RHEOGENIC CAVES AND CAVERNOUS STRUCTURES OF KALAUPAPA PENINSULA, MOLOKAI
ISLAND, HAWAII: A MARS ANALOG REVISITED
William R. Halliday1, Chris H. Okubo2, Stephan Kempe3, Michael and Sherry Garman4, and J.
Judson Wynne5.
1) Hawaii Speleological Survey of the National Speleological Society and Commission on
Volcanic Caves of the International Union of Speleology, 6530 Cornwall Court, Nashville,
TN 37205. wrhbna@bellsouth.net.
2) U.S. Geological Survey Astrogeology Science Center, 2255 Gemini Road, Flagstaff, AZ
USA 86001.
3) Institute for Applied Geosciences, University of Technology Darmstadt,
Schnittspahnstrasse 9, 64257 Darmstadt, Germany.
4) Garman Engineering Company, Nashville, Tennessee 37205.
5) SETI Institute, Carl Sagan Center, Mountain View, California 94043 and Colorado Plateau
Research Station, Northern Arizona University, Box 5614, Building 56, Suite 50, Flagstaff,
Arizona 86011.
Introduction
(Figure 1) The 2004 identification (JPL, 2004) of an unmistakable lava tube on the flank of
Olympus Mons (Figure 2) raised hope of discovery of underground refugia of Martian life forms
despite collapses evident along much of the length of this example. Further, its analogy to
“drive-in” lava tube caves on Earth (Hill, 2000) suggested the possibility of several forms of
potential underground shelter for astronauts and eventual colonists (Figure 3). The subsequent
discovery of “the Seven Sisters” pit craters on Arsia Mons (Figure 4) raised additional hopes that
perhaps one of them might open at depth into a spacious, easily accessible, underground cave
system. Reviews of documented terrestrial pit craters (Figures 5-13) with similar parameters
(Halliday and Wynne, 2008), however, indicated that field investigation of such features on
Mars is beyond the technology of the foreseeable future. While several similar pit craters on
private land on Hualalai volcano, Hawaii remain uninvestigated, aerial photography by one of us
(W.H.) revealed similar difficulties there. The present communication briefly reviews some of
the terrestrial analogs of “the Seven Sisters” documented by Favre (1993) and present Figures
5-8) and by Halliday and Wynne (2008 and present Figures 9-13) together with some of the
geological features of the subaerial part of a small basaltic shield which comprises Kalaupapa
Peninsula, Molokai Island, Hawaii (Okubo, 2001; Halliday 2001). This small area contains
features analogous to Martian features such as “the Seven Sisters” as well as other distinct
structures that deserve special attention.
Features and significance of Kalaupapa Peninsula
Celebrated Kalaupapa Peninsula demonstrates a variety of volcanic features unusual in so small
an area. Located at the north base of Molokai Island, it is the tongue-shaped summit exposure
of a largely submarine basalt shield volcano, with a subaerial surface about 4 km long, 4 km
wide at the base, and with a maximum height of about 135 m asl (Figures 14 and 15). Its lavas
are 350,000 to 550,000 years bp (Clague et al,1982). Some of these features merit detailed
study in their own right. Others merit study as potential analogs of cavernous features on
Mars.
1) Kauhako Crater (Figures 14-16) has been described by several authors (e.g., Coombs et
al, 1991). Its principal feature is Kauhako Lake (Figures 16-18), which is near the top of
a deep, water-filled open vertical volcanic conduit as defined by Skinner (1993). It has
been studied by Maciolek (1981), Donachie et al (1999, 2004), Kempe (2000, 2002) and
others. Its dimensions and morphology are basically similar to those of “the Seven
Sisters” and those of their terrestrial analogs (Halliday and Wynne, 2008). Two of the
present authors (M.G. and S.G.) have dived it to a depth of 123 meters (M. Garman,
2000; M. Garman et al, 2000; S. Garman, n.d.) and it has been plumbed to a depth of
248 meters (Maciolek, 1982). Its water is anoxic and sulfide-rich (Kempe, 2000, 2002)
and it has been described as an alkalinity pump (Kempe and Kazmierczak, 1994; Kempe,
2002). To a depth of at least 123 meters, its walls are coated by thick mats and strands
of bacteria 15 to 30 cm long. Between these and the pit walls are biogenic calcareous
deposits and some iron minerals (Figure 19). Along the lake’s perimeter, stromatolitic
crusts exist (Kempe, 2002). It thus has some of the characteristics of Mexico’s waterfilled 318-meter Zacaton Pit which has been discussed as a karstic feature adjacent to
basalt and rhyolite (e.g., Sahl, 2009).
