Acoustic velocity measurements for detecting the crystal orientation fabrics of a temperate ice core

Abstract. The crystal orientation fabric (COF) in ice cores provides detailed information, such as grain size and distribution the of crystals relation to large-scale glacier flow. These data are relevant for a profound understanding dynamics deformation history glaciers sheets. intrinsic, mechanical anisotropy causes an polycrystalline affects velocity acoustic waves propagating through ice. Here, we employ obtain seismic core samples compare results with calculated velocities derived from COF analyses. originate Rhonegletscher (Rhone Glacier), temperate Swiss Alps. Point-contact transducers transmit ultrasonic P dominant frequency 1 MHz into measure variations travel times these set azimuthal angles. In addition, elasticity tensor is obtained laboratory-measured COF, calculate associated velocities. We COF-derived profiles measured profiles. Especially presence large grains, two methods show significantly different since measurements examine limited volume core, whereas integrated over larger parts core. This discrepancy between decreases increasing number grains that available within sampling volume, both provide consistent similar amount grains. also explore limitations suggestions improving their results. could be employed continuously along cores. They suitable support analyses by bridging gaps discrete can acquired minutes do not require extensive preparation when using point-contact transducers.