Explorer-in-training Adrianna Ebrahim works with NOAA Ocean Exploration expedition coordinator team lead Shannon Hoy to launch the expendable bathythermographs, or XBTs, during the Seascape Alaska 6 expedition. XBTs are small torpedo-shaped probes used to measure temperature throughout the water column, generating a temperature profile. Scientists then use software that combines temperature profiles from an XBT with surface salinity data to determine an overall sound speed profile. The sound speed values can then be applied to multibeam soundings in real time for an accurate measure of bathymetry.