Back in January of this year, Bob Dziak, Bill Hanshumaker and I were out in the field for the deployment of a new mooring, the FODH (Full Ocean Depth Hydrophone). The FODH is a newly designed system for collecting acoustic recordings in the deepest depths of the oceans. NOAA’s Ocean Exploration Program ( funded this project nearly a year ago and in January of this year, after months of planning and coordination, we were finally able to deploy the gear in an effort to reach the deepest place in the world’s oceans,  Challenger Deep in the Marianas Trench southwest of Guam . The engineers at NOAA-PMEL worked for several months designing, building and testing the specialized mooring for a slow, controlled descent to the seafloor, allowing the equipment to equilibrate slowly to the extremely high pressures and avoid being crushed at nearly 11 km depth. Our chief acoustics engineer, Haru Matsumoto, designed a specialized titanium pressure housing and sound acquisition system unique for this deep ocean application and technician Alex Turpin assembled and tested the instrumentation.

FODH mooring on deck of USCGS Sequoia
FODH mooring on deck of USCGS Sequoia (R. Dziak)
Map showing the location of Challenger Deep in the western Pacific Ocean


Back to January of this year…, we flew to Guam to join the U.S. Coast Guard buoy tender Sequoia and sail out 200 miles to Challenger Deep in the Marianas Trench to deploy the FODH on its first science mission. It was exciting with some initial heavy weather (running into a typhoon!), but we eventually had a successful deployment and got the gear to the seafloor. The Coast Guard coverage of the deployment mission can be found here USCGChallengerDeep .

heavy seas and winds on the way to Challenger Deep
Heavy seas and strong winds on the way out to Challenger Deep (R. Dziak)
12,000 m rated glass floats being deployed off the ship (R. Dziak)
12,000 m rated glass floats being deployed off the ship (R. Dziak)

I’m going to keep this post brief. I just wanted to give some preliminary background on the project with a few pictures; there will be a lot more detailed information (including video footage) of our deployment and recovery expeditions to follow. We are heading back out to Challenger Deep next week, so stay tuned for updates. Also, for more information and some cool history and images of this unique spot on earth check out James Cameron’s website (

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One thought on “Mission to Challenger Deep

  1. This is so inspiring! I am a teacher, I like it when my students want to know more about the oceans. Works like in this page open our eyes to the new worlds and future. Thank you so much.


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