Strain meter measurements of sea ice under the influence of a moving load from the sea ice runway near McMurdo Station

Using a strain meter, with a 500 mm gauge length, the influence of a moving load on the strain produced in sea ice was measured firstly by driving a vehicle (ford pickup) on the sea ice runway near McMurdo Station, with the vehicle being driven at speeds up to 70 mph and secondly from an aircraft during taxiing, taking off and landing on the sea ice runway. The vehicle was used in the first season and calculations of the maximum aircraft landing and takeoff weights the sea ice could support were calculated. In the following season, new strain meters that could be buried in the ice were used. When a vehicle moves over floating sea ice, a flexural or bending wave is produced in front of the vehicle while a gravity wave follows the vehicle. After the strain meters were checked for a moving vehicle (truck), three strain meters placed at the 2000, 3000 and 4000 ft marks from the northern end of the sea ice runway were used to measure the strain produced by a Hercules (C130) and Starlifter (C141) aircraft taxiing, taking off and landing. To obtain the size of the wavelength of waves produced at high speeds a Hercules was flown along the length of the runway at an altitude of approximately 25 ft and speeds of 100, 130 and 160 knots. Further information on the shape of the waves was obtained by the Hercules flying at right angles to the runway.