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A BRIEF INTRODUCTION

Earth's Oven How Hot is Old Faithful? Norris Geyser Basin

If you stick one end of a metal rod into a fire, the energy from the heat will excite or agitate the molecules in the metal. Those excited molecules will collide with nearby cooler ones, and transfer energy to them, making them hotter. Eventually, if you hold onto the rod long enough, the heat will be transferred to your hand. That's conduction (and a possible burn, if you don't let go of the rod).

Convection occurs when heat is transferred by the movement of hot liquids or gases, such as air, water, or magma, to a cooler area. We've all learned that hot air rises. This occurs because air expands as it heats, becoming less dense and more buoyant than the surrounding cooler air. The farther the air gets from its heat source, the cooler and denser it becomes, until eventually it begins to sink again. Baseboard heating in a house, hot air balloons, and water boiling in a pot are all examples of convection.

The same principle is at work beneath Yellowstone. The convection of molten rock in the underlying magma chamber transfers heat throughout the Yellowstone caldera. Near the ground’s surface, convection of hot water creates the park’s famous hot springs and geysers.

So much for dry explantions; let's move on to "cooler" stuff!

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