question: How are medial moraines formed ?
answer: when two different glaciers merge and the lateral moraines of each coalesce to form a moraine in the middle of the combined glacier
turker_answer: Medial moraines are formed when two different glaciers merge and the lateral moraines of each coalesce to form a moraine in the middle of the combined glacier .
rule-based: Medial moraines are formed by when two different glaciers merge and the lateral moraines of each coalesce to form a moraine in the middle of the combined glacier .