XBT

The Expendable Bathythermograph (XBT) has been used by oceanographers for many years to obtain information on the temperature structure of the ocean to depths of up to 2000 meters. The use of XBT's to measure the ocean's subsurface has significantly increased over the past decade. For the PRISM cruise, so far, we have fired a dozen of them to identify the modified circumpolar deep water (MCDW). The following picture shows one deployment of the XBT.

Marco Pedulli firing an XBT near the Ross Bank, Antarctica