The phrase "deep trough" is grammatically correct and can be used in written English.
Example: The farmer dug a deep trough in the ground to channel water to his crops.
At the same time, however, a deep trough sat over Alaska, dumping record snows.
The Gartner Hype Cycle has Big Data sliding into the long, deep "trough of disillusionment".
"Volumes are bumping along the bottom and it's a particularly deep trough we're in.
Each of the last three peaks in house prices in 1979, 1989 and 2007 was followed by a deep trough.
A model for predicting pH and Electrical Conductivity (EC) responses of a deep trough hydroponic system is developed.
Beneath a covering of glacial material, relatively soft sandstones make up the floor of the vale, which forms a deep trough in the Welsh uplands.
Since then his career has been marked by deep troughs as well as sublime peaks.
He has had a rollercoaster career, with deep troughs and big highs.
The Flyers' path has been a roller-coaster thrill ride, deep troughs of incompetence alternating with lofty peaks of achievement.
Deep troughs in the jet stream have been seen regularly in the past few years affecting the east coast of the US, western Europe and central Asia.
South-west of the city, the Philippine Sea tectonic plate dives down under the Eurasian continental plate along two deep troughs, bending the Eurasian plate down with it.
