Effect of Magma Solidification under High Pressure on Mechanical State of Lithosphere.

Plate tectonic activity is closely related to the lithosphere and is the physical source of major geological activities such as earthquakes, but its dynamic mechanism is not clear. This paper will explore the force source mechanism of plate movement by analyzing the influence of magma solidification in a highpressure environment inside the Earth on the mechanical state of the lithosphere. The Earth as a whole is constantly radiating heat into outer space, and its interior is in a state of liquid-solid coexistence under high pressure and high temperature. The solidification process of molten magma has continued since the formation of the Earth, and this liquid-solid transition will result in density changes and latent heat release in the Earth's interior, reducing the pressure and supporting force at the bottom of the rigid lithosphere. We found that the lithosphere is not strong enough to support its dead weight, and any pressure fluctuations at the bottom destabilize its mechanical structure. Due to the constraint of rigid and brittle lithosphere, the solidification of magma under high pressure in the Earth will inevitably lead to the change of the mechanical state of the lithosphere. Under the action of gravity, the interaction between plates intensifies, and local stress accumulation exceeds the strength limit of rocks, leading to fracture in the lithosphere. The accumulated stress is released in the weak zone of the lithosphere through geological activities such as earthquakes and adjusts itself to reach a new mechanical equilibrium. And plate boundaries are the weakest parts of the lithosphere, so there's a lot of seismic activity. The above process is repeated over and over again, and this is where the driving force of plate movement comes from. [ABSTRACT FROM AUTHOR]