The Hawai'i That Had Never Been: A Mountain That is Younger Than Me, Mauna Ulu

Mauna Ulu, a mountain that originated between 1969 and 1974

So much of geology is incremental. A rock slides from a cliff top, a river carries sand grains downstream, a glacier slowly pushes debris down a mountain canyon. Each of these minor events add up to major changes to a landscape over millions of years: mountains disappear, lakes and seas fill with sediment, canyon gorges are carved. But to a human observer, the changes are invisible. We simply don't live long enough to see the changes that take place in geologic time.

Hawai'i, especially the Big Island, is different. The entire island is less than a million years old, not even 1/4,000th the age of the planet. Because the island sits atop a hot spot, volcanism is a near constant activity, and volcanism leads to major and rapid changes to the landscape. In this current blog series, we've been talking about the "Hawai'i That Was", the environment that existed prior to the arrival of the Europeans, and before the arrival of the Polynesians. But when we look at volcanic activity at Kilauea on the Big Island, we are looking at landscapes that have never existed before. They are new lands.

That's not to say that much is destroyed in the making of new landscapes. The basaltic lava that emanates from the vents along the flank of Kilauea's east rift does a lot of destruction as it flows towards the sea. Take a look at the mound of lava in the picture above. It's a lava tree, formed when lava flowed past a living tree, and congealed around the burning trunk. The level of the lava dropped, but not the solid material around the former tree. The original Hawaiian thought these to be the lithified bodies of humans (although the one above looks much more like a cat).   

My last post on the subject was a discussion of how kipukas preserve a bit of the world that was, prior to the eruption. I said that we visited two of them, but I later remembered that we explored two others as well. It was a trail near Chain of Craters Road that took in two volcanoes, Pu'u Huluhulu, and Mauna Ulu (this is a different Pu'u Huluhulu than the one on Saddle Road).

About 500 years ago, a mildly explosive basalt eruption produced a cinder cone now called Pu'u Huluhulu ("shaggy hill"). Over time, intense weathering of the basalt cinders produced a rich soil that allowed the growth of a rainforest. The forest covered the surrounding landscape too, but that changed not long ago. In 1969 eruptions began along the rift zone that produced lava flows for five years, the longest sustained eruption ever recorded (this record as since been broken by the current Pu'u O'o eruption that started in 1983 and is continuing today).

The lava flows filled around half of the craters along Chain of Craters Road, and covered the road too. The flows piled up against Pu'u Huluhulu as well, but weren't thick enough to overwhelm the hill and the rainforest that covered it. The forest survived as a kipuka. The trail climbs to the summit of Pu'u Huluhulu, and provides what is said to be a spectacular view of Mauna Loa, Kilauea, and Mauna Kea. I'd love to show pictures of the view, but one doesn't get to control the weather when traveling to the islands. We spent much of the hike in a rainstorm with a low cloud deck.

But there was something that we could see: a new mountain. Mauna Ulu is a 400 foot high shield volcano that came into existence while I was starting high school. It's hard to comprehend the pace of geologic change when it is incremental and slow, but it is also sometimes hard to believe how fast things can happen too. There are at least four mountains in the United States that didn't exist when I was born in 1957: Pu'u Pua'i in Kilauea Iki, Pu'u O'o, Mauna Ulu (below), and...the dome in the crater of Mt. St. Helens in Washington state! Rapid geologic change is not confined to the Big Island of Hawai'i...

The hike to the top of Pu'u Huluhulu is mostly level, with a steep climb at the end of a 1.25 mile trail from just off Chain of Craters Road in Hawai'i Volcanoes National Park. Don't miss it if you are ever in the park, and do it on a sunny day. I'd like to see the view!

Dispatches from the Road: Excuse me, there's a Kao trying to get into your Kipuka Pu'u Huluhulu...

It's hard to imagine a more spectacular setting than Saddle Road Summit on the Big Island of Hawai'i. Two of the world's largest volcanoes, Mauna Kea and Mauna Loa, overlap at an elevation of almost 7,000 feet. In the middle of the broad pass, with expansive views of both volcanoes, there is one of the most extraordinary sights of all the islands: Pu'u Huluhulu. The name means "shaggy hill". It's a small knob, a minor cinder cone lying between two giants, but it tells a fascinating story. The cinder cone erupted several thousand years ago, and has since been surrounded by barren basalt flows, most recently in the 1930s. These isolated areas surrounded by fresh lava flows are called kipukas.
On islands that have been ravaged by invasive species the way Hawai'i has, kipukas serve as islands within islands. They can preserve a native landscape that has disappeared from most of the rest of the islands. At Pu'u Huluhulu, the slopes preserve a Koa tree forest environment that once covered most of Mauna Kea, but which was decimated by logging and grazing over the last 150 years. If and when we decide to change our land-use practices on the islands, a kipuka like this one can be the source of native species that could eventually lead to the reforestation of the mountains.

Koa trees, like those seen above on the trail around Pu'u Huluhulu, once grew in abundance on the islands, reaching upwards of a hundred feet tall, and trunks wide enough to fashion canoes. Most of the "grandfather" trees have been cut down, so a place like this, with a Koa forest environment, is all the more valuable.

One cannot mistake this place as a pristine environment, though. The area was grazed heavily over the years and invasive weeds arrived on boots, and on the fur of goats, cows and pigs. The pigs and goats were especially destructive of the understory shrubs. What has changed is the growing recognition of the value of such places. A fence has been constructed to keep out the goats and pigs, and volunteers have been weeding out the invasive plant species, and planting, or encouraging the growth of dormant seeds of the native understory shrubs and perennials. They're doing a good job. The native vegetation attracts native bird and insect species, and Pu'u Huluhulu is often a good place to see the native Amakihi, Apanane, Io (Hawaiian hawk), Pueo (Hawaiian owl), Nene (the Hawaiian goose), I'iwi and other unique birds. We heard, but didn't see any close enough to photograph on this trip, but I'll be back!

We did see a rather incongruous sight, though: a herd of goats wandering across the barren lava fields (that's the "kao" of the blog title today). They know very well what lies across the fence, and they literally hang around the gateways in the fencing, hoping for a chance to get into the kipuka and do their thing, which is eating and eating. When they say "close the gates", please do it! There is grazing land across the highway for the goats.

If you have old memories of Saddle Road as a hellish, dangerous winding mountain road, or if you visit for the first time and read that the road is not for the faint of heart, the situation (for better or worse in the philosophical sense) has changed. The road has been repaved and engineered, and is a pleasant drive, if it isn't raining or foggy. Some people miss the wildness of the old route, which was pretty unnerving when I followed it for the first time. The expansive views, especially on the western slope on clear days, are stunning. It's a purely Hawaiian experience, but not a Hawai'i stereotype. There really isn't any place like this in the world.

Next time: a different kipuka...