Instruments and Methods Using distributed temperature sensors to monitor an Antarctic ice shelf and sub-ice-shelf cavity

• Main Author: S. W. Tyler
• Format: Dataset
• Language: unknown
• Subjects: fiber optic; CTEMPs; Ross Ice Shelf; McMurdo; ice shelf; Windlass Bight; DTS; Antarctic; McMurdo Ice Shelf; Windless Bight; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://search.dataone.org/view/sha256:849a836ddba4448e93d3cc5fc43b8470baad978adfc64204cf08fd6101942478

Monitoring of ice-shelf and sub-ice-shelf ocean temperatures represents an important component in understanding ice-sheet stability. Continuous monitoring is challenging due to difficult surface access, difficulties in penetrating the ice shelf, and the need for long-term operation of nonrecoverable sensors. We aim to develop rapid lightweight drilling and near-continuous fiber-optic temperature-monitoring methods to meet these challenges. During November 2011, two instrumented moorings were installed within and below the McMurdo Ice Shelf (a sub-region of the Ross Ice Shelf, Antarctica) at Windless Bight. We used a combination of ice coring for the upper portion of each shelf borehole and hot-point drilling for penetration into the ocean. The boreholes provided temporary access to the ice-shelf cavity, into which distributed temperature sensing (DTS) fiber-optic cables and conventional pressure/temperature transducers were installed. The DTS moorings provided nearcontinuous (in time and depth) observations of ice and ocean temperatures to a depth of almost 800 m beneath the ice-shelf surface. Data received document the presence of near-freezing water throughout the cavity from November through January, followed by an influx of warmer water reaching 150 m beneath the ice-shelf base during February and March. The observations demonstrate prospects for achieving much higher spatial sampling of temperature than more conventional oceanographic moorings. Raw project data is available by contacting [e-mail]