A Most Misunderstood Island: One of the Most Diverse Landscapes on Earth

Shall we start with a stereotypical Hawaiian beach?

One can certainly be forgiven for thinking that Hawai'i is a group of high-rise hotels next to a wide sandy beach. It isn't as if a string of television shows (Magnum, P.I. and Hawaii 5-0 for example) have spent decades putting that stereotype into our heads. And the majority of tourists never venture beyond the hotel row at Waikiki and Honolulu. A visit to some of the other islands can be a real revelation (and adventure). The Hawaiian Islands, and especially the Big Island, are one of the most diverse landscapes on planet Earth.

The view from Pu'u Huluhulu at Saddle Road summit

Not convinced? Here is a selection of pictures taken over just two days of reconnaissance on the Big Island. How about an African savanna? A lone Koa tree (I think, I'm still learning these!) overlooks the plains along the summit of Saddle Road, a highway that links the two sides of the island. There are even grazing cattle, sheep, pigs, and goats (which are doing terrible things to the natural ecosystems).

Perhaps an archaeological site in the wilds of the Sinai Desert? The great heiaus on the Big Island served a variety of purposes, including refuges, sacrificial sites, and temples. They date back hundreds of years. This one can be seen at Pu'ukohola Heiau National Historical Site on the dry side of the island in the rain shadow of the Kohala volcano. Rainfall averages less than 20 inches a year, compared to more than a hundred just a few miles away.

A recovering mesic coastal forest? Not a desert, not a rainforest, but somewhere in-between (mostly on the dry side) We are looking at the Lapakahi State Historical Park on the west slope of Kohala. The original forest was cut down for a number of reasons, but humans lived in this village for hundreds of years.

How about the high plains prairie? One of the largest privately owned ranches in the United States is found on the Big Island (the Parker Ranch). The cattle graze on rich grasslands that cover some of the older volcanoes. When they reach the right age, they fly in a 747 to the mainland. As a guide to Hawaii mentions, they probably enjoy more foot room than the average tourist in coach...

 As can be seen, some of the grasslands are windy.

Big Sur on the Big Island? Sure. This Big Island is not as famed for the coastal cliffs like those in Kaua'i and Molokai, but several tens of thousands of years ago, a large part of the northern coastline of the island collapsed into the sea. It probably produced a mega-tsunami in the local islands that had run-ups amounting to hundreds of feet in elevation.The Pololu Valley and coast is stunning.

The Pololu coast is also known for the gorgeous river valleys that extend into the Kohala volcano ("gorgeous"; Did you get it?). The canyons are hundreds of feet deep, and were once even deeper, but the islands are slowly sinking and the valleys fill with sediment.

I doubt that Sauron would have ever established Mordor in a place like this. These a'a lava flows from Mauna Loa are only a few decades old, and are practically impossible to traverse. Somehow a highway got built across part of it, and there is even a strange housing complex in the immediate vicinity. The few trees are the native Ohi'a, a tree that can grow from coastal environments to as high as 10,000 feet or so. I don't believe there is another tree on the planet that can do that.

And how about glacial environments? Yes, Hawai'i had glaciers during the Ice Ages! The top of Mauna Kea was mantled with flowing ice only a few thousand years ago. There are glacial moraines, and even a small lake that is the third highest in United States. Eruptions happening in the ice produced a glassy form of basalt that was much harder than normal, so the native Hawaiians would climb to the summit of the mountain to gather the rock for tool-making.

And finally, yes, there are rainforests! Beautiful green forests filled with rare and endemic plants found nowhere else on the planet. Don't tell anyone about this, but I see scenes like this and think of the Jungle Cruise at Disneyland! But these forests are real.

There are even more ecosystems and biomes on the island that we just didn't happen to see on our short excursions. Expect to see some more as the week progresses. We've got two more weeks on the islands, and lots of exploring to do!

Want to see classic volcano features in California? Check out Lava Beds National Monument...

At least when the Republicans come to their senses and reopen the government. The park is closed right now.

Lava Beds National Monument was one of the central locales for our exploration of the northern California Cascades on our recent field studies class. The park was established on the northern flank of Medicine Lake Highland, a shield-like edifice that is the most voluminous volcano in California (about 130 cubic miles of lava as compared to 108 at Mt. Shasta). The park is known primarily for the richness and variety of its lava tubes, and for being the ancestral homeland of the Modoc People, who fought against impossible odds for the right to live on the land in 1872 and 1873. They lost everything.

Lava Beds is also one of the best places I know of outside of Hawaii to see the classic features of basaltic lava flows. The park preserves a number of extensive flows, some as young as 1,150 years. In the dry high desert environment, they look as if they erupted yesterday.

