Building Infrasound Station 55 in Windless Blight, Antarctica

During the last Antarctic summer, a team of the University of Alaska built the first infrasound station for the CTBTO Preparatory Commission in Antarctica. IS 55 is part of the International Monitoring System (IMS), which comprises a global network of 321 stations, designed to detect any form of nuclear explosion in any environment. Altogether, 13 IMS stations will be located in Antarctica. Five of them existed previously as part of scientific networks and will need significant upgrading; the remaining have to be built from scratch. Located in a harsh environment with extreme weather conditions - persistently high wind speeds, severe snow drifts and extreme seasonal temperature differences (-40 Celsius to +30 Celsius!!) - access to the stations is in many cases confined to the local summer season only (December - March).

IS 55 is using very sensitive microbarometers to detect low frequency sound waves from atmospheric explosions. For its eight sensors, set 1-3 km apart, to be able to detect an atmospheric explosion, the arrays are sited to avoid high winds. IS 55 is the only known site on earth with essentially no winds. The station is equipped with a high quality power supply unit to ensure continuous operations. Currently data is being transmitted from Antarctica on the scientific communications network to the University of Alaska. In a few months, a link will be established with the International Data Centre (IDC) in Vienna. During the installation period, the local research base staff has been trained in operating the station.

IS 55, which constitutes an important step in the build up of the IMS, is expected to be certified during the next Antarctic summer.