Articles | Volume 9, issue 2
https://doi.org/10.5194/esurf-9-145-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/esurf-9-145-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The enigma of relict large sorted stone stripes in the tropical Ethiopian Highlands
Alexander R. Groos
CORRESPONDING AUTHOR
Institute of Geography, University of Bern, 3012 Bern, Switzerland
Janik Niederhauser
Institute of Geography, University of Bern, 3012 Bern, Switzerland
Luise Wraase
Department of Geography, Philipps University of Marburg, 35032 Marburg, Germany
Falk Hänsel
Department of Geography, Philipps University of Marburg, 35032 Marburg, Germany
Thomas Nauss
Department of Geography, Philipps University of Marburg, 35032 Marburg, Germany
Naki Akçar
Institute of Geological Sciences, University of Bern, 3012 Bern,
Switzerland
Heinz Veit
Institute of Geography, University of Bern, 3012 Bern, Switzerland
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Cited articles
Aldiss, D. T. and Edwards, E. J.: The Geology of the Falkdland Islands,
British Geological Survey Technical Report WC/99110, British Geological Survey, Keyworth, Nottingham, UK, available at:
http://nora.nerc.ac.uk/id/eprint/507542/1/WC99010.pdf (last access: February 2021), 1999. a
Ball, D. F. and Goodier, R.: Large Sorted Stone-Stripes in the Rhinog Mountains, North Wales, Geogr. Ann. A, 50, 54–59, https://doi.org/10.2307/520871, 1968. a, b
Balme, M., Gallagher, C., Page, D., Murray, J., and Muller, J.-P.: Sorted Stone Circles in Elysium Planitia, Mars: Implications for Recent Martian Climate, Icarus, 200, 30–38, https://doi.org/10.1016/j.icarus.2008.11.010, 2009. a
Barrows, T., Stone, J. O., and Fifield, L. K.: Exposure Ages for Pleistocene Periglacial Deposits in Australia, Quaternary Sci. Rev., 23, 697–708, https://doi.org/10.1016/j.quascirev.2003.10.011, 2004. a
Bertran, P., Klaric, L., Lenoble, A., Masson, B., and Vallin, L.: The Impact of Periglacial Processes on Palaeolithic Sites: The Case of Sorted Patterned Grounds, Quatern. Int., 214, 17–29, https://doi.org/10.1016/j.quaint.2009.10.021, 2010. a
Boelhouwers, J., Holness, S., and Sumner, P.: The Maritime Subantarctic: A
Distinct Periglacial Environment, Geomorphology, 52, 39–55,
https://doi.org/10.1016/S0169-555X(02)00247-7, 2003. a, b, c
Chandler, B. M., Lovell, H., Boston, C. M., Lukas, S., Barr, I. D.,
Benediktsson, Í. Ö., Benn, D. I., Clark, C. D., Darvill, C. M.,
Evans, D. J., Ewertowski, M. W., Loibl, D., Margold, M., Otto, J.-C., Roberts, D. H., Stokes, C. R., Storrar, R. D., and Stroeven, A. P.: Glacial
Geomorphological Mapping: A Review of Approaches and Frameworks for Best
Practice, Earth-Sci. Rev., 185, 806–846, https://doi.org/10.1016/j.earscirev.2018.07.015, 2018. a
Clapperton, C. M.: Evidence of Cirque Glaciation in the Falkdland Islands, J. Glaciol., 10, 121–125, https://doi.org/10.3189/S0022143000013058, 1971. a, b
Clapperton, C. M. and Sudgen, D. E.: The Maximum Extent of Glaciers in Part of West Falkland, J. Glaciol., 17, 73–77, https://doi.org/10.3189/S0022143000030732, 1976. a, b
Conway, D.: The Climate and Hydrology of the Upper Blue Nile River, Geogr. J., 166, 49–62, https://doi.org/10.1111/j.1475-4959.2000.tb00006.x, 2000. a
Costa, K., Russell, J., Konecky, B., and Lamb, H.: Isotopic Reconstruction of
the African Humid Period and Congo Air Boundary Migration at Lake Tana, Ethiopia, Quaternary Sci. Rev., 83, 58–67,
