Earth's Biggest Mountain, Part 1
Ascent of Mauna Loa via the Observatory Trail
Wednesday, February 29
Drying and prepping
By 9:30 am, we were ready for our two-day journey up Mauna Loa. We had dried out our wet gear and packed fairly lightly given our short itinerary and accommodations. Although we were planning to stay overnight in the cabin near the caldera rim, we had still packed a single tent for any emergency situation that might force us to camp out in the open.
Starting, Observatory Trail
The Observatory Trail starts out along a jeep trail that continues switchbacking up the slopes of Mauna Loa. It followed this old road for less than half a mile, then made a sharp left and headed straight up the slope in the general direction of the summit. We were now hiking on an old pahoehoe lava flow - in other words, on solid bedrock - and there was little to no discernable tread to follow. As a result, the Observatory Trail was generously marked with cairns - or, as you would say in Hawaiian - ahi.
The grade was moderate - but never really that steep. Mauna Loa, like all of the Hawaiian volcanoes, is a shield volcano. The slopes of shield volcanoes are very broad and shallow - owing to the fact that the basaltic lava that flows from these volcanoes is quite fluid compared to other types of lava. As a result, it does not form very steep slopes.
Remnants of recent snowfall
I was somewhat glad of the fact that the slope wasn't that steep, for this helped compensate for the fact that we had started hiking at quite a high altitude - 11,000 feet - and were steadily climbing higher. We were well within the zone where altitude effects are felt, and even though we had had some acclimitization on Haleakala's 10,000-foot peak a few days prior, we were feeling the extra effort required to climb in the very thin air.
Given the altitude, we kept it down to a nice, slow pace. The conditions around us were quite tranquil: there was hardly a breath of wind, and there was a decent amount of warmth from the sun, although it had to shine through a high overcast. Scenically-speaking, though, the high overcast dulled our view of the landscape around us.
Across the saddle to Mauna Kea
The trail eventually crossed the zig-zagging jeep road a couple of times, then reached a small sign marking our crossing into the lands of Hawai'i Volcanoes National Park.
Crossing national park boundary
The snow, which had been an occasional patch off in the distance down at the trailhead, was becoming much more prevalant up here (we had at this point climbed over the 12,500-foot elevation mark). We had come to a section of the trail that has a discernable tread through an area of fine lava sand, and hence a reduced need for cairns, but the large amounts of snow which now covered things made it in places hard to discern where the trail went. Fortunately, the occasional bare patch along with the faint tracks of a previous hiker helped point the way.
Although snow can often be an aid to hiking and climbing, by providing a smooth surface over top of irregularities, it can be an annoyance when it is too soft to support your weight. Such was the case today: it had a consistency that allowed too much sinkage to be comfortable, and we took some care to avoid the snow patches, when possible. Even having snowshoes (which normally make soft snow a non-issue, and which we did not have in any case) would not have worked, for there were too many bare patches of sand and bedrock to make them practical.
Down to northeast rift zone
Three hours after starting out from the Observatory Trailhead, we reached a significant point along the route - the junction with the Mauna Loa Trail, and the edge of The North Pit - a low point along Mauna Loa's large summit region. From here, three different trail routes branched out: the lower Mauna Loa trail, leading down to a different trailhead; the summit trail, which we would be soon taking; and the upper Mauna Loa trail, leading to the Mauna Loa cabin on the caldera rim. After reaching the summit, we would be retracing our steps to this point and continuing on to the cabin for the night.
The North Pit
We had reached approximately to the 13,000-foot level at this point - over 4,000 meters - a pretty high elevation by most standards. In addition to feeling generally more easily winded, we all started to experience some mild altitude sickness in the form of mild headaches. Back at the last grocery store, we had purchased some aspirin (a basic tool one can use for mild AMS), and we each popped a couple at this point. And, also attempted to continue to hydrate ourselves well - another way to help reduce the effects of altitude sickness.
Looking out over the North Pit and to the larger main summit caldera beyond was a humbling experience: it was a vast, desolate place - less like the summit of a mountain and more like a cold desert on the moon of some outer planet. This feeling of desolation was amplified by the patches of snow and thin, wan sunlight coming through the high overcast. Perhaps just like the feeling of the more distant sun one would experience on such a moon.
A bit of fancy trailwork
Due to our slow pace, time was slipping by a bit faster than we wanted, so we tried to increase the pace a bit as we started off on the 2.5 mile-long summit trail. The grade was quite gradual now - we only had about 700 feet more to gain to the actual summit, but the overall roughness of the trail in many places slowed us down. We were discovering that almost all of the trails high on Mauna Loa are on solid rock - and solid rock does not easily yeild a soft tread with the passing of many hiker's boots. It stays quite solid - unevenness and all.
Seismic Monitoring Equipment
With the day's efforts slowly wearing us down, we eventually approached the summit, passing a few seismic monitoring instruments along the way. The trail soon reached the caldera rim, and we were presented with a sweeping view, 700 feet below us, of it - all eight square kilometres of it. That's a damn big space to comprise just the caldera at the top of a volcano!
Due to a poorly-worded waypoint within my GPS, we thought that this point we were at along the caldera rim was the highpoint. However, a quick glance along the rim seemed to indicate that there a higher point further along. Some consultation with our paper topo map unhappily revealed the fact that our hunch was true - we were not at the true summit. I say "unhappily" because we were getting a bit bagged, and the time left before sunset was growing short, and we had a fair bit of walking to do before getting to the refuge of the Mauna Loa cabin. You see, the cabin was directly across the caldera, at a point on the rim opposite to where we were now. And, there was no way to get from here to there except via the long circuitous 8km walk around (Going the direct route - down a treacherous, crumbly 700-foot vertical cliff - was obviously not an option).
However, we weren't about to leave after coming 99% of the way to the top, so we pushed on, covering the remaining few hundred yards in about 15 minutes. A large cairn strewn with various knicknacks - among others, a bit of sea shell, a length of rope, a bandanna, a stretch of Tibetan prayer flag - marked the high point.
Brian and Andrew on top of Mauna Loa
Jenn, summit of Mauna Loa
After taking some requisite summit photos (this, by the way, was Jennifer's new altitude highpoint record), we promptly started on the journey back to the junction near the North Pit. It was a quarter to four, and we had two-and-a-half hours until sunset; and another 30 minutes of usable twilight after that. Three hours to make our way to the cabin before dark.