The destruction of rocky shores at high latitudes according to precision measurements data

3rd National scientific conference with foreign participants "Geodynamical Processes and Natural Hazards"

生态环境科学

Afanas'ev, V.V.^1 ; Uba, A.V.^1

Institute of Marine Geology and Geophysics Far Eastern Branch of Russian Academy of Science, Nauki st. 1B, Yuzhno-Sakhalinsk

693022, Russia^1

关键词: Air temperature;    Coastal cliff;    Destruction rates;    High Latitudes;    High-precision;    Precision measurement;    Quantitative parameters;    Wavebreaking;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/324/1/012025/pdf
DOI  :  10.1088/1755-1315/324/1/012025

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

New high-precision data on the surface destruction rates of a co-seismically raised bench as a result of the Nevelsk earthquake in August 2, 2007, Mw = 6.2 in Nevelsk allowed to determine that the destruction of subvertical coastal cliffs occurs with the speeds nearly an order of magnitude larger, than the speed destruction of subhorizontal bench surfaces. The role of wave influence in the benches formation is mainly reduced to the mobilization and removal of debris obtained as a result of frost weathering at negative air temperatures. High-precision orthophotos and 3D models of high coastal ledge composed of volcanogenic-sedimentary rocks made it possible to identify the cliffs destruction mechanisms with non-uniform strength and to determine their quantitative parameters. It was found that the destruction occurs along structurally weakened zones, as well as during the collapse of large rocks blocks due to the formation of wave-breaking holes in rapidly destructing tuffs. Suffosion in tuffs and their contacts significantly weakens the solid characteristics of volcanogenic-sedimentary mountain massives. The retreat of the coastal scarp brow formed by volcanogenic-sedimentary rocks can reach several meters per year under these conditions.