Why Not Dispose of Waste in Ocean Trenches?
Why Not Dispose of Waste in Ocean Trenches?This is a perennial suggestion: let’s put our most pernicious wastes into the deepest sea, where they will be drawn down into the Earth’s mantle well away from children and other living things. Usually people are thinking of high-level nuclear waste, which is considered dangerous for thousands of years. (That’s why the design for the proposed waste facility at Yucca Mountain, in Nevada, is so incredibly stringent.)Answer: Deep-sea trenches are where one plate dives beneath another (the process of subduction) to be swallowed up by the Earth’s hot mantle. The descending plates go down hundreds of kilometers, where they are not the least bit of a threat. It isn’t completely clear whether they disappear by being thoroughly mixed with mantle rocks—maybe they persist there and are recycled through the plate-tectonic mill, but that wouldn’t happen