Second, the evidence shown in the trenches suggests that more than one type of faulting occurred. This is important because it shows that the forces deep within the earth's crust, which are released through earthquakes, have changed over time. The English Hills faults are a distinct weakness in the earth's crust. The northernmost edge of the NMFZ is about 20 miles south of the English Hills faults. The degree of that increased risk has not yet been estimated.
Much more work is needed.