Open AccessStructure and composition of a tidewater glacier push moraine, Svalbard, revealed by DC resistivity profiling
Author(s) -
KRISTENSEN LENE,
JULIUSSEN HÅVARD,
CHRISTIANSEN HANNE H.,
HUMLUM OLE
Publication year - 2009
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.2008.00045.x
Subject(s) - geology , moraine , glacier , geomorphology , borehole , rock glacier , permafrost , tidewater glacier cycle , terminal moraine , tidewater , glacier terminus , landform , ground penetrating radar , ice stream , paleontology , oceanography , radar , ice calving , sea ice , cryosphere , pregnancy , lactation , biology , genetics , telecommunications , computer science
A push moraine deposited by the surging tidewater glacier Paulabreen (Svalbard) was investigated using 2D resistivity profiling. Six longitudinal and transverse profiles were obtained on the moraine and the resistivities were compared with data from three boreholes. Four profiles indicate that the inner part of the moraine is ice‐cored and that the buried glacier ice is more than 30 m thick. A transverse profile shows evidence of basal crevasses near the former glacier margin. Three profiles cross the former glacier margin and onto a proglacial plain which dips slightly away from the former glacier margin. Low resistivities were encountered where borehole and field observations indicate that the plain consists of marine muds with a high salt content. This landform has previously been interpreted as a slab of seabed pushed up in front of the surging glacier, possibly facilitated by permafrost in the seabed. We suggest, alternatively, that the landform originated from sediments extruded from below (or pushed in front of) the glacier at the surge terminus and deposited as a debrisflow. Ground penetrating radar can reveal small‐scale structures, but larger structures and overall composition are better imaged by resistivity measurements.