Dr Trevor and Chris Watts (UK)
This is the first of five articles on the ‘Chain of Craters Road’ on Hawaii’s Big Island. The articles are in the form of a road trip that you can follow if you are lucky enough to go to this wonderful part of the world to see its volcanic scenery. Being a road trip in the USA, distances along the road and by foot are given in yards and miles, while measurements are provided in more European and scientific metric units.
Kilauea volcano dominates the southeast of Hawaii’s Big Island. At 1,247m high, it is by no means the biggest or highest of Hawaii’s peaks, but it is easily the most active. It doesn’t have a peak. Instead, there is a caldera – a huge, oval-shaped collapse crater that formed 500 years ago in the space of a few days – perhaps a few hours. It now measures about 5km long by 3km wide, and is 165m deep (Fig. 1).
Its appearance and dimensions have changed considerably over the years as different parts of the caldera have erupted at different times and in different ways. The most spectacular event in the past century was the 600m-high, fire-fountain episode in 1959, which filled the caldera floor with a lava lake and created the ‘side caldera’ of Kilauea Iki. The main eruptive point now is the fire pit known as Halema‘uma‘u that is located in the southwest corner of the caldera. This almost vertically-sided pit holds a semi-permanent lava lake with its surface generally around 50m below that of the main caldera floor. The depth varies, however: lava rose and overflowed onto the caldera floor several times in 2018 and 2019 because of varying pressure in Kilauea’s magma chamber.
Below the caldera, there rests a massive ‘‘summit reservoir’’ magma chamber that primarily feeds the active fire pit, directly above it. However, along a complex series of ground fractures, it also feeds several subsidiary volcanoes and volcanic vents. Some of these, such as Puʻu ʻŌʻō, have erupted for much longer than others. This, the most active volcanic region in present-day Hawaii, is known as the Eastern Rift Zone. Within this zone runs the Chain of Craters Road.
For seven miles, beginning at Kilauea’s Caldera, the road cuts through, or skirts past, many cinder and spatter cones, collapse craters, lava-tree forests, ground fissures and recently-active vents. This, the most interesting and varied section of the road, is the focus of these articles. The most significant peak the road passes is Mauna Ulu, which is a shield volcano that has built up since 1968. Swinging away from the rift zone, the Chain of Craters Road drops down the huge fault-scarp cliffs of Hilina Pali, and winds its way for another 12 miles, over multiple lava flows until it reaches the current end of the road.
This route is popular on tourist itineraries for the close-up volcanic scenery on the way to the ultimate experience of seeing the Road’s End. Coaches and day tourists stop at, perhaps, just two lay-bys to view a collapse crater and a cone at one; and a ropey (pahoehoe) lava surface with several tree moulds at another. Such brief photo opportunities do not do justice to the vistas along this marvellous stretch of road.
|A word about Hawaiian pronunciation – Hawaiians do not say ‘Morna Ulu’ for the Mauna Ulu volcano. They split most vowels up separately: thus, ‘Mah ooner Oo loo’. Similarly, ‘Kill ow eh uh’, for Kilauea; and, ‘Halley mah oomer oo’, not ‘Halley mow mow’, for Halema‘uma‘u; and, ‘Poo ooh Poo ah I’, for Pu’u Pua’i.|
Problems with access
In such an active volcanic area, it is hardly surprising that there are frequent difficulties with access. Over the years, the first and highest part of Chain of Craters Road has often been overrun and closed by lava (Fig. 2). Closures generally last for the duration of whichever eruption is current. Then the surface is rebuilt or a diversion is created.
2018 was a particularly bad year: much of Hawaii Volcanoes National Park was closed for four months. This was when the summit magma chamber partly drained, perhaps associated with the extensive outflowing of lava towards Pahoa. A series of relatively large earthquakes caused severe fracturing of the ground around the summit of Kilauea, making the cliffs around the crater rim extremely unstable. This included the area where the Jagger Museum, Visitor Centre and Ranger Centre are located (Fig. 3).
The Jagger Museum’s artefacts and exhibits were removed and the staff evacuated. It is all still closed and is likely to remain so indefinitely. Plans for any kind of replacement facility have not yet been formulated (as of mid-July 2019). The Visitor Centre, however, is open again.
Other recent closures have been because of toxic fumes, storm-fallen trees, floods of rainwater and/or lava, fissuring during earthquakes, and eruptions (Fig. 4); and most recently, efforts to eliminate infestations of fire ants. So it’s best to check before visiting – go to the dedicated site for closures and restrictions at: https://www.nps.gov/havo/closed_areas.htm.
The location of ‘Road’s End’ was not chosen by anyone – it is the point where the basaltic lava from Puʻu ʻŌʻō reached in 1986, flooding 7.5 miles of the lower road (Fig. 5). This section, parallel to the coast, continued north-easterly, parallel to the coast, into the Kalapana area of Puna District in southeast Hawaii. (The amazing variety of volcanic features in that region was the subject of my (TW) three articles in Issues 43 to 45 of ‘Deposits’.)
