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Sea Arch, California

Erosional Landform Pictures


Sea arches form by wave erosion of coastal headlands. Sea arches are very temporary landforms, in both geologic and human terms. (more below)
Brief step in a coast's downfall
Photo (c) 2003 Andrew Alden, licensed to About.com (fair use policy)
This sea arch at Goat Rock Beach south of Jenner, California, is unusual in that it sits offshore. The usual method of forming a sea arch is that a headland focuses incoming waves around its point and onto its flanks. The waves erode sea caves into the headland that eventually meet in the middle. Soon enough, maybe in a few centuries at most, the sea arch collapses and we have a sea stack or a tombolo, like the one just north of this spot. Other natural arches form inland by much gentler means.

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