Detonating a nuclear bomb in a volcano would likely have minimal impact, depending on the volcano's type and the bomb's size. A 200 megaton bomb dropped on an Icelandic volcano could result in radioactive lava and pumice being ejected, but it would not effectively close or neutralize the volcano. The explosion might widen the existing vent, potentially exacerbating volcanic activity rather than containing it. Overall, the consequences would be more harmful than beneficial, with significant environmental risks. The discussion highlights the complexities and uncertainties of such an extreme action.