How is high temperature water recovered from deep earth sources heated?

High temperature water recovered from deep earth sources is primarily heated by volcanic activity, specifically from magma. This magma is molten rock that is found beneath the earth's surface, and it can reach extremely high temperatures. As magma rises and comes into contact with groundwater or other water sources, it transfers heat, effectively warming the water significantly.

This process is a key mechanism in geothermal energy production, where hot water or steam is harnessed from the earth to generate power or provide direct heating. Other options, while they relate to geological processes, do not primarily contribute to the heating of deep earth water sources in the same direct way that volcanic activity does. For instance, solar radiation affects surface temperatures but does not penetrate deeply into the earth. Radioactive decay of the earth's core contributes to the overall heat of the planet, but it is not a significant source of heat for specific water sources at depth. Similarly, the shifting of tectonic plates can influence geological activities, including volcanic eruptions, but it is not directly responsible for heating water in deep earth sources on its own.