Martial Law in the United States: Its Meaning, Its History, and Why the President Can’t Declare It (brennancenter.org) The concept has never been well understood. What should be clear, however, is that the president lacks the authority to declare it.
If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind a dam, which marks the downstream limit of the glacial overdeepening.
Tarn (lake) (Wikipedia) A tarn (or corrie loch) is a mountain lake, pond or pool, formed in a cirque excavated by a glacier. A moraine may form a natural dam below a tarn.