Slow Mass Movement on a Subalpine Slope of Mount Halla, Jeju Island Taeho Kim* 1 710m 2 58 2cm 0 24cm 0 3cm 0 05cm Abstract In order to investigate the rates and factors of slow mass movement on a subalpine slope of Mount Halla, two painted stone lines were monitored in a bare patch at 1,710 m a.s.l. The mean movement of surface gravels is 58.2 cm, equivalent to 0.24 cm/day. However, the rates of movement vary with seasons. Compared with 0.05 cm/day of a non-frozen season, a frozen season shows 0.3 cm/day. It implies that the movement of surface gravels could be largely controlled by periglacial processes during a frozen season. In particular, frost creep including needle ice creep plays a main role in the movement of gravels under the thermal and soil conditions which are favorable for needle ice development. Since line II is located at a steeper slope than line I, the movement of line II was always larger than that of line I. However, slope gradient is not the most dominant factor contributing the movement of gravels, which can be interrupted by downslope big gravels and vegetation patches. The size and specific weight of gravels also can influence the movement of gravels. Porous and light scoriae result in relatively quick movement of gravels on the subalpine slope of Mount Halla. : slow mass movement, frost creep, needle ice, subalpine zone, Mount Halla 2008 2009 (Professor, Department of Geography Education, Jeju National University), kimtaeho@jejunu.ac.kr 375
(Shoma et al., 1979; Suzuki, 1992) (King, 1971; Grab, 2002; Kim, 2008) (Jang, 1983; Park, 2000; Kim, 2001) (Lee, 1991; Kwon, 1992; Kee, 1999) (Kwon, 1999) (Kwon, 1987) Bt (Park, 1987; Oh, 1989; Kee, 1999) (Sin et al., 2004) (Choi, 1988 (Oh, 2006) (Kwon, 1999) Bt (Kee, 1999; Oh, 2006) 1 400m 1 600m 1 800m (Kim, 2006) 1 710m 1 600m (Figure 1) (Jeju Provincial Government, 2000) 7 (Tamanyu, 1990) 1 672m 2006 6 4 10 7 2 8 2006 3 991 5mm 5 6 869 5mm 860 5mm 7 685 5mm 12 3 100mm 376
Figure 1. Distribution of the subalpine grassland (shade) of Mount Halla and the experimental bare patch in a northwestern gentle slope. (Jeju Regional Meteorological Office, 2007) (Yim et al., 1991) (Figure 1) (Kim and Kim, 1985) 1 710m (Figure 1) 7 6 26 12m 30 80cm (Figure 2) 60cm 250cm 5cm 40cm 10cm 2006 11 3 377
Figure 2. Two painted stone lines on surface gravels in the experimental bare patch. 2006 12 1012 272007 4 25 7 6 11 7 31 12 27 7 31 10cm (7.5YR 2/2) (7.5YR 3/4) HOBO (H08-008-4) (TMC6) 50cm 1cm (Figure 2) 2006 10 2 2007 3 27 970m Figure 3 Table 1 11 3 12 10 15 9cm 12 10 4 2 14 3cm 4 2 5 7 9 5cm 5 7 6 11 1 6cm 6 11 7 31 1 3cm 11 3 12 10 24 6cm 12 10 27 8 1cm 12 27 4 2 18 8cm 4 2 5 7 20 2cm 5 7 6 11 2 0cm 42 6cm 73 7cm 0 16cm 0 34cm 378
Figure 3. Displacement of two painted stone lines. Table 1. Mean movement of two painted stone lines. Date Line Line 06. 12. 10 15.9 24.6 06. 12. 27-8.1 39.7(0.21) 07. 4. 2 14.3 18.8 07. 5. 7 9.5 20.2 07. 6. 11 1.6 2.0 2.9(0.03) 07. 7. 31 1.3 - Total 42.6(0.16) 73.7(0.34) 71.7(0.39) 2.0(0.06) Notes: Unit is cm, and figures in brackets indicate a mean daily movement of surface gravels. 11 3 5 7 39 7cm 71 7cm 185 0 21cm 0 39cm 5 7 7 31 85 2 9cm 6 11 2 0cm 0 03cm 0 06cm 11 3 12 10 4 2 5 7 15 9cm 24 6cm 20 3cm 9 5cm 20 2cm14 9cm 37 35 0 55cm 0 42cm 1 3 23 5 53 3cm 35 0 104 0cm 5 3 10cm 3 9 6 6 8 1 5 1 10 2 Figure 4 0 67 379
Figure 4. Relationship between mean movement of gravels and slope gradient. 50cm 10 27 22 0 61 11 7 0 1 46 11 0 8 12 10 4 2 01 26 26 0 1 2 0 2 6 3 3 3 0 4 22 (Figure 5) 12 28 11 07 12 30 4 14 1 Figure 5. Air temperature of the experimental bare patch. 380
