Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Shaul Hurwitz and Blaine McCleskey, research hydrologists with the U.S. Geological Survey. Old Faithful Geyser erupts on a clear winter day in Yellowstone National Park Old Faithful Geyser was named by  Ferdinand V. Hayden , who led the 1871 geological survey of northwestern Wyoming that resulted in the establishment of Yellowstone as the first U.S. National Park in 1872. In the report summarizing the expedition, Hayden wrote: “ [Old Faithful] is so regular in its operations and they occur so frequently that it has afforded unusual facilities for observation ”. There are  many reasons to study geysers , and because of the relative regularity of its eruptions, Old Faithful has attracted a significant amount of attention for scientific research.…