Final answer:
A medial moraine develops along the center of a glacier where two or more tributary glaciers merge. It provides evidence of the movement and merging of glaciers.
Step-by-step explanation:
A medial moraine develops along the center of a glacier where two or more tributary glaciers merge. It forms when the lateral moraines of the merging glaciers combine. The significance of a medial moraine is that it provides evidence of the movement and merging of glaciers, which can help scientists understand the history and dynamics of glacier formations.