Figure 6. Freezing and thawing condition in the experimental site during a measured period. 1 (Kim, 2008) 1m 1 2 12 1 2 1 28 4 11 1 3 3 6 10 72 10 27 0 5 11 19 12 9 1 3 1 4 2 17 45 2 18 3 27 38 20 17 3 26 0 3 28 0 58 /100m(Kong, 1999) 1 710m 3 14 18 4 26 75 2 84 1 5 4 11 19 18 (Figure 6) (Figure 2) 1 5 15 5cm 5 7cm 1 0 10 5cm 3 5cm 2 3 (Figure 7) 381
Figure 7. Number of gravels based on the lithology and diameter. Figure 8. Distribution of particle size of dark brown soil in the experimental bare patch. 74 2 73 3 75 0 (Figure 7) 1 17 31 25 0 2 4 33 8 4 8 46 6 8 10 7 2 (Figure 8) 4 5 20 2 1 400m 68 382
(Suzuki, 1992) (Kim, 2006) 2007 6 11 7 31 5cm 4 5cm 180cm 240cm 5 7 6 11 8cm 130cm (Figure 3) (Figure 3) 0 3cm 0 05cm (Washburn, 1980) (frost creep) (needle ice creep) (Ono, 1978) Figure 9 (Shoma et al., 1979) 1 5m (Koaze, 1983) 1 3 (Koaze, 1983) 75 4 11 19 18 383
Figure 9. Partial thaw of needle ice makes a gravel to fall and tilt downslope. 46 6 (segregated ice) (French, 1996) 1 3 (Table 1) Sawaguchi and Koaze(1998) C SC D SC(Ono, 1983; Horii et al., 1987) C (Higashi, 1981; Ono, 1982) (Sawaguchi and Koaze, 1992) SC C D (Higashi and Corte, 1971; Koaze, 1983) 5 3 8 1 1 8 384
Figure 10. The movement of gravels gets faster with an increase of gravel size. The measuring tape indicates the original position of Line. (Figure 4) 0 67 23 5 53 3cm 35 0 104 0cm (Figure 2) 3 5cm 5 7cm (Figure 10) 16 8cm 2007 6 11 35 0cm 23 5cm 120cm 17cm (cobble) 34 0cm 230cm 29cm (boulder) 35 5cm 40cm 29cm (Figure 11) 80cm 150 160cm (Figure 11) Koaze(1983) 385
Figure 11. The downslope movement of gravels is interrupted by big gravels and vegetation patches. The measuring tape indicates the original position of Line. 74 1 31 1 9 1 7 2 6 2 7 1 86 2 12 2 04 (Lee et al., 2007) 1 710m 2 1 2006 11 3 2007 7 31 23 5 53 3cm 35 0 104 0cm 386
58 2cm 0 24cm 0 3cm 0 05cm 2 0 55cm 0 42cm 1 3 3 Choi, S. G., 1988, Fossil cryogenic structures in the terrace deposit of Oship River, Samchok, Korea, Science Reports of the Tohoku University, 7th series(geography), 38, 133-139. French, H. M., 1996, The Periglacial Environment (2nd edition), Longman, London. Grab, S. W., 2002, Turf exfoliation in the High Drakensberg, southern Africa, Geografiska Annaler, 84A, 39-50. Higashi, A., 1981, Elements of Cold Region Engineering, Kokonshoin, Tokyo 1981 Higashi, A. and Corte, A. E., 1971, Solifluction: A model experiment, Science, 171, 480-482. Horii, T., Matsuoka, N., and Matsukura, Y., 1987, Experimental study on soil movement due to frost creep, Bulletin of Environmental Research Center, The University of Tsukuba, 11, 21-27 (in Japanese). Jang, H., 1983, Periglacial landforms in the eastern part of the main ridge of Mt. Jiri, South Korea, Geography, 27, 31-50 (in Korean). Jeju Provincial Government, 2000, Geologic Report of the Segwipo-Hahyori Sheet, Korea Institute of Geology, Mining and Materials, Daejeon 2000 Jeju Regional Meteorological Office, 2007, The Detailed Climatic Characteristics of Automated Weather Stations in Jeju Island, Jeju Regional Meteorological Office, Jeju 2007 AWS Kee, K. D., 1999, Morpho-pedologic Milieu in Taegwallyong Area, Ph.D. Dissertation, Korea 387
National University of Education (in Korean). Kim, C. and Kim, M., 1985, Phytosociological study of grassland and scrub on subalpine zone in Mt. Halla, Report of Survey and Study of Mt. Halla, 311-330 (in Korean). Kim, T., 2001, Earth hummocks on the crater floor of Baegnokdam at Mt. Halla, Journal of the Korean Geographical Society, 36, 233-246 (in Korean). Kim, T., 2006, Rates and processes of bare patch denudation in the subalpine grassland of Mt. Halla, Journal of the Korean Geographical Society, 41, 657-669 (in Korean). Kim, T., 2008, Thufur and turf exfoliation in the