Thermistors and Inclinometers

Borehole strings with inclinometers and thermistors are being constructed at UCSC. They will be frozen into the narrow 10cm boreholes across the grounding zone sites. Data are telemetered to the surface and will be used in combination with continuously recording GPS receivers (supplied by UNAVCO) to determine ice strain rates.

 

The combined approach of data from inclinometer/thermistor strings and GPS units constrains strain rates due to both horizontal and vertical pure shear and vertical simple shear as ice goes afloat. These measurements permit quantification of relevant terms in the 3D stress tensor by using measured strain rates and ice flow law with the ice viscosity parameter estimated from our vertical ice temperature determinations.

Strain measurements are at the core of the glaciological component of RAGES, and hence are important to obtain. The inclinometer/thermistor strings will be deployed at the end of operations at the RAGES field sites. The GPS units and the strings will be left out as long-term observatories for a year after deployment. The strings are disposable if environmentally agreeable; the GPS units will need collection.