In the main it is a broad trough, wider towards the north than towards the south, and unsymmetrical, Hudson Bay occupying much of its north-eastern part, while to the west broad plains rise gradually to the foot-hills of the Rocky Mountains, the eastern member of the Cordillera which follows the Pacific coast of America.
In the north, the Strait of Juan de Fuca and the intricately branching waterways of Puget Sound between the Cascade and the Olympic ranges occupy trough-like depressions which were filled by extensive glaciers in Pleistocene times; and thus mark the beginning of the great stretch of forded coast which extends northward to Alaska.
The Red Sea itself is a great trough bounded by faults along each side.] Climate.
The West Atlantic Trough lying on the western side of the Central Rise widens in the north into the North American Basin, and its, greatest depths appears to be in the Porto Rico Trench, where in 1882 Capt.
The Daniell type consists of a teak trough divided into five cells by slate partitions coated with marine glue.