progress. They observed that the pahoehoe would advance very quickly as narrow fingers for short periods of time and then stall, only to repeat the process a few hours or days later. Astonishing stories of narrow lobes of lava advancing hundreds of feet in a few hours were common.
Observers occasionally would note the lava sometimes occupied a ravine or gulch where water flowed during heavy rains. As the flows got closer to Hilo, people often noticed that warm water seemed to flow out from under the active lava.
As the eruption continued, Hilo residents became alarmed, and many started moving their belongings out of harm’s way. The branch closest to Hilo split into two lobes, with one headed down ‘Alenaio gulch toward the center of Hilo and the other headed down Kalanakama‘a gulch (near and parallel to Mohouli Street) toward the Waiakea Fishponds and Sugar Mill (Wailoa State Park).
Everyone feared the lava would cut through town and enter Hilo Bay.
Just as concern was getting intense, the leading tips of both lobes stalled on or about Aug. 10, with the Kalanakama‘a lobe a little more than 1.6 km (1 mi) from Hilo Bay. The ‘Alenaio lobe didn’t quite reach Komohana Street. The lava destroyed only one house near the current location of Kaumana Elementary School. By Aug. 19, the lower portions of the flow were inactive.
This Mauna Loa flow differed from Kilauea’s June 27 flow in two significant ways.
The Mauna Loa 1880–81 flow is about twice the length of the June 27 flow, and the Mauna Loa eruption rate probably was higher.
But there also were some similarities.
The Mauna Loa 1880–81 and the Kilauea June 27 lava flows were both pahoehoe and active for about nine months before their threats were reduced. Both flows greatly concerned the people who lived and worked downslope of the advancing fronts, but the flows consumed only a single house before their leading edges stalled.
And both flows cut a swath through heavily forested land.
But in the case of the 1880–81 Mauna Loa flow, the open swath it cut through the forest eventually improved travel from Hilo to Waimea and Kona via the saddle between Mauna Loa and Mauna Kea. Years later, Saddle Road, as it is now known, took advantage of this path. Today, Saddle Road crosses four Mauna Loa flows — the 1880–81, 1855–56, 1899, and 1935 flows — between mile markers 3 and 29.
While the 1880–81 Mauna Loa eruption might have had a beneficial aspect — blazing a trail for Saddle Road — that’s not always the case with active lava flows.
Kilauea activity update
Kilauea’s East Rift Zone lava flow continues to feed three areas of breakouts near Pu‘u ‘O‘o. The breakout 6 km (4 mi) northeast of Pu‘u ‘O‘o was the farthest downslope activity observed March 24. The lava flow near Pahoa is no longer active.
There have been no major changes at Kilauea’s summit vent, which continues to host an active lava lake. The lava lake level continues to fluctuate, with the level rising during the past week. The lava level was 37 m (120 ft) below the rim of the Overlook crater on March 26.
There were no earthquakes reported felt on the the Big Island during the past week.
Visit the HVO website (http://hvo.wr.usgs.gov) for past Volcano Watch articles, Kilauea daily eruption updates and other volcano status reports, current volcano photos, recent earthquakes and more; call (808) 967-8862 for a Kilauea summary update; email questions to askHVO@usgs.gov.
Volcano Watch (http://hvo.wr.usgs.gov/volcanowatch/) is a weekly article and activity update written by scientists at the U.S. Geological Survey`s Hawaiian Volcano Observatory.
