U.TRGU trough

a long depression of the sea floor characteristically flat bottomed and steep sided, and normally shallower than a trench

30 features in 13 countries.

#CountryFeaturesShare of the world
1AntarcticaAQ15
2Northern Mariana IslandsMP3
3RussiaRU2
4CanadaCA1
5MicronesiaFM1
6United KingdomGB1
7GuamGU1
8IraqIQ1
9JapanJP1
10New CaledoniaNC1
11Solomon IslandsSB1
12TongaTO1
13United StatesUS1
Total30