https://doi.org/10.1016/j.quascirev.2013.10.031, 2014. a, b
de Deus Vidal Junior, J. and Clark, R. V.: Afro-Alpine Plant Diversity in
the Tropical Mountains of Africa, Encyclopedia of the World's Biomes, Elsevier, Amsterdam, the Netherlands, 1–22, https://doi.org/10.1016/B978-0-12-409548-9.11885-8, 2019. a
Francou, B. and Bertran, P.: A Multivariate Analysis of Clast Displacement
Rates on Stone-banked Sheets, Cordillera Real, Bolivia, Permafrost Periglac. Process., 8, 371–382, https://doi.org/10.1002/(SICI)1099-1530(199710/12)8:4<371::AID-PPP263>3.0.CO;2-7, 1997. a
Francou, B., Méhauté, N. L., and Jomelli, V.: Factors Controlling
Spacing Distances of Sorted Stripes in a Low-Latitude, Alpine Environment
(Cordillera Real, 16∘ S, Bolivia): Spacing Distances of Sorted Stripes in the Cordillera Real, Permafrost Periglac. Process., 12, 367–377, https://doi.org/10.1002/ppp.398, 2001. a, b
Galloway, R. W.: Late Quaternary Climates in Australia, J. Geol., 73, 603–618, https://doi.org/10.1086/627096, 1965. a
Gebrechorkos, S. H., Hülsmann, S., and Bernhofer, C.: Long-Term Trends in
Rainfall and Temperature Using High-Resolution Climate Datasets in East Africa, Sci. Rep., 9, 1–9, https://doi.org/10.1038/s41598-019-47933-8, 2019. a
Gindraux, S., Boesch, R., and Farinotti, D.: Accuracy Assessment of Digital Surface Models from Unmanned Aerial Vehicles' Imagery on Glaciers, Remote Sens., 9, 1–15, https://doi.org/10.3390/rs9020186, 2017. a
Grab, S.: Glacial and Periglacial Phenomena in Ethiopia: A Review, Permafrost Periglac. Process., 13, 71–76, https://doi.org/10.1002/ppp.405, 2002. a, b
Groos, A. R., Bertschinger, T. J., Kummer, C. M., Erlwein, S., Munz, L., and
Philipp, A.: The Potential of Low-Cost UAVs and Open-Source Photogrammetry Software for High-Resolution Monitoring of Alpine Glaciers: A Case Study from the Kanderfirn (Swiss Alps), Geosciences, 9, 1–21, https://doi.org/10.3390/geosciences9080356, 2019. a, b
Hallet, B.: Stone Circles: Form and Soil Kinematics, P. Roy. Soc. A, 371,
1–17, https://doi.org/10.1098/rsta.2012.0357, 2013. a, b, c, d
Hallet, B., Sletten, R., and Whilden, K.: Micro-Relief Development in Polygonal Patterned Ground in the Dry Valleys of Antarctica, Quatern. Res., 75, 347–355, https://doi.org/10.1016/j.yqres.2010.12.009, 2011. a
Harris, S. A. and Pedersen, D. E.: Thermal Regimes beneath Coarse Blocky
Materials, Permafrost Periglac. Process., 9, 107–120, 1998. a
Hedberg, O.: Vegetation belts of East African Mountains, Svensk bot Tidskr, 45, 140–202, 1951. a
Hendrickx, H., Jacob, M., Frankl, A., Guyassa, E., and Nyssen, J.: Quaternary
Glacial and Periglacial Processes in the Ethiopian Highlands in Relation to the Current Afro-Alpine Vegetation, Z. Geomorphol., 59, 37–57,
https://doi.org/10.1127/0372-8854/2014/0128, 2014. a
Ivy-Ochs, S., Synal, H.-A., Roth, C., and Schaller, M.: Initial Results from
Isotope Dilution for Cl and 36Cl Measurements at the PSI/ETH
Zurich AMS Facility, Nucl. Instrum. Meth. B, 223–224, 623–627, https://doi.org/10.1016/j.nimb.2004.04.115, 2004. a
Ivy-Ochs, S., Kerschner, H., Maisch, M., Christl, M., Kubik, P. W., and
Schlüchter, C.: Latest Pleistocene and Holocene Glacier Variations in the European Alps, Quaternary Sci. Rev., 28, 2137–2149,
https://doi.org/10.1016/j.quascirev.2009.03.009, 2009. a
James, M. R. and Robson, S.: Mitigating Systematic Error in Topographic Models Derived from UAV and Ground-Based Image Networks, Earth Surf. Proc.
