Mineral Guide > How the Earth was Formed > Old Faithful Geyser

Old Faithful Geyser

This picture of the Old Faithful Geyser in action illustrates some of the work of underground water.

In this case, water accumulates some distance below the surface in a cavity which lies in or near a bed of rock which has only recently come to the surface and is still very hot. This water becomes heated until steam is formed. This steam expands and with explosive violence forces upward and out the water in the throat of the geyser.

The whole operation is repeated periodically, as often as the proper conditions of temperature and pressure are met.

That Yellowstone Park is a region of very recent volcanic activity is shown by its numerous active geysers and hot mud springs.

In any elementary physical geography will be found an interesting account of volcanic action and the work of underground water, not only in such cases as those mentioned here, but also in the formation of caverns.

Old Faithful Geyser picture