We drove up the park road from Captain Jack's Stronghold and found a marvelous example of an a'a lava at the Devil's Homestead flow, which erupted about 12,000 years ago (above). I was trying to imagine crossing the lava flow barefoot, saying "ah, ah" the whole way. Basalt is often quite liquid (non-viscous), but with distance and dropping of temperature, the lava can crust over and break up into a blocky rough surface.

A short distance later we encountered one of the youngest flows in the park, the Black Crater flow, dated to about 1,250 years ago. The short trail to the spatter cone crosses some excellent examples of pahoehoe flows, formed by basalts that had low viscosity .

Black Crater is actually quite colorful. It is not really a crater at all, but is instead a group of spatter cones, which formed as lava droplets popped out of the vents, forming small cones of popcorn shaped basalt.

A bit further up the road we found the Fleener Chimneys, a group of spatter cones that were the source of the large Devil's Homestead flow, seen in the first picture. The Dragon's Mouth is a small lava tube opening that provides a clue of how basalt lavas can flow for many miles. They crust over into well-insulated channels.

There are nicely developed spatter cones at the Chimneys, that like the other features we'd seen, looked as if they erupted practically yesterday instead of 12,000 years ago.

The pahoehoe flows seem to still retain a glassy veneer, a feature that is quickly lost in more humid environments.

Three vents from the Devil's Homestead flow can still be seen (the "chimneys"). One was originally 50 feet deep. Morons over the years kept throwing rocks in the hole, filling it. Volunteers recently pulled 35 TONS of rocks from this particular chimney. Looking down the vent made me think of the Sarlaac in Star Wars...

Our next stop was our first exploration of the lava tube system. The 3/4 mile stroll to Big Painted Cave offered an excellent view of Schonchin Butte, a classic cinder cone, one of many scattered across the flanks of Medicine Lake Highland.

Up next...going underground in Lava Beds!

The Other California: Waiter! There's A'a in my Pahoehoe!

Medicine Lake Highland is one of the finest places in California to compare and contrast volcanic landforms, lava flows, and pyroclastic debris. The volcano has erupted a complete range of different lavas in the last few thousand years, from silica-poor basalt to silica-rich rhyolite, resulting in the presence on the mountain of practically every kind of volcanic landform: a shield, cinder cones, plug domes, a caldera and tuff cones. And every kind of lava flow....

Today we are looking at basalt flows. Basalt can be highly fluid (non-viscous), forming smooth-surfaced flows that ancient Hawaiians compared to shark skin. When such lavas flow over edges, they form structures that look like coiled rope, as seen in the photo below. These are called pahoehoe lavas ("pa-hoy-hoy"). I have to admit I took the photo in Hawaii on the 1974 Maunu Ulu flow, not at Medicine Lake. As many times as I have visited Medicine Lake Highland, I have failed all those times to simply look down and take a picture of some pahoehoe lava...

As the lava cools, or if it has a different gas or silica content, the basalt lava can become more viscous. As it flows, it crusts over and the unstable surface breaks up repeatedly into an uneven rubble, even as the interior remains hot and molten. The Hawaiians called these a'a lavas ("ah-ah"). Some a'a is visible on the right side of the photo above, and fills the picture below. This shot is the Devils Homestead Flow in Lava Beds National Monument on the north flank of Medicine Lake Highland. It erupted around 12,000 years ago from an area in Lava Beds called the Fleener Chimneys.

The youngest basalt lava in Lava Beds National Monument, the Callahan flow, originated at Cinder Butte just south of the monument only about 1,100 years ago. A small quarry (below)reveals a cross section of an a'a flow, with the rubbly base, a solid interior, and the rubbly surface (a sketch map showing the location of Cinder Butte and the Callahan flow can be found in yesterday's post; it's a narrow dirt road, but accessible to cars with reasonable clearance). The barren surface of Cinder Butte is a wonderful example of a young cinder cone, formed as small fragments of lava (cinders) were explosively ejected from the eruption site.

A'a and pahoehoe flows can show transitional forms. In the photo below, from Black Crater in Lava Beds, the pahoehoe surface was beginning to break up as it congealed, forming slabby pahoehoe. This particular flow is probably only a few decades older than the Callahan Flow.

Medicine Lake Highland also has silica-rich rhyolite lavas. We will explore these in the next post.

In the interest of full disclosure, I stole today's title quip from an absolutely fantastic DVD called Lava Flows and Lava Tubes which is one of the best movies I have ever seen illustrating the dynamics of lava flows. It intersperses active Hawaiian flows with volcanic locales across the western United States, including Lava Beds. If you are curious about lava flows or are a teacher, it is a great resource.