Farewell gifts (and geese)

In addition to the larger furniture pieces I showed off in my previous post, I've been making a number of smaller woodworking projects too. Two friends of mine are both moving away from Hawaii in the near future, so I put my newfound skills to the test to make them some farewell gifts.

For my friend Mark, I wanted to try an end-grain cutting board after watching a video on how to make them. Basically, you glue a bunch of strips of wood together (all cut along the grain, or “rip cut”), then cut them in strips across the grain (“cross cut”) and flip them up 90° so that the end face of the board is made up of the end grain faces of each piece (the end grain is where you can see the rings). I haven't been able to test it myself yet (for reasons of time), but from what I've heard this results in a more durable cutting board than simply leaving those strip glued together to make an edge grain cutting board, though it's also more work (and has more wood lost to kerf from making more cuts). Experienced woodworkers can make all kinds of fascinating patterns by the selection, arrangement, and cutting angles of various kinds of wood, but the basic premise is relatively simple.

After wetting it down to “raise the [wood] grain” to get a smoother sanded finish.

The project still took me over a week, since I discovered the miter gauge on my table saw isn't really accurate enough for repeated cross cuts like I needed to make. I ended up with a bunch of wood strips which, when glued together, weren't all quite the same thickness. There are some tools which could potentially solve this easily, but I don't have them, so I had to spend hours trying to sand down and smooth out the irregularities. (Going forward I intend to preemptively solve this by making a cross cut sled, a simple jig made using plywood and some screws which should make getting repeatable cross cuts much easier.)

And here it is after applying a protective mineral oil and wax finish.

Anyway, after a lot of sanding and small cosmetic fixes I got it to a state where I'm mostly happy with it. It should serve as a cutting board, at least, even if it's not perfect. I wanted to make something using local woods as a reminder of Hawaiʻi, so I used koa and ʻōhiʻa (plus some African padauk for a pop of orange contrast. The edges and center are koa, with ʻōhiʻa to either side of it down the middle and then padauk just inside the edges.) I haven't decided on whether it'd be better with things like a juice groove or edge handles, but since Mark's still got some time before he leaves I'll probably just ask him.

For my friend Josh, whom I worked with at my job with NEON last year, I decided to make a little coaster from some scraps of Phillipine mahagony I had from another project (which I'll reveal at some point). A few years ago I bought some novelty coasters designed to look like little wooden pallets, and I thought something like that would make a practical gift.

Raw materials after cutting them out, and the inspiration.

The strips of wood I had were slightly wider than in the original coasters, so I went for a solid flat face on the top. The result came out looking pretty good, in my opinion!

And since Josh enjoyed seeing the nēnē while we were working up in the natural area reserve, I pulled out my wood burning kit and doodled a quizzical nēnē from a photo I took while visiting the Hakalau Forest National Wildlife Refuge last year. This project was a lot quicker, and only took me a few hours over the course of a day.

The inspiration…

…and the (slightly off-center) result.

While the occasion of their creation is for less-than-happy reasons, it was a lot of fun to stretch my creative muscles for these projects and make something new. I like making practical furniture, but it's also nice to make smaller practical (and decorative) wood pieces. I've got more things to show off here at some point too, so stay tuned! A hui hou!

Visiting Volcano National Park: Part II

Last post I introduced my trip to Volcanoes National Park last week. The first part was a bit short because I felt a single post would be too long, and the Kīlauea Iki hike really ought to get a post to itself.

Kīlauea Iki is the name of a pit crater that developed to the east of the main Kīlauea caldera in 1959, catching vulcanologists of the time by surprise and forming a lava lake measuring 0.7 by 0.4 miles. You can see it below as it looks from the trail head up on the top of the surrounding cliffs:

Kīlauea Iki, seen from the top of the cliffs around it.

The large bare hill in the center of the picture was created during the 1959 eruption from some spectacularly high lava fountains (up to 1,900 feet! [580 m]) and is known as Puʻu Puaʻi, which translates to something like “gushing hill.”

The trail makes a loop around the north rim of the pit, then dives swiftly down to the floor of the frozen magma sea and cuts across it back to the base of the cliffs below where the trailhead is, before steeply ascending to come out near another famous park sight, the Thurston Lava Tube (alternatively you can walk the trail in reverse order, that's just the way we went).