2) Two lava tube systems (Figures 20 and 21) exist on this volcanic summit (Halliday, 2001).
Segments of the Kaupikiawa system are shown on the Okubo geological map (Figure
15). The other system is shorter. It opens high on a sea cliff about 1 km south of the
Kaupikiawa system. Here its entire cross-section is easily observed (Figure 21).
3) A large elevated primary trench with some of the characteristics of a small lunar rill
(Coombs et al, 1991) extends downslope from Kauhako Crater in a sinuous pattern near
the midline of the peninsula (Figures 14, 15, 22).
Coombs et al considered it a
collapsed lava tube cave, but it is some orders of magnitude larger than the largest
terrestrial lava tube cave on record (Halliday, 2001). In February 2000 a Hawaii
Speleological Survey team armed with machetes closely inspected approximately 99% of
its walls where breakdown-free. It discovered no trace of a relict lava tube cave of
comparable size. Instead, the team found lava levees formed by overflow from the
trench, largely concealed by dense vegetation.
4) A complex cavern (Ka Lua o Kahoalii – the Pit of Kahoalii) opens downward from the
surface of an old lava lake in the crater (Halliday, 2001). Its course (Figure 23) is just
beneath the breakdown-strewn slope of the inner crater above Lake Kauhako. It has
been discussed as if it were a lava tube cave (e.g., Coombs et al, 1991), but its pattern is
inconsistent with that of any recorded terrestrial lava tube cave and its appearance is
consistent with that of a drained portion of the feeder system of the lava pond.
Conclusions
Improving our understanding of cavernous Mars analog features will ultimately improve our
ability to model and assess the potential for cave habitability, as well as targeting caves most
suitable for establishment of underground astronaut bases on Mars. This process involves
selecting the most analogous terrestrial study sites such as the Hawaiian features discussed in
this paper. Understanding of lava tubes and collapse structures on Mars will likely benefit from
further study of analogous structures on Kalaupapa Peninsula. Continued imaging of Martian
shield volcanoes, especially in areas of poor coverage, may yield additional discoveries and
potential links to terrestrial examples. Also, further study of Kalaupapa Peninsula may yield
insights into other aspects of volcano evolution that are not Mars analogs, but merit additional
study in their own right.
References
Clague, D. et al. 1982. Age and petrology of the Kalaupapa basalt, Molokai, Hawaii. Pacific
Science, v. 36, 411-420.
Coombs, C. et al. 1991. Terrestrial analogs to Lunar sinuous rilles: Kauhako Crater and
Channel, Kalaupapa, Molokai, and other Hawaiian lava conduit systems. Proceedings of the
20th Lunar and Planetary Conference, Lunar and Planetary Institute, Houston, 1990, p. 195-206.
Donachie, S. et al. 1999. Lake Kauhako, Molokai, Hawaii: biological and chemical aspects of a
morpho-ectogenic meromicic lake. Aquatic Microbial Ecology, v. 19, 9-109.
Donachie, S. et al. 2004. The Hawaiian Archipelago: a microbial diversity hotspot. Microbial
Ecology, v. 48, 509-520.
Favre, G. 1993. Some observations on Hawaiian pit craters and relations with lava tubes. P.
37-41 in: Halliday, W., editor. Proceedings of the Third International Symposium on
Vulcanospeleology. Bend, OR, July 3-August 1, 1982. Seattle, International Speleological
Foundation.
Garman, M. 2000. Preliminary report: Research Diving, Kauhako Crater Lake, Kalaupapa
National Historical Park. 3-page typescript submitted to National Park Service, unpublished.
