Borehole tilt sensor data for Jarvis Glacier, Alaska (2017-2018)

• Main Author: Ian Lee
• Format: Dataset
• Language: unknown
• Published: Arctic Data Center 2019
• Subjects: Cryosphere; Flow Dynamics; Streaming Ice; Tilt Sensors; Borehole Deformation; Ice Velocity; Jarvis Glacier; glacier; glaciers; Alaska
• Online Access: https://doi.org/10.18739/A2348GG12

Regions of streaming flow are responsible for draining the major ice sheets and alpine regions and occurs in two major groups of glaciers: polythermal and temperate. We seek to investigate the flow dynamics of streaming ice, which is characterized by weak wet-based beds that result in significant shearing as the shear margins sustain most of the driving stress. Strong shearing causes strong anisotropy to develop in the ice, the preferred orientations in the ice crystal fabric creating planes of weakness which speeds up ice flow. To measure glacier flow in streaming ice in terms of borehole deformation tilt, we developed tilt sensors to measure accelerometer and magnetometer data and deployed them in two boreholes drilled close to the shear margin of Jarvis Glacier in Alaska. Inclination, azimuth, temperature and velocity data from tilt sensors installed in the two boreholes JA and JE make up this dataset. We derived the borehole velocity profiles from inclination and azimuth, and provide the velocity data with the accompanying algorithms. The observed velocity in each borehole can be evaluated against theoretical predictions derived from Glen's exponential flow law, to tune the flow law for streaming ice.