A rille
trench fosse
A valley in the ocean is typically referred to as a "trench." Oceanic trenches are deep, narrow depressions in the seafloor, formed by tectonic plate subduction. The Mariana Trench, for example, is the deepest ocean trench in the world. These features are significant for marine geology and biodiversity.
Trench
A long, narrow deep ditch.
The word you are looking for is "trench." Trenches are long and narrow depressions in the seafloor characterized by very steep sides.
A narrow furrow is typically referred to as a groove. It can also be called a trench or a rut, depending on the context in which it is used.
The ridge of a trench is the parapet.
An excavation in the ground that is generally deeper than it is wide and narrow compared to its length
trench fosse
The Mariana Trench in the western Pacific Ocean is an example of a trench. It is the deepest known oceanic trench, reaching a depth of about 36,070 feet (10,994 meters). Trenches are long, narrow, and deep natural features on the seafloor, often formed by the tectonic forces of converging plates.
Narrow strip or Deep strip footingThis type foundation is used for normal soil and normal loads which just need 0.9m dept cheep in cost construction.The essential feature of the narrow strip foundation is that the trench is too narrow to be dug by labours working in trench. It depends for its success in the ability of a mechanical excavator, such as a light tractor-mounted back-actor with a narrow bucket to dig the trench, which must be self-support until it can be backfill with concrete.It can't be economical be use in very soft clays or water bearing sand which support by close timbering.From Lewis Telfer
A long narrow hole dug in the Earth is called a trench. Trenches are often created for various purposes such as construction, agriculture, or military purposes.