In my last post, I mentioned the large pool of mantle water, about the size of the arctic ocean, that was found under Asia. It is interesting to paint a doom and gloom scenario, as to what would happen if the crust was suddenly breached and this huge volume of high pressure and high temperature water begins to enter the surface of the earth. Water, at the conditions of the mantle, would be something between super critical water (suer dense fluid) and super ionic water (solid). Super ionic water is especially nasty, if subject to a pressure drop. It will explode like TNT, changing phase into super critical water. If a leak started, and super ionic water gets entrained and depressurized, it could blow a hole in the crust. While super critical water would dissolve the remaining crust until geysers of super heat water appears. Picture that Arctic ocean volume of super critical mantle water, leaking up from the ocean floor. As the billions and billions of gallons of super critical water head toward the surface, it will cool and pressure drop and then phase change into high pressure steam. The ocean near the breach, would bubble up with pulses of steam/water causing the ocean to heat up quickly. This massive bubbling action would become something similar to a massive tidal wave generator. There would be one tidal wave after another, as mantle water and steam displace the ocean water. Picture blowing air into a glass of water and the water lifting and falling in a cycle fashion. As it rises and falls, huge waves flow in all directions. As the breach grows, due to supercritical water eating away and dissolving the crust, the rate of steam flow will begin to super heat the local ocean and start to enter the atmosphere as huge plumes of steam. The steam would rise to levels where clouds are rarely found because of the heating of the atmosphere above the breach. Depending on who long this happens, it could cause the entire earth to be covered with high and low level clouds. The local result could be a tornado and hurricane generator. The super sonic updrafts of steam would become sheared by the jet stream spinning off huge storms. The tidal wave generator could go on for weeks, generating one pulse of waves after another, while the addition of the all the new ocean volume of water will totally alter the world's coastlines. At the same time, huge storms will spread out flooding the continents and carving out new rivers; grand canyons. Since the mantle is loosing so much volume, there will be a need to replace this as the crustal plates slide; huge earthquakes, as crust begins to sink.