The true statement is that tarns are found in cirques while fjords are located in glacial troughs. Tarns are small mountain lakes, whereas fjords are deep, narrow sea inlets formed by glaciers. Other options about their depth and shape are incorrect.
The statement Tarns are located in cirques; fjords are located in glacial troughs is TRUE. Tarns are small mountain lakes that are typically found in cirques, which are bowl-shaped depressions on the side of or near mountains, carved out by glacier activity. Fjords, on the other hand, are long, narrow, and deep inlets of the sea between high cliffs or slopes, created by the submergence of a glaciated valley.
It is not correct to say that tarns are always deeper than fjords; fjords can be quite deep due to their formation through glacial activity. Tarns might be deep relative to their size, but they don't match the depth of fjords. Additionally, fjords are not primarily circular; they are usually characterized by their elongated, narrow shape. Tarns are not necessarily linear and can vary in shape.