Description: Escarpments are “elongated, characteristically linear, steep slopes separating horizontal or gently sloping sectors of the sea floor in non-shelf areas."
Description: Submarine canyons are defined as “steep-walled, sinuous valleys with V-shaped cross sections, axes sloping outward as continuously as river-cut land canyons and relief comparable to even the largest of land canyons.”
Description: A seamount is “a discrete (or group of) large isolated elevation(s), greater than 1,000 meters in relief above the sea floor, characteristically of conical form.”
Description: This layer shows valleys on the continental shelf. Valleys shown are greater than 10 kilometers in length and 10 meters in depth overall and have an elongated shape roughly four times greater in length than width.
Description: A ridge is “an isolated (or group of) elongated narrow elevation(s) of varying complexity having steep sides, often separating basin features” and greater than 1,000 meters in relief.
Description: Spreading ridges are mountainous chains of seafloor built by volcanic activity along tectonic plate boundaries which are moving away from each other.
Description: Fans are “a relatively smooth, fan-like, depositional feature normally sloping away from the outer termination of a canyon or canyon system.”
Description: Continental rises occur between the continental slopes and the deep ocean floor (abyssal plain). They are areas of sediments settled in a gentle slope rather than the steeper angle of the continental slope.
Description: Terraces are “isolated (or groups of) relatively flat horizontal or gently inclined surfaces, sometimes long and narrow, which are bounded by a steeper ascending slope on one side and by a steeper descending slope on the opposite side.”
Description: A trench is “a long narrow, characteristically very deep and asymmetrical depression of the sea floor, with relatively steep sides.” Trenches are generally distinguished from troughs by their “V” shape in cross section.
Description: These layers show classifications of abyssal and shelf areas of the seafloor. The abyssal classification based on topography is divided into plains, hills, or mountains. The shelf classification based on vertical relief is divided into areas of high, medium, and low relief.
Description: The abyss is the area of seafloor located at depths below the foot of the continental slope and above the depth of the hadal zone (defined as deeper than 6,000 meters). This layer was classified into areas of plains, hills and mountains based on variation in topography.
Description: The continental shelf is “a zone adjacent to a continent (or around an island) and extending from the low water line to a depth at which there is usually a marked increase of slope towards oceanic depths”. A classification of the continental shelf based on vertical relief yielded three classes: Low-relief shelf; Medium-relief shelf; and High-relief shelf.
Description: The abyss is the area of seafloor located at depths below the foot of the continental slope and above the depth of the hadal zone (defined as deeper than 6,000 meters).
Description: The continental shelf is "a zone adjacent to a continent (or around an island) and extending from the low water line to a depth at which there is usually a marked increase of slope towards oceanic depths."
Description: The slope is “the deepening sea floor out from the shelf edge to the upper limit of the continental rise, or the point where there is a general decrease in steepness.”