LiDAR detection of paleolandslides in the vicinity of the Suasselk盲 postglacial fault, Finnish Lapland
详细信息 查看全文
- 作者：Raimo Sutinen ; Eija Hyv枚nen ; Ilmo Kukkonen
- 关键词：LiDAR ; Landslide ; Postglacial fault ; Lapland ; Finland
- 刊名：International Journal of Applied Earth Observation and Geoinformation
- 出版年：April, 2014
- 年：2014
- 卷：27
- 期：part_PA
- 页码：91-99
- 全文大小：7397 K
文摘
Spatial distribution of paleolandslides coincides with postglacial faults (PGFs) in northern Fennoscandia, yet the timing of the seismic events and associated paleoslides is insufficiently known. We applied airborne LiDAR (Light Detection And Ranging) to record distribution of paleolandslides possibly associated with the known Suasselk盲 postglacial fault in Kittil盲, western Finnish Lapland. Landslide-buried organic material was radiocarbon dated to bring insight if the landslides were generated by single high-magnitude (Mw > 7) earthquake or if seismic activity has continued through the Holocene. We found a total of four sets of previously unrecognized paleolandslides to indicate fault-activity in the Kittil盲 area. The size of the landslide scarps exceeded up to 250-300 m in width, up to 600 m in length and 10 m in the height of the back-wall. A previously unrecognized (tentatively PGF) scarp, 6 m in height and in conjunction with paleolandslides, was found in granite rock west of the Kittil盲 village. The slide debris was similar to local tills, yet the maximum electrical conductivity (蟽a) anisotropy was incoherent to any of the ice-flow (morphological) stages recognized through LiDAR or known fabric-sedimentary stratigraphy. We found peat/gyttja beneath 6 m of slide debris which yielded radiocarbon (14C) age of 4400 卤 35 BP (cal. 5055 yr BP). Our previous finding of landslide-buried woody remnants of birch (Betula ssp.) yielded cal. 9730 yr BP in Kittil盲. These ages suggest that seismic activity has continued at least 5 ky after deglaciation.