Here's how it works:
1. Heat Source: Magma, located relatively close to the Earth's surface, heats the surrounding groundwater.
2. Pressure Buildup: The heated water expands, increasing the pressure within the underground reservoir.
3. Eruption: When the pressure exceeds the strength of the surrounding rock, the water erupts from the ground, often with great force.
4. Geyser Cycle: After the eruption, the reservoir refills with cooler water, and the cycle begins again.
Famous examples of geysers include Old Faithful in Yellowstone National Park and Strokkur in Iceland.