Drowned tree stumps in intertidal zone, part of a ghost forest. Sunset Bay State Park, Oregon. These tree stumps indicate that this beach was somewhat above sea level when the trees grew, but dropped to below sea level as the result of an earthquake. Carbon dating of the wood indicates the trees died some 1200 years ago. (SrA-32).
Perhaps the most dramatic evidence for recent faulting along the Black Mountains front is the sheer suddenness of the valley-mountain transition –and the linear nature of the fault. This aerial photo also shows a wineglass canyon. The “wineglass” shape derives from the relatively open nature of the canyon at its upper reaches (the “bowl”) and its narrow, steep mouth (the “stem”). Wineglass Canyons also indicate recent uplift because uplift at the canyon mouth keeps pace with erosion and maintains a steep gradient. (ID: SrA-07)
Aerial view of wineglass Canyons and fault-controlled mountain front, Death Valley National Park, California. Wineglass canyons, named for their steep, narrow mouths and broader, gentler upper reaches, (they look a little like wineglasses) indicate recent uplift activity on the bounding fault zone. Faulting continually uplifts the front of the canyon, so that erosion does not have time to widen it. Consequently, the canyon mouth retains a steep and narrow shape. (ID: SrA-06)
The eastern edge: Mt. Timpanogos, in the Wasatch Range of Utah. Mt. Timpanogos is the second highest peak of the Wasatch Range, at an elevation of 11749′. The Wasatch Range rises along the Wasatch fault, which is an active fault, and so poses a significant earthquake hazard to the Salt Lake City region. As evidence of recent faulting, two wineglass canyons can be seen behind the fault on the right side of the photo. (ID: 477-89)
Aerial view of the Salton Sea and Imperial Valley of California, view northward. The San Andreas takes a right step when it reaches the Salton Sea; transfer of the strain from one part of the fault to the other has caused the area between to be pulled apart. That area is now filled in by the Salton Sea. (100128-85)