subalpine grassland of Mt Halla in Jeju Island, Korea, Mountain Research and Development, 28, 272-278. King, R. B., 1971, Vegetation destruction in the subalpine and alpine zones of the Cairngorm Mountains, Scottish Geographical Magazine, 87, 103-115. Koaze, T., 1983, Slow mass movement in periglacial regions, Transactions Japanese Geomorphological Union, 4, 189-203 (in Japanese). Kong, W. S., 1999, The vertical distribution of air temperature and thermal amplitude of alpine plants on Mt. Halla, Cheju Island, Korea, Journal of the Korean Geographical Society, 34, 385-394 (in Korean). Kwon, H. J., 1999, Geomorphology (4th eds), Bobmunsa, Seoul (, 1999, 4,, ). Kwon, S. S., 1987, A study on late Quaternary periglacial cryogenic structures of granite regolith in Korea, Journal of Geography (Jirihak Nonchong), Supplement 4, 1-120 (in Korean). Kwon, S. S., 1992, Nivation morphology at Heul-Ri in Kwangwon Province, Korea, Journal of Geography (Jirihak Nonchong), 19, 1-10 (in Korean). Lee C., Cho, T., Lee, S., and Won, K., 2007, A study of weathering characteristic of Baeknokdam trachyte in Jeju Island, The Journal of Engineering Geology, 17, 235-251 (in Korean). Lee, Y. B., 1991, The Study of Nivation Hollows in Daekwan-Ryoung Area, Master Thesis, Korea National University of Education (in Korean). Oh, K. S., 1989, Origin of Bt bands in sandy deposits, The Korean Journal of Quaternary Research, 3, 35-45 (in Korean). Oh, K. S., 2006, Cryogenic structures in superficial formation and associated periglacial morphoclimatic milieu in Korean Peninsula, Journal of the Geomorphological Association of Korea, 13, 1-17 (in Korean). Ono, Y., 1978, Pipkrakes as a periglacial process, Bulletin of Environmental Research Center, The University of Tsukuba, 2, 47-55 (in Japanese). Ono, Y., 1983, Soil erosion by pipkrakes on Tsukuba Upland, Tsukuba Environmental Studies, 7, 128-140 (in Japanese). Park, K, 1987, Study of Dune-Reddening at Cheonripo, Master Thesis, Seoul National University (in Korean). Park, K., 2000, Mountaintop block fields of the Seoraksan National Park in Kwangwon Province, Korea, Journal of the Korean Geographical Society, 35, 653-663. Sawaguchi, I. and Koaze, T., 1998, Field experiment on periglacial mass movement and frost heave in the Kitakami mountains, northwestern Japan, Transactions Japanese Geomorphological Union, 19, 221-242 (in Japanese). Shoma, H., Okazawa, S., and Iwata, S., 1979, Slow massmovement processes in an apline region of Mt. Shirouma Dake, the Japan Alps, Geographical Review of Japan, 52, 562-579 (in Japanese). Sin, J., Yu, K, Naruse, T., and Hayashida, A., 2004, Study on loess-paleosol stratigraphy of Quaternary unconsolidated sediments at E55S20-IV pit of Chongokni Paleolithic site, Journal of the Geological Society of Korea, 40, 369-381 (in Korean). Suzuki, I., 1992, Movements of surface gravels on bare 388
ground in the Tanigawa Mountains, central Japan, showing the relationship between periglacial and non-periglacial processes, Geographical Review of Japan, 65A, 75-91 (in Japanese). Tamanyu, S., 1990, The K-Ar ages and their stratigraphic interpretation of the Cheju Island volcanics, Korea, Bulletin of the Geological Survey of Japan, 41, 527-537 (in Japanese). Washburn, A. L., 1980, Geocryology: A Survey of Periglacial Processes and Environments, John Wiley, New York. Yim, Y., Paik, K., and Yi, N., 1991, The Vegetation of Mt. Halla, Chungang University Press, Seoul 1991 690-756 66 kimtaeho @jejunu.ac.kr, 064-754-3235) Correspondence: Taeho Kim, Department of Geography Education, Jeju National University, Jejudaehak-Road, Jeju, 690-756, Korea (e-mail: kimtaeho@jejunu.ac.kr, phone: +82-64-754-3235) 389