This crack was measured to be 10 meters deep shortly after the large earthquake of Southern Lowlands in Iceland, June 21 in the year 2000, measured to be 6.6 on Richter scale.
The picture is taken just south of road number 1, towards the shouth. The fault is right-lateral, so if you would have stood at the side of the moving fault, the other side would have been seen to move to the right hand side.
The side of Ingólfsfjall seen above is actually marked by an earthquake fault, oriented directly N-S. This is just south of 64°N, the central latitude of the South Iceland Seismic Zone. The faults themselves are all parallel, with the average distance of 715 meters in between them.
The South Iceland Seismic Zone reveals the convection rolls, because it extends exactly over one roll from west to east, that is from the town Hveragerði to Hekla Volcano.