|MadSci Network: Earth Sciences|
It is impossible for several different reasons. Lets look at several aspects of this. To begin with, it is not just the crust, which floats on the liquid core, but also the entire mantle. The crust plus mantle make up more than half the radius of the earth. The mantle is plastic, but it flows at a very slow rate (millimeters per year), to the casual observer it is "rock solid." Some quick calculation I did indicate that to move the crust and mantle you would have to supply enough force to accelerate about 40% of the total mass of the earth in a different direction. That's 4 x 10^24 kg (4 million billion billion kilograms or 40 thousand billion megatons!) of crust and mantle. In addition, the earth is already rotating, so it's not just a matter of simple acceleration, one must take into account the substantial rotational inertia of that spinning mass (more math than I want to do at this hour). Think about how hard it is to change the axis of a spinning gyroscope. Furthermore, the earth has a constant feedback process that tends to keep the mass distribution of the earth in a constant orientation relative to the axis of rotation. Since only the lithospheric plates and their mantle roots are non-uniform, the earth's axis tilts very slowly as the plates drift, so as to keep the continents as closew to the equator and as evenly distributed about the equator as possible. This tendency would couteract any attempt to move the crust. Then there's the issue of using nuclear explosions at all. We can start with the question of whether there is enough fissionable material in the whole earth to provide even a tiny fraction of the number of explosions needed. Even more important is the issue that what makes nuclear weapons so incredibly devastating as weapons makes them much less effective as propulsion devices. A great deal of the mass is converted into heat and light. Far more efficient propulsion is acheived by a mass cannon. Accelerating large masses to orbital escape speeds along something like a mag-lev track provides a very efficient propulsion through Newton's third law. The end result, however, is that in order to move the crust and mantle, you'd have to throw a significant amount of it away, which definitely defeats the purpose. The final issue is that the earth is a sphere and the crust is all interlocking, so if you could move Texas away from the equator, you would have to move something, like Europe, closer to it and something, like Australia further from it. I'm certain the Europeans and Australians would not be in favor of that. In addition, reorienting the earth's oceans would change the patterns of ocean currents and would have significant and unpredictable consequences for the climate amd food webs of the entire earth. Your question seems to motivated by concern over possible effects of human accelerated global warming. If so, there are many more practical solutions that already exist, all focused on using less fossil fuel. Use every energy conserving strategy available (compact fluorescent bulbs, passive and active solar design, hybrid fuel vehicles, programable thermostats, etc.), ban the construction of new fossil fuel energy plants to force conservation, tax gasoline until our prices mirror the Europeans, etc. Sure these strategies cost $, but not nearly as much as an uncontrolled climate change would. David Smith, Ph.D. (who lives above the 70 meter maximum sea level rise), Geology, Environmental Science, and Physics La Salle Univ., Philadelphia, PA
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