On the frontal dynamics and morphology of submarine debris flows

被引:78
作者
Ilstad, T
De Blasio, FV
Elverhoi, A
Harbitz, CB
Engvik, L
Longva, O
Marr, JG
机构
[1] Univ Oslo, Dept Geosci, Int Ctr Geohazards, N-0316 Oslo, Norway
[2] Norwegian Geotech Inst, Int Ctr Geohazards, N-0806 Oslo, Norway
[3] Sor Tronderlag Univ Coll, Dept Technol, N-7004 Trondheim, Norway
[4] Geol Survey Norway, Int Ctr Geohazards, N-7491 Trondheim, Norway
[5] Univ Minnesota, St Anthony Falls Lab, Minneapolis, MN 55414 USA
关键词
submarine slide; debris flow; morphology; outrunner blocks; experiment;
D O I
10.1016/j.margeo.2004.10.020
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Several submarine debris flows show an apparently chaotic frontal part with blocks of variable size (from roughly tens to some hundreds of metres) located some distance beyond the front of the main deposits. This outrunner phenomenon was studied both in the field and in laboratory experiments. Depositional patterns in a field case (Finneidfjord, northern Norway) are classified from the outer distal part of the debris flow to the outermost outrunner block. Similar patterns were found in experimental debris flows, and we suggest that flow processes in the laboratory are applicable to the field example. Theoretical investigations are applied to assess frontal dynamics and especially the formation and motion of outrunner blocks. As the front of the debris flow pushes through ambient water, a combination of front pressure and lift force allows for intrusion of a water layer underneath the front (hydroplaning). This water layer reduces basal friction and induces tensile stresses farther behind the front, leading to a possible detachment and decoupling with respect to the main slide body. These outrunner blocks show an increased mobility compared to the main slide body and deposition of such blocks may occur far away from the main slide body. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:481 / 497
页数:17
相关论文
共 21 条
[1]  
[Anonymous], 9800051 NGI
[2]  
Booth J. S., 1993, US GEOLOGICAL SURVEY, P14
[3]   ROLE OF SUBAQUEOUS DEBRIS FLOW IN GENERATING TURBIDITY CURRENTS [J].
HAMPTON, MA .
JOURNAL OF SEDIMENTARY PETROLOGY, 1972, 42 (04) :775-793
[4]  
HAMPTON MA, 1970, THESIS STANFORD U US
[5]   Hydroplaning of subaqueous debris flows and glide blocks: Analytical solutions and discussion [J].
Harbitz, CB ;
Parker, G ;
Elverhoi, A ;
Marr, JG ;
Mohrig, D ;
Harff, PA .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2003, 108 (B7)
[6]   Laboratory studies of subaqueous debris flows by measurements of pore-fluid pressure and total stress [J].
Ilstad, T ;
Marr, JG ;
Elverhoi, A ;
Harbitz, CB .
MARINE GEOLOGY, 2004, 213 (1-4) :403-414
[7]  
JANBU N, 1996, UNPUB RASET FINNEIDF
[8]   GEOTECHNICAL ASPECTS OF A SUBMARINE SLOPE FAILURE, KITIMAT FJORD, BRITISH-COLUMBIA [J].
JOHNS, MW ;
PRIOR, DB ;
BORNHOLD, BD ;
COLEMAN, JM ;
BRYANT, WR .
MARINE GEOTECHNOLOGY, 1986, 6 (03) :243-279
[9]  
Kuijpers A, 2001, GEO-MAR LETT, V20, P149
[10]   Submarine landslides: advances and challenges [J].
Locat, J ;
Lee, HJ .
CANADIAN GEOTECHNICAL JOURNAL, 2002, 39 (01) :193-212