深しん海かい平へい原げん

noun

abyssal plain

Oceanographic term for a flat or gently sloping area of the deep ocean floor, typically at depths of 2,200–5,500 meters.

• 深しん海かい平へい原げんは、大たい陸りく棚だなの外そと側がわに広ひろがる平へい坦たんな海かい底てい地ち形けいである。

  Abyssal plains are flat seafloor features that extend beyond the continental shelf.