Here you can see the floor of Kīlauea Iki. The gray streak from left to right is the path.

Cores drilled in the lava field show that the entire lake solidified within a few tens of years after the eruption, but the rock is still quite hot. Putting my hand on it at one point I was surprised to feel that it was markedly hotter than would be expected from solar heating based on the weak sunlight coming through the cloudy, overcast sky. In a few places steam could be seen continually wafting off the surface, similar to the Steam Vents I showed last post.

Eventually we wound our way around the crater rim till the trail began to switchback steeply down the inside of the bowl, until we got to the bottom where this sight met our eyes:

Panorama of Kīlauea Iki. Ignore the horribly overexposed sky. Mouseover for original handmade panorama!

From the floor of the crater, a landscape more reminiscient of Mordor could hardly be imagined. For some reason this immediately suggested the following picture to me:

I mua! Forward!

After this, we set out across the great arid plain, following the trail to the base of Puʻu Puaʻi. Although the vast expanse of rock showed no signs of life from the crater rim (other than the many tourists wandering along its trail), we soon found various plants, shrubs, and even young trees sprouting up in places through the rock, clinging to life in an inhospitable environment. One such example is the ʻōhelo berry bush below:

ʻŌhelo berries growing in Kīlauea Iki crater.

ʻŌhelo (Vaccinium reticulata) are endemic to the Hawaiian isles and are adapted to grow on volcanic soil high up on the flanks of Hawaiian volcanoes. They're an important source of food for the state bird, the nēnē, and being relatives of cranberries and blueberries they are also human edible. ʻŌhelo berry jam from wild-picked berries is a popular home-canning project.

Near the base of Puʻu Puaʻi I found a large crack in the ground about as deep as I was tall, and tried to pose for a picture of me desperately hanging onto the edge. The lava turned out to be a lot sharper on bare skin than I had anticipated, however.

I did, however, manage to get the picture below:

Hang in there!

After these shenanigans at the foot of Puʻu Puaʻi, we set out on the trek across the main portion of the crater floor towards the far side and the trail leading back up to where we started. It was a fascinating experience, walking over the crystallized undulations of the solidified lava lake, its final random motions frozen in stone and time. Most extruded lava in Hawaiʻi is bumpy and rough to some extent, so it was very strange seeing (and walking on) such smooth rock. In places it had been broken up, victim to the stresses and strains of thermal expansion and contraction as parts of the lake cooled down unevenly. A little ways out from the base of Puʻu Puaʻi I looked back and got this picture:

At a few places on the crater floor steam was rising from the ground in a continuous display, reinforcing the Mordor look. You can see one such place in the picture below:

I investigated one to see if the steam was coming from a crack or other aperture, but it simply seemed to be rising straight out of the ground.

From across the floor of the crater we took one last look back at Puʻu Puaʻi across the frozen lava sea before turning and beginning the torturous ascent back to the crater rim.

I would have to say that this hike across Kīlauea Iki was the high point of the trip for me. There's just something incredibly cool about walking across the surface of what was a roiling, boiling lake of molten lava a little less than four score years ago. If you ever visit Volcanoes National Park, have the time, and are prepared for a hike of several miles, I would definitely recommend going on this one. Especially if you read some of the helpful information boards at the head of the trail first.

As a final photo, have this picture of an ʻōhiʻa lehua blossom that I took at the side of the trail along the rim of the crater. They're quite spectacular up close.

Anyway, that's been part two of my photo series. Tune in next time for the last part of our trip, and to see what happens when lava runs over a modern asphalt road! A hui hou!

Kaumana Cave Crawling

Located a little ways beyond the outskirts of Hilo just off Kaumana Drive is Kaumana Caves County Park. The eponymous caves are actually the remains of a lave tube formed during the 1881 eruption of Mauna Loa that came within a few miles of wiping out Hilo. Lava tubes come about during an eruption when the surface of the flow cools and forms a crust beneath which lava continues to flow, eventually concentrating into channels that may eventually empty of lava and become hollow. Sometimes the roofs of these channels collapse in “breakdowns” (making “entrances” or “skylights”), places that you can potentially climb down and enter the tube. The Kaumana Caves County Park contains one such entrance at an elevation of about 1,000 feet with a handy flight of steps leading down to the lava tube floor. (There's a neat site here with some good pictures that explains many of the terms used in lava tubes.)

