Lava flow moves primarily as molten rock beneath a cooling, solidifying crust.
Here's a breakdown of the process:
- Cooling and Crust Formation: As lava flows across the surface, the upper layer is exposed to the air and cools rapidly. This cooling causes the molten rock to solidify, forming a rocky crust.
- Movement Beneath the Crust: Beneath the hardened crust, the lava remains molten and continues to flow. This molten lava pushes against the solidified crust.
- Crustal Breakage and Tumbling: The pressure from the moving molten lava beneath causes the brittle, rocky crust to fracture and break into pieces. These broken pieces are then carried along by the moving lava.
- Rolling and Tumbling: As the flow continues, the fragments of the rocky surface are rolled and tumbled along, contributing to the flow's forward movement and shaping its overall texture.
In essence, lava flow movement can be visualized as a conveyor belt: the molten lava beneath is the belt, and the broken pieces of the crust are the items being carried along. The cooling and solidification of the surface, followed by the pushing of the molten lava beneath, is what drives the movement of the flow.
