Spelunking Emesine Cave, Part 1

About two weeks ago on Good Friday I organized an excursion with some friends to explore Emesine Cave, a lava tube high on the flank of Mauna Loa created in the 1880-1881 eruption that came perilously close to destroying Hilo. It exists as several disconnected sections totaling over ten miles in length, making it the fourth-longest lava tube in the world as of right now.  However, the section we explored at about 2,300 meters (5,700 feet) elevation was only about a mile in length.

I took quite a few pictures this trip, so much so in fact that after looking through them I've decided to split this post into multiple parts.

Unlike the Kaumana Caves county park where the entrance is just a few dozen feet from the parking lot, the entrance to Emesine Cave is found only after a 2.6 mile hike at nearly 6,000 feet. For being so high, the lower air pressure didn't really bother anyone as I was afraid it might. WolframAlpha suggests the pressure would be about 812 millibars, which is close to 80% of sea-level pressure, so I guess it wasn't really that bad. Hindsight, and all that.

The hike was pleasant, following the remains of a straight road that remained mostly flat or only slightly inclined along its length. We passed through several stands of older forest among the more barren and recent lava plains. Hawaiian has a word for these islands of older forest surrounded by newer flows of lava: kīpuka. These particular kīpuka are great habitats for some of the endemic Hawaiian birds, and it was really lovely to get out of the constant background noise of Hilo and hear some actual birdsong again. We didn't see many birds, but the sound of their song was a constant background for us along our trek.

Here's a panorama I took with my phone. I think it does a good job of capturing the feeling of the vast lava plains we were traversing.

Unfortunately you can't really see much in it, other than the dark surface of the lava in the shadow of all those fluffy clouds. If you click on it to blow it up, you can see the base of Mauna Kea off to the left.

Along the way I had some of these pointed out to me. They're called ʻŌhelo berries, or Vaccinium reticulatum. They're actually edible (and related to cranberries), so I ate a few. They grow wild at altitudes between 640–3,700 m (2,100–12,100 ft) in the rich volcanic soil, and are a popular ingredient in home-made jams and jellies in Hawai‘i, in the same way wild raspberries or blackberries might be on the mainland. The ones I consumed mostly didn't have much taste, but some of them were moderately sweet. The color doesn't necessarily indicate ripeness, I later learned.

When we finally got to the entrance, we found a large skylight perhaps thirty to forty feet across and about twenty feet deep that provided entrance to the tube. Unlike Kaumana Caves, there were no easy-access steps-with-accompanying-handrail going down into this one, so we had to clamber down the jumble of collapsed rock inside that fortunately came up close enough to the edge on one side to permit entry.

Entrance to Emesine Cave.

Since the guidebook I'd read said that the uphill side of this section was fairly uninteresting, we headed downhill.

There are a lot of interesting features in Emesine Cave. It's also an easier walk nearly its entire length than much of Kaumana Caves, which was nice. Most of the floor is easily-traversable cauliflower ʻaʻā, with little of the collapsed rock from the roof that makes Kaumana Caves so difficult to explore in places. Emesine Cave also tends to have a flatter grade than Kaumana; up this high on the flank of Mauna Loa the lava was flowing nearly horizontally and traveled for great distances in fairly uniform conditions without losing much heat. Contrast that with Kaumana Caves, near the end of the flow, where the terrain was rougher and the flow more intermittent, producing a huge diversity of features that change rapidly on short distance scales.

Anyway, enough talk, you want pictures!

One thing that never gets old in lava tubes is the amazing variety of colors. This photo was taken near the entrance, so I think the green is some kind of photosynthesizing-life, but it might also be olivine. And the white may be gypsum that crystallized out as the lava cooled.

This is a ledge extending out from the wall, showing where a tube-in-tube formation might have formed if the lava level had held steady.

Close-up of the previous picture. The saw-tooth structure is amazing, I've never seen anything like it before in a lava tube. Reminds me of a fish fin.

I love the whorls and contrast in this picture. It just doesn't look like solid rock, does it?

There are some massive formations of these kinds of lava-cicles in Emesine Cave. Near the top of the picture just left of center you can see some that appear to come in ridges, which may have something to do with how air was flowing through the tube when they formed.

As you approach the first (and only) skylight in Emesine cave, the tube splits just before the opening, giving you two exits. This is the right one, which is traversable (I tried it coming back), but not comfortably (I had to hunker down and waddle through for about twenty feet).

The left side is easily walked at full height, even for me. (Ignore the roots in the foreground, they're hard to see in the dim light of your flashlight and it isn't until you get home and look at your pictures that you realize just how much light they reflect and how badly they interfere with your photos.)

Anyway, I think I'll end it here for now. Look out for the next part to come soon!