Exploring the Deep Ocean: Digital Mermaids and Sea Serpents
David Sandwell smiling at the camera

Dr. David Sandwell
Professor – University of Southern California and Scripps Institute of Oceanography
Institute of Geophysics and Planetary Sciences

Wednesday, March 1, 2023
1 pm – CSL 422
watch Dave’s talk

Abstract
Medieval nautical maps have mermaids and sea serpents to fill the voids in uncharted areas and illustrated the wonders and dangers of the deep ocean.   Today less than 25% of the deep ocean has been charted by ships.  There are many areas in the Southern Ocean with data gaps of 10 to 100 km and most of these areas will not be surveyed in our lifetimes.  This study is focused on the development of synthetic bathymetry to fill the gaps with realistic small-scale texture consisting of abyssal hills (mermaids) and 40,000 small seamounts (serpents) detected by satellite altimetry. Such texture is important in many physical oceanographic modeling efforts as well as for planning shipboard surveys. (The global depth grid at 15 arcsecond is available at the following site http://topex.ucsd.edu/pub/synbath/)

Damage to USS San Francisco, a Los Angeles class nuclear submarine, following a crash into an uncharted seamount in January 2005. The crash occurred at a depth of ~150 m while the submarine was traveling a speed of 30 knots. US Navy charts had a depth of more than 2000 m at the crash site.
Damage to USS San Francisco, a Los Angeles class nuclear submarine, following a crash into an uncharted seamount in January 2005. The crash occurred at a depth of ~150 m while the submarine was traveling a speed of 30 knots.  US Navy charts had a depth of more than 2000 m at the crash site.  In October, 2021 the nuclear attack submarine USS Connecticut crashed into an uncharted seamount during maneuvers in the South China Sea. Both incidents were partly blamed on inaccurate nautical charts.