Furggwanghorn

3D Helicopter GPR surveying a rock glacier

Abstract

The primary papers from which this material is derived can be accessed [MGB+15] and [MMB+15].

Extreme heterogeneity and rugged mountainous terrains characterized by steep slopes and bouldery surfaces make rock glaciers amongst the most difficult geological features to explore using surface-based geophysical techniques. Conventional ground-penetrating radar (GPR) surveys have produced valuable subsurface information for many rock glaciers, but usually only along sparse lines because of the generally challenging to treacherous recording conditions (Fig. 397 c and d). Surface-based GPR surveys of other rock glaciers have failed to yield anything meaningful. In an attempt to provide useful subsurface information for a greater number of rock glaciers and to supply reliable images of their entire 3D structures, we conducted the first ever 3D GPR survey of a rock glacier using a helicopter mounted system. Helicopter GPR (H-GPR) has previously been employed for mapping conventional glaciers. Our results suggest that the H-GPR technique would be a practical means for exploring many other difficult to access terrains.

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Fig. 397 Frontal view of the Furggwanghorn rock glacier showing the H-GPR lines (a). Intersecting H‑GPR sections showing the trough shaped bedrock and major shear zone (b). Typical furrows and bouldery surface of the rock glacier (c) . Steep frontal slope (d).