Under Pressure: Construction and use of stress buoys in the SEDNA project Tess Mattraw1, Cathleen A. Geiger2, Jackie Richter-Menge3, Bruce C. Elder3

1Dartmouth College, Hanover, NH 2 University of Delaware, Newark, DE

3Cold Regions Research and Engineering Laboratory, Hanover, NHSN

AED

Constructing the stress buoys

Inside the stress sensor

ICESat

multi-year ice

first-year ice

Prudhoe Bay

Field Program Overview

Stress Sensor Buoy1) Argos Antenna2) Global Positioning System3) Stress Sensor4) Air Temperature5) Barometer6) Compass (inside housing)7) Data Logger (inside)8) Battery Pack (inside)

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Completed stress buoys

Stress buoys awaiting deployment

Deployed stress buoy1.Ice stress2.Three wires

magnetically plucked to record a vibration frequency

3. Steel cylinder of known strength

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Ice stress = F(cylinder strength, wire frequency, temperature)

External forces (wind, air temps)

Ice stress

Force on

cylinder wall

Cylinder deforms

Changes wire

frequency

Wire Stretches or loosens

As a WISP student working at CRREL, my responsibility to the Sea-ice Experiment Dynamic Nature of the Arctic (SEDNA) project was to construct the stress buoys that would later be deployed in the Beaufort Sea to measure the stress and movement of the sea ice. I would also help with other preparatory tasks, such as testing GPS units and other field equipment and packing for the trip.

In building the stress buoys, I came to a deeper understanding of the physics behind them. I also learned first hand about the extensive preparation involved in Arctic field research. From this I have been able to gain a greater knowledge of what goes on behind the scenes of scientific research.

Schematic layout of the field program for SEDNA