What causes the force that pushes magma from the magma chamber through the pipe and vent of a volcano? gravity water flow expanding gases convergent boundaries

The force that pushes magma from the magma chamber through the pipe (conduit) and vent of a volcano is primarily caused by **expanding gases**. **Explanation:** - **Expanding Gases:** As magma resides in the magma chamber, volatile substances (like water vapor, carbon dioxide, and sulfur dioxide) dissolved in the magma start to exsolve (separate) as the magma rises and pressure decreases. These gases expand, increasing the internal pressure within the magma chamber. This pressure forces the magma upwards through the volcanic conduit and out of the vent during an eruption. - **Gravity:** While gravity acts on the magma, pulling it downward, it is the internal pressure from expanding gases that overcomes gravitational forces to drive the magma upward. - **Water Flow:** Water flow is not a primary driver in the movement of magma within the volcanic system. However, water can interact with magma and influence eruption dynamics, such as triggering explosive eruptions when it rapidly vaporizes. - **Convergent Boundaries:** Convergent plate boundaries are tectonic settings where plates move towards each other, often leading to magma formation. While they play a crucial role in magma generation, they are not the direct force that pushes magma through the volcanic conduit. **Correct Answer:** **Expanding gases**