No. That is to say, if every nuke on the planet was detonated precisely along a faultline, it wouldn't cause the "sinking" of a continent. However, it would cause a massive earthquake.
Also if you for example drilled around the Yellowstone caldera and placed nukes there, you could cause the "roof" of the caldera to collapse, pressing the soft magma beneath and squeezing it out in a massive supervolcano. This could basically kill all life on the planet, or at least fuck us up severely.