“Craters are not just vestiges of war. They are geographic testaments to the anthropogenic force of bombs. Research shows that when a bomb bursts, it alters long-term soil formation, vegetation growth, and hydrology. It also affects how people use the land in the future. It’s a phenomenon so disruptive that it has given rise to a new field of science with an evocative name: bombturbation.
“Simply put, bombturbation is the cratering of a land surface and “mixing the soil with an explosive device,” says Joseph P. Hupy, a geographer at the University of Wisconsin-Eau Claire and the father of the field. The device can be an aerial bomb, a propelled explosive, or an “in situ” bomb such as a landmine.
“If you look at a cross-section of undisturbed soil, you’ll see horizons: surface vegetation and organic matter over topsoil, subsoil, parent material (partly weathered rock), and bedrock. A bomb blast shatters those horizons. It releases forceful energy that creates a supersonic shock wave, penetrating soil and rock, setting sediment in motion, and ejecting materials at high speed. A crater forms — its shape and dimensions dependent on the type and strength of the explosion, and the ground where it occurs. Explosions at or below the surface typically result in craters surrounded by a rim of ejected debris. Bedrock is often exposed in the bottom.
“If you look at a cross-section of undisturbed soil, you’ll see horizons. A bomb blast shatters those horizons.
“Each crater is unique, and its future depends on its environment. Over time, leaves and forest litter accumulate in the crater (if they are there), and water percolates through (or not). Organic matter seeps into the underlying bedrock, and microbes flourish (or not). Regardless of local conditions, the crater fosters a new soil environment that would not have evolved otherwise. Different plants take root. Runoff patterns shift. Creatures — human or otherwise — adapt to that new landscape in different ways. It’s not necessarily good or bad, but it’s changed — and that’s critical.”
Text: Karen J. Coates, Bombscapes: Of War and Earth, Undark