There are few open paths to trail ride on this island, a place where landowners gate every side road and jealously guard any access. There are a number of exceptions, but you have to look to find them. One such is a power line road off of Saddle Road. The power line is gone now, the stumps of poles remain where they were sawn down years ago. The road runs arrow straight across the landscape, now serving forestry crews, pig hunters and hikers. Enough traffic traverses the path the keep it clear of growth. Here is a glimpse of natural Hawai’i, where invasive species are relatively few and the calls of native birds echo amongst the ‘Ōhi’a.
Getting ready to set down the trail to Emesine CaveWhile I had hiked the trail a couple years past, cycling gave me a whole new appreciation for the ruggedness of this old power line road. Whole sections were cobble that shifted and rolled under the knobby tires. I got a lot of rock dodging practice, carefully choosing where to run my tires through the rough lava. In the end I was forced to walk the bike along whole lengths of the route where the loose cobble was simply too dangerous to ride. The sections among more recent flows were the rough parts where the road was simply bulldozed through the rock.
It may be a rough trail, but the goal is worth it, a relatively recent cave with an array of classic lava tube features. Emesine cave, is found in the 1881 lava flow that threatened to flow into downtown Hilo, but stopped just short of the city. Today, over a century later, the cave is now an excellent example of volcanic action and how life returns to reclaim the land afterwords.
The entry of Emesine CaveErupting from a vent high on the eastern rift zone of Mauna Loa, this flow was typical of Mauna Loa flows. There had been a small summit eruption several months earlier, then a series of lava fountains that fed ‘a’ā flows down either flank of the eastern rift zone. The most dangerous phase of the eruption began mid-November 1880, when a fissure opened lower on the mountain that fed a series of lava tubes. Pahoehoe lava traveling down-slope in these well insulated tubes allowed the flows to advance further and faster than the earlier ‘a’ā flows.
The flows did not stop until August 10th 1881, reaching within a few miles of downtown Hilo. Some fingers of the flow crossed the present day Komohana and Kumukoa Streets near the University of Hawai’i at Hilo campus. When the flows finally did stop a number of lava tubes were exposed, including Kaumana caves, a popular tourist attraction above Hilo. Also formed in the eruption was a series of tubes higher on the north flank of the volcano, Emesine cave.
I was determined to get out and use the telescope during the March new Moon, but had planned to go observing with the guys at Hale Pohaku on Mauna Kea. At the last minute I decided to accept an invitation from the Hilo group to observe from Mauna Loa instead. The guys planned on running a Messier Marathon, something I have enjoyed many times before.
Our usual observing location is Hale Pohaku, at 9,000ft on the south side of Mauna Kea. Hale Pohaku is a great observing site, high enough to be above the clouds, but well below the summit where thin air, wind and frigid temperatures can be miserable. It is impossible to do a complete Messier Marathon from Hale Pohaku, the bulk of Mauna Kea blocks too much of the northern sky making a few objects, most notably M52, difficult to impossible.
The Mauna Loa access road, carved through the lava and paved with red cinder asphaltThe road and climate research station on Mauna Loa sit on the northern face of the mountain, offering a perfect vantage point for the Messier catalog objects given our 20° latutude. The only issue is the road. While Hale Pohaku is reached by six miles of quite nice state highway, Mauna Loa requires navigating an 18 mile drive up a single land paved road. Use of the word “paved” is somewhat casual, as is the maintenance on the road. The first few miles feature new pavement. Beyond that? Not so much, the road becomes a pothole obstacle course. Driving the road with a delicate telescope in the back is rather nerve-wracking.
Vintage film of Mauna Loa eruption during 1940 by Harold T. Stearns, a USGS Hydrologist-Volcanologist.
An eruption of Mauna Loa is something everyone fears and hopes for. This enormous volcano will erupt again, almost certainly within our lifetimes, possibly even the next decade. The last eruption was in 1984, the mountain has been quiet for well over two decades now, an uncharacteristically long period of quiescence. When it does erupt this volcano is capable of emitting huge volumes of lava, that reach the sea quite quickly down the steep slopes A dangerous mountain to be wary of.
