Updates on Time-Space Continuous Measurement of Thermal Profiles in Frozen Media

Abstract:

Measurement of temperature, and perhaps more importantly, thermal gradient measurement represents a critical observation in permafrost and glaciated regions. In the past 5 years, application of Raman-backscatter temperature sensing along optical fibers to glaciers, ice and permafrost regions has now become both possible and practical. Distributed temperature sensing (DTS) provides spatially resolved temperatures at scales less than 50 cm, and over distances of kilometers. Temperature resolution is now commonly achievable down to 20-30 mK, with sampling frequencies of 30-60 seconds. While individual point measurements of temperature are valuable, DTS systems provide far more exciting high-resolution measurement of thermal gradients. In this work, the resolution of DTS-derived thermal gradients in ice and frozen ground are presented, along with examples of the use of DTS-derived thermal gradients to derive geothermal heat fluxes, glacial basal melt rates and time-variability in thermal gradients to infer surface boundary condition changes.