There are many wondrous, enigmatic and fascinating attractions on the Big Island of Hawaii, some better known than others, many out of the way and generally off the beaten track. Tour Guide Hawaii has produced an encyclopedic collection of the most up-to-date information, presented as short GPS-cued videos, in an app downloadable to iPhone and iPod Touch that covers the entire Big Island, highlighting the popular and the uncrowded, the famous and the secluded, the adventurous and the relaxing.
Although it is the most active volcano on earth, many visitors to Hawaii Volcanoes National Park standing on the very summit of Kilauea Volcano often stare and wonder “Where’s the volcano?” Nestled snugly up against Mauna Loa, and not as vertically spectacular as either this near neighbor or Mauna Kea, Kilauea doesn’t even appear to be a bump on the landscape from the usual viewpoints. Even though it doesn’t standout visually, Kilauea is one of the most intriguing and fascinating volcanoes on earth…let’s just take a quick look at some of the reasons why.
Comprising the entire southeastern portion of Hawaii Island, Kilauea Volcano is not only currently the world’s most active volcano, it is also the home of the fire-goddess Pele. Early geologists believed Kilauea was merely a satellite vent of Mauna Loa, as it lies directly on that mountain’s southern slopes. However, Kilauea is now recognized as its own, distinct, volcano which has its own, separate, magma source and unique plumbing.
Presenting the classic “Hawaiian Shield Volcano” shape, a basic oval with low, shallow slope angles, volume-wise Kilauea is one of the the world’s most massive mountains. Standing 1240 meters (4080) above sea level, the above-ocean part of the volcano is about 80 km (50 miles) long and 32 km, (20 miles) wide, along an axis trending roughly southwest to northeast. However, like all the other Hawaiian volcanoes, the great majority of its vast bulk lies below the sea, about 5.5 km (18,000 feet) deep here, making Kilauea’s true base-to-summit height about 7 km (23,000 ft).
Sometimes vying with Mts. Aetna and Stromboli for the title of “most active volcano on earth”, Kilauea has been erupting continuously since January 1983; between then and June 2009, nearly 700 acres of new land was created on Hawaii Island by Kilauea lava flows. As the time scale of human lives and human tragedy are so much shorter than geologic time scales, and thus human memories of past disasters grow dim rather rapidly, this volcanic growth has come at quite a cost because people insist on building villages, towns and roads on this highly active landscape. In recent decades, the towns of Kapoho (in 1960), Kalapana (in 1990), and Kaimu (in 1990) have all been burned, buried and destroyed by Kilauea, and now are seemingly all but abandoned except by a few hardy souls. Although popularly thought to be rather tame with fairly peaceable eruptions, Kilauea in the past has had its fair share of explosive, violent, phreatomagmatic eruptions, spewing great quantities of ash as well.
Kilauea owes its peculiar shape to two long rift systems, the currently active East Rift and the Southwest Rift. These rifts are comprised of huge, deep fractures through the bulk of the mountain. Magma rises from deep below the volcano to a pool just below the summit caldera, then flows through internal plumbing down either rift, causing flank eruptions at vents down-rift. These flank eruptions greatly enhance Kilauea’s exaggerated elongate shape. In recent times, many more eruptions have occurred along the East Rift, than the Southwest Rift.
The orientation of these rifts is controlled by the geography of Mauna Loa and Kilauea, as well as by gravity. Because the north side of Kilauea is well buttressed by the huge mass of Mauna Loa and the unsupported south side slopes-off into the sea, the very mass of Kilauea is pulling it down slope, into the sea. Indeed, the sub-sea, southern slope of Kilauea is a vast, hummocky field of debris from enormous landslides. Above sea level, this slumping activity is evidenced by the several, sub-parallel ridges (or “Pali”, in Hawaiian) on the southern flank. With throws of much as 430 meters (1400 feet), these faults represent the massive fracturing of the volcano’s southern flank and the subsequent slumping of these giant blocks down slope. A drive down the Holei Pali along Chain of Craters Road will quickly demonstrate the magnitude of seaward movement as Kilauea erupts, slumps and grows.
Seaward slumping is exacerbated by the volcanic activity itself; as Kilauea fills with magma, it swells and slumps southward, producing massive earthquakes and landslides. The slumping, however, also exacerbates the volcanic activity. By opening-up new voids in Kilauea’s internal plumbing, the slumping allows injection of even more magmatic material into Kilauea, which then causes more earthquakes and more slumping. Essentially spreading under its own enormous weight, the synergy between magma injection and slumping allows Kilauea to grow both by eruption of, and intrusion of, magma.
The supply of magma to the volcano is fairly consistent at 1.8 cubic km (1.0 cubic miles) per year, however forty to fifty per cent of the melt never makes its way to the surface. Called “endogenous growth”, nearly half the growth of Kilauea can be attributed to magma cooling and solidifying below ground, in the growing voids opened by the synergistic magma injection and seaward slumping of the mountain.
Conjoined on its northern flank by the vastly larger Mauna Loa, Kilauea doesn’t appear to the casual observer to have a true summit. However, the summit region, around which Crater Rim Drive circles, is comprised of a larger collapse crater (Kilauea Caldera), which contains three smaller collapse craters (Halema’uma’u, Keanakako’i and Kilauea Iki Craters). Collapse craters, such as here and those along Chain of Craters Road, are formed when magma is withdrawn from a reservoir during an eruption, and the suddenly unsupported land above simply collapses into the void. As you look out over the enormous cavity formed by Kilauea Caldera, imagine the immensity of the eruptive event that left enough of a void in the magma chamber to allow this huge crater to form.