It has remained closed because of the continuing high risk of further massive lava flows towards the coast from Kilauea’s numerous vents and fissures along the Eastern Rift Zone, particularly Puʻu ʻŌʻō. In 2018, there were preparations to recreate this roadway as part of the evacuation plans for Puna District. This was when Puʻu ʻŌʻō again threatened to isolate or overwhelm the communities there, and cut them off from Hilo District. After three months, the lava held back within a very few feet of Highway 130 near Pahoa, and it wasn’t necessary to complete the newly-prepared escape route across the lava. Thus, it remains, as the incomplete ‘dirt’ surface, ready to receive a top dressing of tarmac when necessary.
Hawaii Volcanoes National Park is well sign-posted from Route 11. The Visitor Centre is almost immediately inside the park gates, and has always been very well worth a visit for the latest status and general information. There is also a spectacular view over the main caldera of Kilauea and into Halema‘uma‘u’s active lava pit about a mile away. It’s particularly awesome in the evenings, with the breath-taking glow from the Halema‘uma‘u pit (Fig. 6).
In the aftermath of the strongest hurricane of the 2014 season, we heard a Park Ranger busily discouraging a group from going any further because of the dangers of floods and fumes. We asked about it, and he confessed that the Park Service would much prefer it if most tourists went no further than the visitor centre – it would save them many emergency rescues of people, who have fallen, become lost or are overcome by the ‘vog’ – the volcanic fog – toxic sulphur-dioxide fumes emanating from the active vent of Halema‘uma‘u (Fig. 7).
Leave the Visitor Centre armed with maps and guides, and take the road that runs parallel to the crater rim. This very soon comes to Thurston Lava Tube (Fig. 8). It’s big and extremely popular – the extensive car park is often full, with newly-arrived coaches waiting along the road. There are better, but less accessible, lava tubes to be found, for example, at Kazamura in Puna District.
Across the road from Thurston, there are also views into the crater of Kilauea Iki (Little Kilauea) along a short trail. The views are spectacular. The trails down into the crater are sometimes open for hikers, depending mostly on wind direction – the vog can accumulate there.
A little further on from Thurston, there is a crossroads. Ahead, the Crater Rim Drive has been closed for several years, because the vog from Kilauea drifts mainly in that direction and it really is dangerous close up.
To the right, there is a road a few hundred yards long to a car park. This is the trailhead for the Devastation Trail along the rim. Anyone feeling foolhardy could probably walk the whole trail, but it’s inadvisable because of frequent toxic clouds of vog, high winds and crumbling edges. It is possible, however, to walk half a mile to the first overlook. Here, the rock is moderately compacted ash, much of it from the adjacent gently-rounded peak Pu’u Pua’i. Among the ash, it is possible to find many examples of ‘Pele’s tears’ (Fig. 9).
These are black obsidian-like drops that were exploded from eruptions in a molten state and which solidified in the air, often in beautiful teardrop-shaped forms. (These are discussed in more detail in Part 5.) Many people seem to have dug for these, judging from the numerous metre-wide holes that have been excavated (Fig. 10).
The road to the left at the crossroads is the beginning of the Chain of Craters Road. Although we (my wife, Chris, and I) have been here a number of times, several locals told us about additional features along the road, never seen by most visitors. So, we spent a day checking distances along here, from one lay-by to the next. They are marked in miles and tenths of a mile from the crossroads. Most volcanic features have a well signposted lay-by close at hand, and some have an information board, but not all of them. Set the tripmeter at zero at the crossroads and the map (Fig. 11) will tell you where to stop if the signs don’t.
In the next article, we start our road trip…
|Almost all the photographs were taken by one of us – Trevor or Chris – except the few that are credited separately. These are available as Public Domain Images from the United States Geological Service (USGS), particularly the Hawaiian Volcanoes Observatory. Innumerable Internet sites provided background information, such as dimensions of craters. The USGS is invariably helpful in answering specific queries and providing access to wider sources. Their weekly publication, ‘Volcano Watch’, is invaluable for general information as well as updates on theories, eruption activity, and trail and road closures and re-openings.|
About the authors
Trevor and Chris are keen amateur geologists living near Nottingham, England. They have climbed many volcanoes throughout the world. Sharing the exploration, photography and writing, they have had numerous articles published on the subjects of volcanoes and their other geological interest – dinosaur footprints (including in this magazine). Now retired from her work as a teacher and head teacher, Chris paints in watercolours, silks and pastels, mostly animal portraits and flowers. Trevor, formerly a teacher, headteacher and school inspector, now writes short stories and poetry for competitions, publication and the mental challenge.