YELLOWSTONE NATURE NOTES

A PREDICTION FOR THE FUTURE

We have seen mountains rise from the sea floor, volcanic action on a grandiose scale, and glaciation, earthquakes and hydrothermal activity as important factors in shaping the landscape of this national park.

It is always interesting to speculate on the geologic future. An erosion cycle is now in progress. Streams, under the relentless pull of the force of gravity are deepening and widening their canyons. The plateaus will gradually be reduced as the broad, flat interstream divides are narrowed, and eventually what is now plateau will change to a landscape of rugged topography with sharp knife-like divides separating the streams. If not interrupted by mountain building forces the cycle will continue toward an ultimate base leveling of the land with all topography reduced to a monotonously flat surface.

The future of Yellowstone's heat resources is less susceptible to prediction. We know that hot spring and geyser activity dates back to a time before the glacial epoch and that within historic times no measurable decline in thermal activity has been detected. Could the increased heat flow in the geyser basins since the earthquakes be caused by a warming up of the magmatic hearths and therefore indicate a trend toward renewed volcanic action? Or, is the heat increase due only to agitation of the fracture systems underground permitting a freer circulation of water and magmatic gasses? Careful observations in the years ahead should provide the answer. Certainly we can rest assured that park visitors for generations to come will see "living geology" in Yellowstone but it will be different from that of today.

If we could imagine a movie camera timed so that the shutter clicked once every one hundred years, then it would take a reel of film almost one mile long to document the history of the earth. The geologic changes that man has seen in Yellowstone since its discovery would represent but one frame in the most exciting story ever filmed.

When viewed in this perspective, one earthquake that seems so catastrophic to us in recorded history is seen as but one pulse beat in the endless sea of time. Accordingly one can see how foolish it is to ask, "Will there be another earthquake?" Of course there will, but neither the time nor the place can be predicted with certainty. Without earthquakes we would not have the Yellowstone as we know it today.