The river erosion rate estimates we obtain from strath terraces are averages over the time since the terrace was abandoned by the river. If the erosion of the river downward into rock occurs only when the sediment supply from the headwaters is low, and this occurs during interglacials, explain why there is an apparent acceleration rate in river incision reported from dating several strath terraces on a single river. You will need to acknowledge the climate history through the last several glacial-interglacial oscillations (recall the d¹⁸O record from deep sea cores).