Mg-rich olivine is stable to pressures equivalent to a depth of about within Earth. Because it is thought to be the most abundant mineral in Earth's mantle at shallower depths, the properties of olivine have a dominant influence upon the rheology of that part of Earth and hence upon the solid flow that drives plate tectonics. Experiments have documented that olivine at high pressures ("e.g.", 12 GPa, the pressure at depths of about ) can contain at least as much as about 8900 parts per million (weight) of water, and that such water content drastically reduces the resistance of olivine to solid flow. Moreover, because olivine is so abundant, more water may be dissolved in olivine of the mantle than is contained in Earth's oceans.