GROUND PENETRATING RADAR OF ARCTIC POLYGONAL WEDGE STRUCTURES
D.E. Edemsky1, V.E. Tumskoy2, I.V. Prokopovich1
1Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia
2Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Yakutsk, Russia
Keywords: Polygonal microrelief, polygonal wedge structures, ground penetrating radar, ground penetrating radar probing, Taimyr Peninsula, Kotelny Island
Abstract
Ground penetrating radar method which was applied to study distribution and occurrence of polygonal wedge ice along with other structural features in the near-surface layers of the permafrost section on the western coast of the Taymyr Peninsula and Kotelny Island. The polygonal microrelief in the region under study is at a descending stage of development and is mainly placed in sand-gravel deposits and silts with rare interlayers of light gray sands. The ground penetrating radar (GPR) data were analyzed and interpreted by modeling of the polygonal wedge ice structures in gprMax - a software that simulates electromagnetic wave propagation. The effect of the seasonally thawed layer on the measurement results was assessed, and the results of ground penetrating radar sounding of the polygonal microrelief were interpreted. The ground penetrating radar studies performed in this work indicate that unmelted lower ends of ice wedges preserved under pseudomorphs can be observed in some spots. Repeated wedge structures of higher generation, which do not appear on the surface, have been identified. The propagation velocity of electromagnetic waves in the studied sediments was determined.
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