Add to ORKGBe-10 and Cl-36 Cosmic Ray Exposure (CRE) dating performed on river polished surfaces of river gorges in a mountain-to-sea river system in the French SW Alps highlights transient erosional events involving incision rates >10 mm a(-1). These events took place during the last two major deglaciation phases following (1) the Last Glacial Maximum (LGM) at 16-14 ka, (2) the Younger Dryas at 8-11 ka, and during the warm and humid Holocene climatic optimum at 4-5 ka. These periods of high incision rates (3->30 mm a(-1)) alternated with periods of low incision rates (<1 mm a(-1)), which probably correspond to a long-term equilibrium between incision and relative uplift. The Alpine river staircase shape profiles evidence local and transient responses...