Also called a shore platform, a wave-cut notch is a narrow flat area that is normally found at the base of a sea cliff or the shoreline of a sea, lake or bay. It forms by the action of waves hitting against the face of the cliff. Wave-cut notches are mostly obvious during low tides when they become visible as huge, flat rocks.
Wave-cut notches are only identified when sand is moved by a storm or during low tide periods. They are formed as waves hit a cliff between the high and low tide lines. Eventually the notches grow to become caves, then are undermined by continuing wave action until the cliff collapses. Once the cliff is the same level as the beach, it becomes less possible for the sea to continue eroding the remaining rock. Given the right conditions, the continuous landward retreat and erosion of the cliff results in a flat, wide rock that looks as if the rock’s foundation has been exposed.
Wave-cut notches sometimes provide evidence about sea levels in the past. When researchers find these raised surfaces behind present-day beaches, they provide evidence of higher sea levels that existed in the geological past. Through studying fossils found in the platform or through scientific dating methods, geologists and geographers can often determine when the platform was formed.