Figure 47.

A) Diagrams showing the orientation of the local least horizontal principal (LLPS) and local maximum horizontal (LMHC) stress. Breaching is observed to occur opposite the nearby topographic high. B)Example at Vent 3522 (vertical line pattern) showing the relation between the breach direction and the nearby topographic high (cross-hatched area is for older cinder cones and flows; the cinder cone to the south, stipple pattern, is younger than the breached cone).