In geology, a trough is a linear
structural
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
depression that extends laterally over a distance. Although it is less steep than a
''trench'', a trough can be a narrow
basin or a geologic
rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...
. These features often form at the rim of
tectonic plate
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
s.
There are various oceanic troughs on the
ocean floor
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds.
The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...
s.
Examples of oceanic troughs
*
Benue Trough
The Benue Trough is a major geological structure underlying a large part of Nigeria and extending about 1,000 km northeast from the Bight of Benin to Lake Chad. It is part of the broader West and Central African Rift System.
Location
The ...
*
Cayman Trough
The Cayman Trough (also known as the Cayman Trench, Bartlett Deep and Bartlett Trough) is a complex transform fault zone pull-apart basin which contains a small spreading ridge, the Mid-Cayman Rise, on the floor of the western Caribbean Sea bet ...
*
Hesperides Trough
In Greek mythology, the Hesperides (; , ) are the nymphs of evening and golden light of sunsets, who were the "Daughters of the Evening" or "Nymphs of the West". They were also called the Atlantides () from their reputed father, Atlas (mytholog ...
*
Kings Trough
*
Mariana Trough
The Mariana Trough is an active back-arc basin in the western Pacific Ocean . It is an integral part of the Izu–Bonin–Mariana Arc system.
Location and Bathymetry
The Mariana Trough stretches 1300 km from north to south, about the distan ...
*
Nankai Trough
The is a submarine trough located south of the Nankaidō region of Japan's island of Honshu, extending approximately offshore. The underlying fault, the ''Nankai megathrust,'' is the source of the devastating Nankai megathrust earthquakes, ...
*
Northumberland Trough The Northumberland Trough, also known as the Northumberland Basin, is an element of the structural geology of northern England, the origin of which dates back to the Carboniferous period when a block and basin province was established throughout t ...
*
Okinawa Trough
The (also called , literally "China-Ryukyu Border Trough") is a seabed feature of the East China Sea. It is an active, initial back-arc rifting basin which has formed behind the Ryukyu arc-trench system in the West Pacific. It developed where th ...
in the East China Sea
*
Rockall Trough
The Rockall Trough () is a deep-water bathymetric feature to the northwest of Scotland and Ireland, running roughly from southwest to northeast, flanked on the north by the Rockall Plateau and to the south by the Porcupine Seabight. At the n ...
and others along the rift of the
mid-oceanic ridge
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a ...
*
Salton Trough
The Salton Trough is an active tectonic pull-apart basin, or graben. It lies within the Imperial, Riverside, and San Diego counties of southeastern California and extends south of the Mexico–United States border into the state of Baja Califo ...
*
South Shetland Trough
The South Shetland Trough is an undersea trough located north of the South Shetland Islands, which are a group of Antarctic islands. It is the remnant of a subduction zone where the defunct Phoenix Plate, now part of the Antarctic Plate, subduct ...
*
Suakin Trough
Suakin or Sawakin (, Beja: ''Oosook'') is a port city in northeastern Sudan, on the west coast of the Red Sea. It was formerly the region's chief port, but is now secondary to Port Sudan, about north.
Suakin used to be considered the height ...
[Dinwiddie, Robert et al. (2008) ''Ocean: The World's Last Wilderness Revealed'', London, Dorling Kindersley, page 452.] in the Red Sea
*
Timor Trough
The Timor Trough is an oceanic trough that is a continuation of the Sunda Trench (Java Trench) that marks the boundary between the Indo-Australian plate and the Timor plate. It is separated from the Sunda Trench by a sag near Sumba Island at the ...
See also
*
Oceanic basin
In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, most of the ocean basins are large Structural basin, geologic basins that are below sea level.
Most commonly the ocea ...
*
Thalweg
In geography, hydrography, and fluvial geomorphology, a thalweg or talweg () is the line or curve of lowest elevation within a valley or watercourse. Normally only the horizontal position of the curve is considered (as viewed on a map); the c ...
*
Walker Lane
The Walker Lane is a geologic trough roughly aligned with the California/Nevada border southward to where Death Valley intersects the Garlock Fault, a major left lateral, or sinistral, strike-slip fault. The north-northwest end of the Walker ...
References
Depressions (geology)
Structural geology
{{geomorph-stub