Tuesday, August 12, 2008

Arches National Park

From the Vault:

Location: Near Moab, UT, May 2008


Click for Larger Image of Rocks in ArchesI was at Arches National Park for a single day in May with John, Ken and Pam. Since one day is not nearly enough to see the park, I had planned to return to the area after I left Colorado -- but my broken ankle made that plan evaporate. One of the arches I didn't see then I won't ever see -- on August 4th, the first full day I would have been in the park, the 12th largest arch in the park came tumbling down.

Arches National Park is composed of sandstone formations that take a variety of shapes: large standing rocks, hoodoos, walls of rock, and the famous arches. What is now high desert country was, millions of years ago, a huge salty sea. The sea eventually evaporated, leaving enormous salt flats that were subsequently covered by sand. The sand compressed over time into layers and layers of sandstone. The underlying salt layer was very unstable, and began to flow under the weight of the sandstone, causing buckling, shifting, thrusting, and creating cavities and vertical cracks.

Click for Larger Image of People Under ArchAs time went on, wind, water, and ice eroded the softer rock leaving fins scattered throughout the landscape. As the softer rock continued to break off and erode, openings were created in the fins, and these openings continued to expand until they became the arches we know today.

Mother Nature has not finished with Arches National Park -- new arches continue to form, and old arches collapse into rubble. Throughout the park, solid fins can still be seen, and also fins with small holes in their middle -- fins that are on their way to being the arches our descendants will come to see. Existing arches continue to erode, and, as happened August 4th, the arch will collapse when its thinness and cracks make the rock too fragile to support its enormous weight. The park will continue to have arches for a long time to come -- but the landscape will never look the same for very long.

Click for Larger Image of Delicate Arch Click for Larger Image of Moon Over Arch  Click for Larger Image of Pam and Ken at Arches Click for Larger Image of John, Pam And Ken 

1 comment:

Wandrin said...

Fantastic photos. Arches is another favorite -- off season. Going to have to get there again one of these years.