FY 2016 Deployment and recovery of a full-ocean depth mooring at Challenger Deep, Mariana Trench Dziak, R.P., J.H, Haxel, H. Matsumoto, C. Meinig, N. Delich, J. Osse, and M. Wetzler In Oceans 2015 MTS/IEEE, Marine Technology Society and Institute of Electrical and Electronics Engineers, Washington, DC, 19–22 October 2015, doi: 10.23919/OCEANS.2015.7401902 (2015) We present the details of a unique deep-ocean instrument package and mooring that was deployed at Challenger Deep (10,984 m) in the Marianas Trench. The mooring is 45 m in length and consists of a hydrophone, RBRTM pressure and temperature loggers, nine Vitrovex® glass spheres and a mast with a satellite beacon for recovery. The mooring was deployed in January and recovered in March 2015 using the USCG Cutter Sequoia. The pressure logger recorded a maximum pressure of 10,956.8 decibars, for a depth of 10,646.1 m. To our knowledge, this is only the fourth in situ measurement of depth ever made at Challenger Deep. The hydrophone recorded for ~1 hour and stopped shortly after descending to a depth of 1,785 m (temperature of 2.4°C). The record at this depth is dominated by the sound of the Sequoia’s engines and propellers. Feature Publications | Outstanding Scientific Publications Contact Sandra Bigley | Help