Garman, M. et al. 2000. First dives into Kauhako Crater Lake, Kalaupapa, Molokai, Hawaii; a
deep volcanic vent dominated by microbial life (abstract). Journal of Cave and Karst Science, v.
62, 198.
Garman, S. n.d. Deep Throat; Diving into the Kauhako Crater Lake. Advanced Diver, v. 6, n.p.
Halliday, W. 2001. Caves and cavernous features of Kalaupapa Peninsula, Molokai, Hawaii.
Report # 01-1, Hawaii Speleological Survey of the National Speleological Society. 48 p.
Halliday, W. and Wynne, J. 2008. Differentiating lava tube skylights from pit craters; a study of
the cave-like structures on Arsia Mons, Mars (abstract). Geological Society of America
(Cordilleran and Rocky Mountain Sections) Abstracts. v. 30, 33.
Hill, L. 2000. Malheur Cave (abstract). Journal of Cave and Karst Studies, v. 62, 33-34.
Jet Propulsion Laboratory of the California Institute of Technology. 2004. Photojournal. PIA:
the flows of Olympus; PIA 06935.
Kempe, S. 2000. Expedition Report, Hawaii. March 2000.
Newsletter, v. 7, 25-29.
Hawaii Speleological Society
Kempe, S. 2002. Alkalinity pump and carbonate precipitation: a comparison of the crater lakes
of Kauhako Crater, Hawaii, Satonda, Indonesia, and Niuafo’ou, Tonga (abstract). Abstracts
Volume, 6th International Symposium on the Geochemistry of the Earth’s Surface (GES-6). May
20-24. 2002. Honolulu, Hawaii, USA.
Kempe, S. and Kazmierczak., J. 1994. The role of alkalinity in the evolution of ocean chemistry,
organization of living systems and biocalcification processes. In: F. Doumenge. editor. Past
and Present Biomineralization Processes: Considerations about the Carbonate Cycle. Bulletin
of the Institute of Oceanography, Monaco. Special Number 13, 61-117.
Maciolek, J. 1982. Lakes and lake-like waters of Hawaii. B.P. Bishop Museum Occasional Paper
25, 1-14.
Okubo, C. 2001. Preliminary geologic map of Kalaupapa Peninsula, Molokai, Hawaii. Page 4 in
Halliday 2001, q.v.
Sahl, J. et al. 2009. An autonomous robotic exploration of deep phreatic sinkholes reveals a
wealth of microbial diversity. P. 48-09 in: White, W., editor. Proceedings, 15th International
Congress of Speleology, Kerrville, Texas, USA. July 19-26.
Skinner, 1993. Open vertical volcanic conduits: a preliminary investigation of an unusual
volcanic form with examples from Newberry Volcano and the central High Cascades of Oregon.
P. 7-17 in: Halliday, W., editor. Proceedings of the Third International Symposium on
Vulcanospeleology, Bend, Oregon, USA. July 30-August 1, 1982. Seattle, International
Speleological Foundation.
Acknowledgments
This is a report of the Hawaii Speleological Survey of the National Speleological Society and
several of its members and cooperators participated in this field work. Without the cordial
assistance of Jim Martin and Dean Alexander (then Superintendents of Hawaii Volcanoes
National Park and Kalaupapa National Historical Park, respectively), and of Rick Robinson of
Kamehameha Schools (owner of the summit ridges of Hualalai volcano), much of this field work
would not have been possible. Jeff Trainer and other staff persons of both national parks
notably assisted in the field work. Jack Lockwood and staff persons of the USGS Hawaiian
Volcano Observatory and of the Kahuku Ranch participated in the investigation of Hapai Mamo
Pit. Gerald Favre supplied diagrams and photographs of Wood Valley Pit Crater and the Kau
Desert Pit Craters. Carol Vesely supplied the photograph of the Tyrolean traverse of Na One Pit.
Suggestions by Laszlo Kesthelyi notably improved the abstract, and Jody Bailey of the Nashville
Grotto of the National Speleological Society provided much-needed electronic expertise. We
are profoundly grateful to all.