colline abyssale

CONT: Les collines abyssales bordent [les plaines abyssales] vers le large [et] peuvent aussi bien former des îles ou des archipels au milieu de la plaine abyssale que s'insérer entre celle-ci et la base de l'escarpement continental.
OBS: colline abyssale : terme normalisé par l'Organisation hydrographique internationale en 2008.

CONT: Abyssal hills were formed as oceanic ridge. As the crust moves away from the spreading center, it cools and sinks to a lower depth. The mountainous terrain of the oceanic ridge is maintained, becoming low-lying abyssal hills at depths of more than 6,000 meters. The hills are usually covered with a blanket of unconsolidated pelagic sediments deposited with reasonable uniformity which gradually modifies and smoothes the features but do not change the original volcanic ocean floor topography that formed at the ridge.
OBS: abyssal hill: term standardized by the International Hydrographic Organization in 2008.