Triggers such as a landslide can cause these entities to undergo a limnic eruption, and thousands of people were asphyxiated by carbon dioxide when one of these named Nyos. Several of them linked in series are called paternoster, and cirques in a glacier cirques can form a type of these called a tarn. Cutting a bend from a meandering river will form the oxbow variety of these, and ones located on volcanoes are the crater 
Triggers such as a landslide can cause these entities to undergo a limnic eruption, and thousands of people were asphyxiated by carbon dioxide when one of these named Nyos. Several of them linked in series are called paternoster, and cirques in a glacier cirques can form a type of these called a tarn. Cutting a bend from a meandering river will form the oxbow variety of these, and ones located on volcanoes are the crater type. For 10 points, name these inland bodies of water, of which a set of five "Great" ones lie on the American-Canadian border.
Triggers such as a landslide can cause these entities to undergo a limnic eruption, and thousands of people were asphyxiated by carbon dioxide when one of these named Nyos.