San Francisco State University Physics and Astronomy Department
( PSM Home |P&A Dept |SFSU )
SFSU Pacific Oceanography Project
Overview of the Pioneer Seamount Observatory
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Pioneer Seamount was the site of one of the powerful acoustic sound sources used in the ATOC experiment, designed to measure the average temperature of the Pacific Ocean to a precision of 0.005 oC. The first phase of this experiment was completed in 1997, and the sound source and underwater cable were scheduled to be removed. However, a last-minute appeal to keep the cable in place was granted. The source was disconnected, and a vertical linear array (VLA) of hydrophones replaced it. The cable is now dedicated to monitoring the underwater environment with passive acoustic devices only.

Bathymetry and Cable Location
(PMEL data, downloaded from
Detailed Bathymetry near VLA
Blowup, seen from the west

Top view showing location of VLA

(PMEL data, downloaded from