For example, the 5-km rule, as a critical distance of fault grouping and/or segmentation, proposed by Matsuda (1990), is widely applied in Japan to define a fault zone that has the potential to generate a large earthquake.
To effectively reduce uncertainty of fault interpretation, we use an approach derived from the research achievements of Soliva and Benedicto (2004), applying the "relay displacement (D, the aggregate displacement measured at the fault overlap center)/separation (S, the vertical distance of fault overlap)" to quantitatively affirm fault growth stages.
To estimate the distance of a fault, impedance based fault location methods are applied with transient fault data of both ends protection relays and both DFRs installed in a line.
These are geology (lithology), fault density, distance to fault, relative permeability of lithologies, elevation, slope aspect, slope steepness, curvature, plan curvature, profile curvature, topographic wetness index, stream power index, sediment transport capacity index, drainage density, distance to drainage, land use/cover, and precipitation.
Frequency content of the design earthquake, represented by the Ap/Vp ratio (i.e. ratio of peak ground acceleration (Ap) to peak ground velocity (Vp)), is a function of the earthquake magnitude, distance to fault, faulting mechanism and site class.
The geographical factors included elevation, gradient, vegetations coverage (normalized difference vegetation index), access condition (distance to main roads), water shortage condition (distance to rivers) and the geological background (distance to faults) of the villages.
Although these models readily explained the observed crustal deformation, they were unable to model an offshore fault along the Sagami Trough because of difficulties related to the distance of the offshore fault from the shoreline.
As observed from the existing growth trends until 2006, urban growth policies have not paid serious attention to risk assessments factor such as distance to faults in development of the city which can be a major challenge at high dense urban areas.
Figure 11 shows the relationships between fault distance and PGVobs/PGV700exp estimated from Mw and the adjusted M. The total variance of PGVobs/PGV700exp was reduced in all ranges of fault distance by the adjusted M (Figs. 11 a, b)).
It is also hard to fix the range of fault distance corresponding to misfit for each earthquake.
Thus, we do not limit the range of fault distance near the fault when adjusting M and estimating the station corrections.
