Existing comment:
Landscape Arch:
September 1, 1991 -- Hikers thought they heard cracks of thunder from distant clouds. Visitors resting under Landscape Arch noticed loud cracking and popping noises overhead. They fled as small rocks tumbled from the slender 305-foot long span. Moments later, a 60-foot-long rock slab peeled away from the arch's right side. When the dust settled, 180 tons of fresh rock debris lay scattered on the ground.
What caused this cataclysmic event? Water had been slowly shaping the arch for countless centuries, dissolving cement between sand grains, seeping into tiny cracks, freezing and expanding. What had finally upset the delicate balance?
Unseasonably heavy rains the preceding ten days may have filled pore spaces within the sandstone. The added weight may have finally overwhelmed the rock slab in its timeless struggle with gravity. |