This view down the East Fork Toklat Glacier shows a typical medial moraine. Medial moraines are bands of rock debris that have accumulated on the surface where two separate streams of ice have merged to form a larger glacier. The tributary glaciers carry debris along their beds and margins (lateral moraine) which combine to form a medial moraine when the tributaries converge. Medial moraines tend to grow steeper and wider down glacier as increased melting concentrates more debris on the surface, which in turn increases insulation of the ice and impedes further melting beneath the moraine as the bare ice melts down around it.
