But Ridley and his colleagues have found structures in lava rock from the seabed that they believe have been formed by the contact of very hot water vapor with lava. The rock is traversed by the remnants of small cavities that were probably created by water vapor bubbles, but later collapsed because of the high pressure. This thesis is supported by a salt deposit on the walls of the cavity remains.
The researchers believe that water vapor can penetrate from below into the lava as it flows over the young, rugged ocean floor. The water trapped in small ruts and holes is evaporated and rises into the lava. Ridley and colleagues estimate that a 0.5 centimeter thick layer of water, despite the high pressure that raises the boiling point of the water to a few hundred degrees Celsius, is transformed within five minutes into a ten centimeter thick layer of water vapor. The water vapor bubbles rising into the lava then reduce the friction of the lava with its already solidified outer skin and thus allow the lava to flow for several kilometers, even in terrain without a great incline.