Land., 39, 1413–1420, https://doi.org/10.1002/esp.3609, 2014. a
Juliussen, H. and Humlum, O.: Thermal Regime of Openwork Block Fields on the
Mountains Elgåhogna and Sølen, Central-Eastern Norway, Permafrost Periglac. Process., 19, 1–18, https://doi.org/10.1002/ppp.607, 2008. a
Kaser, G., Hardy, D. R., Mölg, T., Bradley, R. S., and Hyera, T. M.: Modern Glacier Retreat on Kilimanjaro as Evidence of Climate Change:
Observations and Facts, Int. J. Climatol., 24, 329–339,
https://doi.org/10.1002/joc.1008, 2004. a
Kessler, M. A. and Werner, B. T.: Self-Organization of Sorted Patterned Ground, Science, 299, 380–383, https://doi.org/10.1126/science.1077309, 2003. a, b, c, d
Kessler, M. A., Murray, A. B., Werner, B. T., and Hallet, B.: A Model for
Sorted Circles as Self-Organized Patterns, J. Geophys. Res., 106, 13287–13306, https://doi.org/10.1029/2001JB000279, 2001. a, b
Křížek, M., Krause, D., Uxa, T., Engel, Z., Treml, V., and
Traczyk, A.: Patterned Ground above the Alpine Timberline in the High Sudetes, Central Europe, J. Maps, 15, 563–569, https://doi.org/10.1080/17445647.2019.1636890, 2019. a, b
Lemma, B., Mekonnen, B., Glaser, B., Zech, W., Nemomissa, S., Bekele, T.,
Bittner, L., and Zech, M.: Chemotaxonomic Patterns of Vegetation and Soils
along Altitudinal Transects of the Bale Mountains, Ethiopia, and Implications for Paleovegetation Reconstructions – Part II: Lignin-Derived Phenols and Leaf-Wax-Derived n-Alkanes, Quaternary Sci. J., 68, 189–200, https://doi.org/10.5194/egqsj-68-189-2019, 2019. a
Lemma, B., Kebede Gurmessa, S., Nemomissa, S., Otte, I., Glaser, B., and Zech, M.: Spatial and Temporal 2H and 18O Isotope Variation of Contemporary Precipitation in the Bale Mountains, Ethiopia, Isotop. Environ. Health Stud., 56, 1–14, https://doi.org/10.1080/10256016.2020.1717487, 2020. a, b
Levin, N. E., Zipser, E. J., and Cerling, T. E.: Isotopic Composition of Waters from Ethiopia and Kenya: Insights into Moisture Sources for Eastern Africa, J. Geophys. Res., 114, 1–13, https://doi.org/10.1029/2009JD012166, 2009. a, b
Lifton, N., Sato, T., and Dunai, T. J.: Scaling in Situ Cosmogenic Nuclide
Production Rates Using Analytical Approximations to Atmospheric Cosmic-Ray
Fluxes, Earth Planet. Sc. Lett., 386, 149–160, https://doi.org/10.1016/j.epsl.2013.10.052, 2014. a, b
Mangold, N.: High Latitude Patterned Grounds on Mars: Classification,
Distribution and Climatic Control, Icarus, 174, 336–359,
https://doi.org/10.1016/j.icarus.2004.07.030, 2005. a
Marrero, S. M., Phillips, F. M., Borchers, B., Lifton, N., Aumer, R., and
Balco, G.: Cosmogenic Nuclide Systematics and the CRONUScalc Program, Quatern. Geochronol., 31, 160–187, https://doi.org/10.1016/j.quageo.2015.09.005, 2016. a, b
Matsuoka, N.: Temporal and Spatial Variations in Periglacial Soil Movements on Alpine Crest Slopes, Earth Surf. Proc. Land., 30, 41–58,
https://doi.org/10.1002/esp.1125, 2005. a, b
Messerli, B. and Winiger, M.: Climate, Environmental Change, and Resources of the African Mountains from the Mediterranean to the Equator, Mt. Res. Dev., 12, 315–336, https://doi.org/10.2307/3673683, 1992. a
Miller, R., Common, R., and Galloway, R. W.: Stone Stripes and Other Surface Features of Tinto Hill, Geogr. J., 120, 216–219, https://doi.org/10.2307/1791537, 1954. a
Mohr, P.: Ethiopian Flood Basalt Province, Nature, 303, 577–584,
https://doi.org/10.1038/303577a0, 1983. a
Mulheran, P. A.: Theory of Self-Organisation in Sorted Stone Stripes, J. Phys., 4, 1–5, 1994. a
Nicholson, F. H.: Patterned Ground Formation and Description as Suggested by Low Arctic and Subarctic Examples, Arct. Alp. Res., 8, 329–342, https://doi.org/10.2307/1550437, 1976. a
Ossendorf, G., Groos, A. R., Bromm, T., Tekelemariam, M. G., Glaser, B., Lesur, J., Schmidt, J., Akçar, N., Bekele, T., Beldados, A., Demissew, S., Kahsay, T. H., Nash, B. P., Nauss, T., Negash, A., Nemomissa, S., Veit, H., Vogelsang, R., Woldu, Z., Zech, W., Opgenoorth, L., and Miehe, G.: Middle
