Mauna Loa

Mauna Kea

Collapsed lava tube

Near the summit crater

Why I chose Mauna Loa (4,169m) rather than Mauna Kea (the highest mountain in Hawaii) for my climb is simple. Mauna Kea is 37m higher, but there is a road all the way to the top, and in addition to a car park, the summit sports a number of huge and world-leading astronomical observatories. By comparison, the summit of Mauna Loa is pristine. There are a few small instruments set up to observe the caldera, which is regarded as very active, although it has not erupted since 1984. It is overdue, as it normally erupts every six years. Though not the highest volcano on earth, Mauna Loa is considered the second largest. Like all the other volcanoes on Hawaii, it is a shield volcano, ie its profile is like that of a shield, very flat compared to cone-shaped volcanoes such as Mt Fuji.

Today was my "Boy's Own" for this trip. I wanted to add another 4,000m mountain to my collection, to bring the grand total up to 16. Lonely Planet writes, "Drive to the Mauna Loa Observatory at 3,399m then pick up the 10.3 km walking trail for the remaining 770 m to the top. It's a steep, exhausting all-day adventure, but also an exceptional one that allows experienced hikers to conquer a 4,000 m mountain in one day." They advise you to begin hiking before 8 am, but I thought this too conservative, so I aimed for an 8.45 start, as it is a two-hour drive from Kailua. They warn that it is cold the year-round, which seems correct.

I got up at 6.30 and reached the observatory at 8.30. The last 31 km were on a one-lane road through the lava fields, so this was slow. I had to check for oncoming traffic around every bend and over every dip. I saw three wild goats at the start and then the landscape became desolate, with the road climbing consistently but deceptively. Luckily there was no traffic at all. After an hour on the narrow road I parked my car at the metereological observatory. There were no other cars and no people to be seen. There was a good view of the astronomical observatories on nearby Mauna Kea rising above the clouds.


The crater

I followed the sign pointing to the start of the summit track, which is marked by cairns. I had a slight headache and found the climb tiring because of the altitude. Obviously, I wasn't acclimatised. The only living creatures I saw all day were three spiders, two flies and three bipeds. There is not a blade of grass on the mountain above the observatory. Presently, I reached a four-wheel-drive road, which consisted of aa lava gravel. The track followed the road for a while and then I arrived at a viewpoint over the caldera, which was far below. Here there is a track going left towards a cabin and another headed for the summit. The caldera is vast - probably some six km in diameter. Its surface is flat, looking like molten lead that has solidified. Near the caldera there were some small lava tubes that had collapsed, as well as lava of different colours. Very light and brittle pieces of black spongy-looking lava glistened silver, gold, copper and even blue. The dominant colours on the ground were still black and brown, but there were some orange stones. Here I met two girls who were returning from the summit.

It seemed like I was near the summit, but the trail obstinately wound upwards more or less following the edge of the caldera. Though only about 3 km long, it seemed to go on forever. Occasionally, it was hard to discern the next cairn, or else there were too many of them, so that it was hard to know where the trail actually lay. I didn't worry about following the track exactly as it was quite indistinct and generally only a little easier to walk on than the surrounding lava, which is predominantly pahoehoe. This is easy to walk on.

Six hours after setting out I reached the summit at 2.45. It is marked by a cairn and a guest-book in a metal case. I signed my name but could not think of anything interesting to write. The view over the caldera was similar to the initial one, though somewhat more expansive. I was very tired and the entire climb had been a continuous big effort. It had not been a pleasure at all, though I realised I would probably forget this next time I got the idea to go up a hill. The track is through weathered pahoehoe lava for about 95% of the way, with occasional patches of aa lava. Pahoehoe is the smooth lava that takes on a ropey appearance when it meets an obstacle. Aa lava is broken up and consists of very rough stones about the size of grapefruits. The pahoehoe lava has a checkerboard appearance due to weathering of its surface. It made me think of snakes made of stone that were breaking up. Pahoehoe is formed at a higher temperature, hence it flows more smoothly.

Pahoehoe lava

Mauna Kea

I followed the markers back the way I had come, but after a while I had the not-so-bright idea of taking a short-cut, rather than going all the way back to the fork. Looking for a descent at an earlier point, I spotted the four-wheel-drive road and headed for that. I hoped to find the point where the track met the road, but I was probably below that point by the time I hit the road. I was anxious to get down quickly, as I knew that Carla would be worried about me if I came later than promised, which was 9 pm. I followed the road for a while, but it did not seem to be descending and I didn't know whether it went to the observatory or not (which it probably did). It wasn't pleasant to walk on either. I decided to descend more or less straight down the mountain, angling a little across to meet the observatory, which was not visible. However, I had the Mauna Kea summit as a direction indicator.

The descent proved very difficult, as there was a lot of aa lava, which is unpleasant to walk on. Right at the beginning I tripped and fell forwards. Since I broke my fall with my hands I cut my hands on the jagged aa lava and sprained a finger. After that I exercised more care and did not fall again. I looked for pahoehoe flows, as these are much easier to navigate. Unfortunately, the aa lava predominated, and this explains why the track itself is indirect. It was rough going and I gave thanks for my sturdy Scarpa boots. Had I worn sneakers these would have disintegrated on the descent. It was tough going, but I acquired proficiency at walking on the aa rubble, which is just loose rock, ie unstable. Presently, the astronomical observatory came into view below me and I took heart, as it did not seem far away, and it was in the direction I was following. However, after descending a half kilometre the observatory did not seem any closer, so I realised I still had a fair way to go. It was probably another two kilometres, mostly through aa and the observatory began to grow in size. However, it was getting dark as I reached the car at 6.50, a few minutes before sunset.

There were no cars or people around and I set off down the one-lane asphalt road as it began to drizzle and get dark. At least I knew that I would see the lights of any oncoming vehicle. Sometimes though, I forgot it was a one-lane road and drove too fast. Luckily, there was no-one but me until the highway. I got home before 9 pm, as promised, despite my "short-cut", which had been a much longer descent than following the path. Some people never learn.

Tad Boniecki
October 2016

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