Port Mulgrave is two miles north of Runswick Bay. A week ago the large portion of undercliff in the middle of the picture was at the top of the cliff. A few days ago, the rain-sodden clifftop (it has rained here for the last month) parted company from its parent Yorkshire and slumped down to the beach. Such a collapse is called rotational slip or rotational slide. The cliffs there are 320 (ish) feet and it looks like the clifftop has dropped around half of that. This pic was taken with a telephoto lens which compresses the perspective, so I suspect the slip is 2-300 feet across and the same from from sea to shore. I'll toddle over there on Monday with wellies, a spade, a rock hammer and my GPS and let you all know how big an event this was. And what fossils are to be found. I'll post a 'before' pic tomorrow.
Thursday; heavy rain and northerly gales forecast all day. Just the conditions that caused this slip in the first place.