Kilauea’s large magma pool lies just below the summit region, somewhat south of Halema’uma’u Crater, at a depth of about 1.5-5 km (1-3 miles). Forming a magma reservoir several kilometers wide, it acts as central storage for the entire summit-rift magma plumbing system. Partial melting in the mantle at a depth of 40-60 km (52-30 miles) produces magma which rises through the earth and pools within a couple kilometers or so of the surface, and which then flows almost immediately to the site of eruption (summit or flank), having very little residence time within the volcano itself. This “open door to the mantle” feature is a fairly unique to Kilauea Volcano.
Based on eruptive patterns in recorded history, Kilauea has been observed to follow three shifting modes of eruptive behavior. The first mode involves explosive volcanism at Kilauea’s summit. This activity contributed to the formation of past and present calderas in the summit area as well as having showered Ka’u with a cover of cinder and ash. The second mode is continuous effusive eruptive activity at the summit. This mode is typified by features such as the former lava lake at the summit which was present well into historic times, and events such as voluminous outpouring of lava from several summit vents. This mode tends to fill-in summit calderas and produce a landscape of broad, coalescing shields atop the various vents. The third mode of eruption is the continuous flank eruption, as seen today on the East Rift at vents such as Pu’u O’o and Kupaianaha.
These modes are derived from observation of the volcano’s activity only during modern times, and almost certainly Kilauea’s behavior over geologic time must be much more complex. Rather than a view of the evolution of Kilauea Volcano, these modes may serve more as template through which to view what the volcano is capable of doing. It has been observed that periods of volcanic quiescence, or of small eruptions which shift location from summit to flank, may herald a shift in these eruptive modes. Further, it has been suggested based on recent observations that large, south-flank earthquakes initiating magma intrusion can greatly alter eruptive modes.
So, now that we understand a little of the mystery and complexity of Kilauea Volcano, where is the best place to see it from? For starters, one cannot beat the view off the back porch of Volcano House in Hawaii Volcanoes National Park, which encompasses much of Kilauea Caldera and Halema’uma’u Crater. Although currently closed between Jagger Museum and the intersection with Chain of Craters Road because of the ongoing eruption in Halema’uma’u Crater, the portion of Crater Rim Drive which is open provides a unique view of the volcano in a scenic loop around the entire summit region. Of particular interest are the stops at Steaming Bluff, Jagger Museum, Halema’uma’u Crater (closed), Southwest Rift Zone (closed), Keanakako’i Crater (closed), and Kilauea Iki Crater Overlook.
Driving across the summit dome and down to the slump-block cliffs on Hilina Pali Road takes you on a fabulous backcountry exploration from a nether-world of volcanic destruction and to lush, tropical dryland forest and savanna. Hikes along Devastation Trail, through Kilauea Iki Crater and out to the caldera overlook at Waldron Ledge give fabulous insight to Kilauea Volcano and are particularly beautiful as well as fascinating, and fairly easy for those in reasonable physical condition.
Aside from the summit region, the Chain of Craters Road travels through the most interesting geography of Kilauea, including lava flows from numerous recent eruptions. Although everywhere fascinating, stops at Pauahi Crater, Mauna Ulu and Muliwai O Pele are almost mandatory. As mentioned earlier, this drive gives stark perspective on the slump blocks and the slippage of Kilauea’s south flank toward the sea. Stops at Kealakomo Overlook, Halona Kahakai, Alanui Kahiko and Holei Pali illustrate the vast nature of the slow creep of Kilauea’s southern flank down-slope. A stop to see the amazing, ancient petroglyphs at Pu’u Loa Petroglyph Field provides a moving, human connection to the peoples of the past, the awe and respect they had for this Goddess and her mountain home. The end of Chain of Craters Road gives way to a playground of geological landscapes, booming sea cliffs and ancient villages, as well as providing the jumping-off point for hikes to see the flowing lava, when it is flowing within the Park boundaries.
A complete guide to exploring Hawaii Volcanoes National Park can be found here; you should plan to spend the better part of a full day in the park—unless you’ve been here before, it will be the most interesting place you’ve ever been to yet. Viewing the flowing lava, the spectacle of the earth remaking herself, is one of the most moving, soul-filling, surprisingly emotional experiences you can have. The current eruption in Halema’uma’u Crater, although it hasn’t yet produced any lava flows, is best viewed from the Jagger Museum; at times of peak activity, it is most spectacular when viewed after dark. Guides to Lava Viewing in the Park and at the County of Hawaii Lava Viewing platform east in Puna at Waikupanaha can be found here and here respectively. A general outline of the volcanoes of Hawaii Island is presented here, a brief discussion on the differences between a’a and pahoehoe lavas can be found here, and an overview geologic history of the Hawaiian Islands can be found here.
Perhaps no other volcano in the world, certainly no active volcano, is so easy to explore, to touch, to experience. If you come to see Kilauea, home of the Goddess Pele, be sure to give yourself a lot of time—you’ll be more captivated than you expect; certainly you’ve never experienced anything like this before. Come, explore, enjoy, stand at her door and breath the breath of the Fire Goddess.
To see the new iPhone/iPod Touch App, please visit http://www.tourguidehawaii.com/iphone.html.
The best of Tour Guide Hawaii’s free content about traveling to, and exploring, the Big island, can be found here.
All media copyright 2010 by Donald B. MacGowan. All rights reserved.