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The relationship between frost heave and downslope soil movement: field measurements in the Japanese Alps
Author(s) -
Matsuoka Norikazu
Publication year - 1998
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/(sici)1099-1530(199804/06)9:2<121::aid-ppp281>3.0.co;2-c
Subject(s) - geology , frost heaving , debris , frost weathering , creep , geotechnical engineering , geomorphology , frost (temperature) , soil science , soil water , oceanography , materials science , composite material
This paper presents three years of data on soil movement on two alpine slopes. Automatic instrumentation provided data on ground surface heaving and downslope subsurface debris displacements. Manual measurements of painted lines indicated downslope surface debris displacements. Observations highlight the role of diurnal frost heaving in soil movements. Frost heave of up to 3 cm takes place 30 to 70 times per year, reflecting both needle ice growth and/or near‐surface ice lens formation. The frost heave activity is accompanied by downslope displacements of the uppermost 20 cm of soil. The surface debris moves downslope at a velocity of about 50 cm a −1 on the 30° slope and about 5 cm a −1 on the 14° slope. The potential frost creep predicted by the cumulative heave amount considerably underestimates the surface velocity on the 30° slope, and slightly overestimates it on the 14° slope. The surface velocity on both slopes is nearly proportional to the second power of the slope gradient. These conditions demonstrate that steeper slopes are dominated by the rolling of surface debris resulting from the downslope bending of ice needles. Velocity profiles are discontinuous below the surface debris, probably reflecting the differential movement by needle ice creep and frost creep. © 1998 John Wiley & Sons, Ltd.