Anyway, the point of this post is that last Sunday I had the chance to explore the caves for myself for the first time, along with a co-worker who had never been before either. Upon descending the steps into the skylight in the park, we were immediately faced with a choice: left or right (since the skylight is in the middle of the tube, it continues both uphill and downhill on either side).

Entrance to the right side of the Kaumana Caves lava tube.

We chose to investigate the left-hand (uphill, or mauka) side, because I'd heard that it was a bit shorter than the right-hand side. So, not the side that I actually took a photo of. The entrance to the left side looks similar except that it appears to end in collapse a short way in. It doesn't, but it may not be immediately obvious.

Warning sign at the bottom of the steps.

While this isn't exactly what I would term a dangerous cave in the sense that you don't have to worry about slipping and falling dozens of feet onto stalagmites at the bottom of a pit, it is very definitely a cave left very much in its natural state. Unlike the more famous Thurston lava tube near Kīlauea which has a smooth floor and electric lights installed, the Kaumana lava tube has a much rougher floor in places due to collapse of the roof and has no artificial lights of any kind.

Surprisingly, I wasn't able to find much information about the cave online, other than that it was formed by the 1880 eruption of Mauna Loa which everyone agreed on. Various sites listed distance up to 22 miles long if it weren't for roof-collapses that blocked the tunnel; however, a site I found listing the world's longest lava tubes ranked the Kaumana lava tube at #63, at 1.365 miles in length.

(Interestingly, the top four longest lava tubes in the world are all on Hawai‘i island, and are all over 10 miles long. Emesine Cave, the fourth-longest at 12.89 miles, was also formed by the same 1880 eruption of Mauna Loa as Kaumana Caves, and is located further up the flank of the volcano. The longest one, called Kazumura Cave, is located about 20 miles south of Hilo, was formed about 500 years ago by an eruption from Kīlauea, and contains a whopping 40.7 miles of total length!)

Anyway, getting into the left entrance of the Kaumana Caves involves finding it first. It's not that hard to spot, but the lava tube mouth is somewhat obstructed by the roof collapse that formed the entrance that permits entering it in the first place, and it's not immediately obvious to the casual glance. Once inside, the view is spectacular. I'm finding myself at a loss for words to describe what it looks like. The rocks on the inside are so unlike anything I'd ever seen before that I had to keep telling myself that no, they weren't fake movie props from some Hollywood set. It's an excellent case of real life being stranger than someone could ever think up.

Once inside, I found myself surrounded by a fantastic menagerie of strange and fluid shapes. All about me were the cooled remains of once-molten, living rock now frozen into a bewildering variety of poses. The bizarre, colors, lumpy shapes, and uncharacteristically smooth surfaces were so far removed from my everyday perception of what rock is that my mind had a hard time recognizing the mysterious substance around me as mere stone. Light-reflecting minerals coated the walls and ceiling, throwing the light of my small headlamp back from a myriad facets like a multitude of tiny stars. Everywhere the colors red, black, and silver met my eye. It really was a surreal experience, a place unlike anywhere else I've ever been. They say a picture is worth a thousand words, and through the magic of the Internet I can simply show you a picture and stop fumbling for words.

View back to the cave mouth (the green in the center) from about 6 or 7 meters in.

The cave floor at this point was made up mostly of jumbled rock that had collapsed from the ceiling, and you can see the vivid red color present. This comes about because the rock cooled very rapidly, or so I've heard (anyone out there who can verify this?).

Present on the roof and walls of the cave was a mysterious silvery material that you can see in the picture as well. I don't know what this is, though I would suspect it's some kind of mineral that crystallized on the exterior of the rock as it cooled and hardened (from what I've read, it may be gypsum). It's incredibly beautiful, and reflects light in the dark cave environment like you wouldn't believe.

A picture showing the cave ceiling where some of the rock as fallen away, revealing more of the mysterious silver mineral behind it.

The lava tube also contains lots of lavacicles – which are similar to icicles, just with molten rock rather than water. They form as the lava level in the tube recedes, leaving a clear space near the top where lava can stick to the ceiling then freeze in place as it cools and drips down.

