What are the dangers posed to the united states by the yellowstone volcano?

THE threat of Yellowstone erupting in the future and the sheer size of the supervolcano means Yellowstone is the most dangerous natural cataclysm on Earth, a geologist has warned. Yellowstone volcano's last three major eruptions occurred 640,000, 1.3 million and 2.1 million years ago respectively.

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.