Stone Age Foragers Resided in High Elevations of the Glaciated Bale Mountains, Ethiopia, Science, 365, 583–587, https://doi.org/10.1126/science.aaw8942, 2019. a
Richmond, G. M.: Stone Nets, Stone Stripes, and Soil Stripes in the Wind River Mountains, Wyoming, Geol. J., 57, 143–153, 1949. a
Seleshi, Y. and Zanke, U.: Recent Changes in Rainfall and Rainy Days in
Ethiopia, Int. J. Climatol., 24, 973–983, https://doi.org/10.1002/joc.1052, 2004. a
Steinemann, O., Reitner, J. M., Ivy-Ochs, S., Christl, M., and Synal, H.-A.:
Tracking rockglacier evolution in the Eastern Alps from the Lateglacial to
the early Holocene, Quaternary Sci. Rev., 241, 1–19,
https://doi.org/10.1016/j.quascirev.2020.106424, 2020. a
Tierney, J. E., Russell, J. M., Huang, Y., Damsté, J. S. S., Hopmans, E. C., and Cohen, A. S.: Northern Hemisphere Controls on Tropical Southeast African Climate During the Past 60,000 Years, Science, 322, 252–255, https://doi.org/10.1038/nature02251, 2008. a
Tierney, J. E., Russell, J. M., Sinninghe Damsté, J. S., Huang, Y., and
Verschuren, D.: Late Quaternary Behavior of the East African Monsoon and the Importance of the Congo Air Boundary, Quaternary Sci. Rev., 30, 798–807, https://doi.org/10.1016/j.quascirev.2011.01.017, 2011.
a
Umer, M., Kebede, S., and Osmaston, H. A.: Quaternary Glacial Activity on the
Ethiopian Mountains, in: Developments in Quaternary Sciences, vol. 2
of Quaternary Glaciations – Extent and Chronology, Part IIII, 1st Edn., edited by: Ehlers, J. and Gibbard, P., Elsevier, Amsterdam, 171–174, https://doi.org/10.1016/S1571-0866(04)80122-2, 2004. a
Vieira, G., Mora, C., and Faleh, A.: New Observations Indicate the Possible
Presence of Permafrost in North Africa (Djebel Toubkal, High Atlas, Morocco), The Cryosphere, 11, 1691–1705, https://doi.org/10.5194/tc-11-1691-2017, 2017. a
Viste, E. and Sorteberg, A.: Moisture Transport into the Ethiopian Highlands, Int. J. Climatol., 33, 249–263, https://doi.org/10.1002/joc.3409, 2013. a
Vockenhuber, C., Miltenberger, K.-U., and Synal, H.-A.: 36Cl Measurements with a Gas-Filled Magnet at 6 MV, Nucl. Instrum. Meth. B, 455, 190–194, https://doi.org/10.1016/j.nimb.2018.12.046, 2019. a
Washburn, A.: Permafrost Features as Evidence of Climatic Change, Earth-Sci.
Rev., 15, 327–402, https://doi.org/10.1016/0012-8252(80)90114-2, 1980. a, b
Wicky, J. and Hauck, C.: Air Convection in the Active Layer of Rock Glaciers, Front. Earth Sci., 8, 1–17, https://doi.org/10.3389/feart.2020.00335, 2020. a
Williams, F.: Safeguarding Geoheritage in Ethiopia: Challenges Faced and the Role of Geotourism, Geoheritage, 12, 1–22,
https://doi.org/10.1007/s12371-020-00436-9, 2020. a
Wilson, P., Bentley, M. J., Schnabel, C., Clark, R., and Xu, S.: Stone Run
(Block Stream) Formation in the Falkland Islands over Several Cold Stages, Deduced from Cosmogenic Isotope (10Be and 26Al) Surface Exposure Dating, J. Quaternary Sci., 23, 461–473, https://doi.org/10.1002/jqs.1156,
2008. a
Wöllauer, S., Zeuss, D., Hänsel, F., and Nauss, T.: TubeDB: An
on-demand processing database system for climate station data, Comput. Geosci., 146, 2–10, https://doi.org/10.1016/j.cageo.2020.104641, 2020. a
Short summary
Large sorted stone stripes have been discovered on the 4000 m high central Sanetti Plateau of the tropical Bale Mountains in Ethiopia. The stripes are a mystery as similar landforms have so far only been reported in the temperate zone and polar regions. Our investigations suggest that the stripes formed in the vicinity of a former ice cap on the plateau during a much colder climatic period. The distinct pattern is the result of a process related to cyclic freezing and thawing of the ground.
Large sorted stone stripes have been discovered on the 4000 m high central Sanetti Plateau of...