  The discovery of close-to-star gas-giant exo-planets lends support to the
idea of Earth's origin as a Jupiter-like gas-giant and to the consequences of
its compression, including whole-Earth decompression dynamics that gives rise,
without requiring mantle convection, to the myriad measurements and
observations whose descriptions are attributed to plate tectonics. I propose
here another, unanticipated consequence of whole-Earth decompression dynamics:
namely, a specific, dominant, non-erosion, underlying initiation-mechanism
precursor for submarine canyons that follows as a direct consequence of Earth's
early origin as a Jupiter-like gas-giant.
