[DB 1506 (4); OAB 106] The claim is that the rate at which subterranean water comes to the surface from volcanoes, hot springs, and other vents could fill the ocean in 340 million years. This calculation seems to assume that all subterranean water originates inside the Earth and is coming out onto the surface for the first time. In reality, hot springs are largely fed by a recycling process. Water seeps from the surface into underground aquifers, where it sometimes comes into contact with a heat source and returns to the surface as a hot spring. Most volcanic water comes from ocean water that is dragged into the mantle with oceanic plates that are subducted under continents by plate tectonics. Once again, the young-Earth advocates have forgotten the other side of the balance: They assume that the amount of water coming out of the ground remains at the surface and builds up endlessly, neglecting to consider the large amounts of water going back into the ground.