It had to have been quite a sight to the soldiers of that era.
It was the forerunner to the
Hawthorn Crater and the
Lochnagar Crater during the Battle of the Somme on 1 July 1916 (along with the 15 others detonated on that day).
The Hawthorn detonation was filmed and there's a Quicktime movie on the link(!) - it shows up occasionaly on TV.