The continental rise is the gently sloping apron of sediment at the foot of the continental slope, where the seabed levels out towards the abyssal plain. It is built from mud and sand that flow down from the continent.
Key takeaways
- The rise sits between the steep continental slope above and the flat abyssal plain below.
- It is built from sediment carried down from the continent by turbidity currents.
- It can stretch up to about 500 km out from the foot of the slope.
- Our map does not draw the rise as a layer, but it appears as a gradual flattening of the depth colours.
How the continental rise works
Below the continental slope, the seabed does not drop straight into a flat plain. First it flattens out into a long, gentle apron called the continental rise. Its gradient is lower than the slope's and higher than a typical abyssal plain's, and it gradually merges into the plain [1][2].
The rise is mainly sediment. Over millions of years, rivers and coastal erosion deliver mud and sand to the shelf. Some of that material slumps over the shelf break and rushes down the slope and its canyons in dense turbidity currents. When the flow reaches the foot of the slope it slows, spreads out and drops its load. Layer on layer, the deposits pile up into a wedge or a fan [1].
A rise can reach as far as 500 km out from the foot of the slope [1]. How much sediment it holds depends on how much the nearby continent supplies.
Together, the shelf, slope and rise make up the continental margin. The margin is the transition zone from the continent to the deep ocean floor, and it ends where the rise meets the abyssal plain. Our map does not draw the rise as a separate layer. You can find it by looking for the zone where the steep colour change of the slope eases into the flat, even colour of the deep plain.
An example from our data
The Atlantic is the clearest place to look. The Atlantic Ocean has a mean depth of 3,883 m and a median of 4,242 m. The median being higher than the mean tells you that much of the ocean is a deep plain with a shallower edge around it.
Two of the plains that border continental rises are on our map. The Sohm Abyssal Plain is 917 km from Bermuda, and the deepest cell near it is 5,528 m. The Madeira Abyssal Plain is 605 km from Portugal, at 5,403 m. Those depths are measured by the grid and can differ from published figures.
The features page lists all 18 abyssal plains we have named. The rise is the sediment-built ground between each of them and the continent, where the depth makes the change from slope to plain.
The thing people get wrong
The rise is often skipped in simple diagrams, which show the seabed going shelf, slope, plain. In fact the rise is a distinct stage with its own gentle gradient, and it can be hundreds of kilometres wide [1].
It is also easy to think of the rise as a separate rock formation. It is not. It is a pile of loose sediment on top of the crust, deposited by currents from the continent, which is why it varies so much from coast to coast.
Frequently asked questions
What is the difference between the continental slope and the continental rise?
The slope is the steep drop below the shelf. The rise is the gentler apron of sediment at the base of the slope, which fades into the abyssal plain.
Is the continental rise part of the deep ocean?
It is part of the continental margin, but it is deep, and it merges gradually into the abyssal plain.
Sources
- Continental shelf, Wikipedia.
- Abyssal plain, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against GEBCO_2026 grid).