What would cause the land to "rise" in a future, post-apocalyptic world?

We are in the future in northern North America (U.S or Canada). The land has "risen" (or more accurately, filled in) with several hundred feet of earth and sand and silt so that a modern city will show only the tops of skyscrapers emerging from the otherwise-even land. The question is what might have caused this?

Additional thoughts: The cause of the cataclysm need not be a single event (nuclear war, asteroid) but rather a cascade of socio-political events starting with a catalyst (e.g. climate change leads to sea levels rising, which exacerbates tensions in the Koreas, which prompts the North Koreans to "¦ etc.) I'll worry about the story. But the larger is issue is how and why land would rise.

ANCHORS (Set parameters for answers)

1. We are in the future approximately 300 years, and the events that change the world happen 100 years from now (i.e. 2117 for simplicity's sake).

2. The world is sparsely populated as a consequences of events. Enough to form sustainable communities, but the existing geo-political world of nation-states is long gone.

3. The skies have changed and the aurora are more visible much farther south (and often) than today.

ENGINES (what drives creativity within those parameters)

A. The timeline can be adjusted but not radically.

B. A single, unlikely coincidence (but not two!) is acceptable (asteroid strikes while X is taking place, leading to "¦)

C. We can play with technological advances during the next 100 years to create new conditions, possibilities or circumstances.

D. [Later addition after several answers posted]. The effects need not be global. It is OK for this to be a regional phenomenon whereas other effects (but the same cause) are felt elsewhere (e.g. the tide goes up in one place as it goes down in another "¦)

posted almost 8 years ago

Arwood‭

1 reputation 1 0 0 0