Lavacicles! Sorry about the blowout on the right there, this was my best picture of them.

Another shot of another part of the ceiling.

Once inside a little way from the entrance, the floor changed from jumbled ceiling-collapse to a slightly smoother surface made up of the last lava to flow through the tube, frozen in place in all its wrinkled glory. This type of surface is known (quaintly enough) as “cauliflower ʻaʻā.” Pure ʻaʻā generally doesn't exist in lava tubes, but this is sort of a transitional form between smooth, ropy pāhoehoe and sharp, angular ʻaʻā.

The last lava to flow through this tube, now frozen in time, makes up the floor of the cave for quite a while.

As the flow of lava from the vent cracks of Mauna Loa subsided, so did the amount of lava flowing through the tube. Eventually the last little bit didn't have enough pressure behind it to push it downhill, so it froze in place making up a rough but not unpleasant walking surface (just watch your step! Everything is moist in here).

I just want to take a moment to remark on how difficult it is to get good pictures in caves like this without enough light for the camera to be able to auto-focus. Seriously, it's really hard. You might think that the astrophotographer, who spends time taking pictures in low-light environments, might have been able to foresee this, but no. I do know to be better prepared for the future, however. I ended up not actually taking too many pictures, something I hope to remedy next time (since there was certainly no lack of things interesting enough to be photographed).

Along the side of the tube wall in places there was a sort of shelf or curb where the lava slowly cooled from the edges in as the inflow was slowing down. You can see it in the picture below:

At top you can see the cave wall, then the curb in the middle, and the cauliflower ʻaʻā floor at bottom.

One thing that helped remind us that we weren't that deep underground (all things considered) was the amount of tree roots growing down from the ceiling. There were quite a few of them in places.

Masses of tree roots hanging down over some roof-collapse rubble.

Another reminder was the presence of skylights at intervals:

Skylight in the tube. This scene looks like something you'd find in the early levels of Portal 2.

While near the skylight seen above, I found some interesting features in the floor. It looks like fossilized bits of tree bark and possibly fern leaves.

Fossilized organic material embedded in the lava making up the tube floor.

More organic material. Looks like tree bark, possibly from the abundant ʻōhiʻa lehua trees in the area.

Near the end of the cave system a breakdown in the tube let us scramble up the collapsed rock and emerge from its associated skylight. We felt that a nice walk overground was in order to get back to the car, so set off along what appeared to be a trail.

I should mention that we emerged in the middle of an ʻōhiʻa lehua forest with a lot of undergrowth of a particular fern-like plant that I didn't recognize, with no sign of civilization other than the noise of the occasional passing vehicle on Kaumana Drive. Looking on a map, I see that the exit point was no further than 300 meters (1,000 feet) from where we entered, but it felt like the middle of nowhere due to all the trees (it was also on the opposite side of the highway from where we started). The trail we were following very quickly began to appear and disappear as trails in forests are wont to due, so I had to pull out the GPS on my phone to make sure we were actually making our way back to the car.

Also very prominent on our minds was the fear of suddenly falling through a well-covered skylight hidden in the undergrowth. It wasn't always easy to determine what was solid rock footing, what was dirt or organic material, and what was leaves growing over a depression in the ground. ʻŌhiʻa trees don't really make good sticks for prodding the ground in front of you to see if it is in fact ground and not a gaping hole, so we took it slowly and carefully. Thankfully, between GPS and my good sense of direction we made it back to the parking lot where we'd parked without incident (beyond a few mosquito bites), although I'm pretty sure I was blazing my own trail for at least part of the time.

All that climbing around took a bit longer than we'd expected, and after forcing our way through the thick undergrowth we were both pretty tired, so we decided to put off exploring the makai (right-hand) side of the tube until next week, when we plan to return making use of what we learned from this expedition. (For instance, I was surprised at how warm it was in the caves, being used to thinking of caves as cool places. It was cooler than the outside air, yes, but not much, and also very humid so I worked up quite a sweat after scrambling around on rough lava rock piles for an hour and a half.)

Finally, a nice picture of one of the ʻōhiʻa trees we passed while returning:

A mature ʻōhiʻa lehua tree at about 1,000 feet elevation near the entrance to the Kaumana lava tube.