The North York Moors has several overflow channels which are thought to have cut through the moors during the last glacial period. The largest is Newtondale; which is 15km long and 80m deep. Peak flow would have been around 10,000 cumecs.
Ice lined the current coastline and trapped in water along the moors. Water couldn’t flow out of the ends of glaciers and built up inland in large lakes between the hills and the other glaciers. As the climate warmed, more water pooled there. The area became a glacier-dammed lake. Water level rose until it spilled over the lowest col, at 200m. The volumes of melt-water cut through the Newtondale overflow channel.
A similar process also occured nearby at Lake Pickering, cutting out the Kirkham Abbey Gorge, and several other sites were effected by the glaciers