What was significant about the battle of the somme?

The answer is: There were massive casualties and the Allies gained very little ground

Approximately, the german empire loss around 400,000 while the allied forces loss around 700,000 people during the Battle of Somme. This loss resulted in the failure in obtaining control to the river of Somme, which was a crucial spot for the allies to control the distribution of supplies that occurs in the battle field.

answer; disconfirm the catharsis theory;