2008 National Seismic Hazard Maps - Fault Parameters

2007 National Seismic Hazard Maps-Fault parameters

Fault Name	State
Acala fault	Texas

MODEL VALUES
Slip rate (vertical or horizontal in mm/yr)	0.088
Probability of activity	1

FAULT GEOMETRY
Dip (degrees)	50/40/60
Dip direction	SW
Sense of slip	normal
Rupture top (km)	0
Rupture bottom (km)	15
Rake (degrees)	-90
Length (km)	7

Assigned Dip	Fault Parallel Slip Rate	Width	Characteristic Magnitude	Characteristic Rate	Weight
40	0.14	23.3	6.09	4.65E-04	0.2
50	0.11	19.6	6.09	3.27E-04	0.6
60	0.1	17.3	6.09	2.56E-04	0.2

Comments




The assigned vertical slip rate is calculated from 18 m of offset on middle Pleistocene deposits that are 130-500 ka (Collins and Raney, 1993). The 2002 assigned slip rate is based on the average of the resulting slip rates. Dip of fault changed to 50° based on redefined regional default value (Lund, 2006).
Selected References




Collins, E.W., and Raney, J.A., 1993, Late Cenozoic faults of the region surrounding the Eagle Flat study area, northwestern trans-Pecos Texas: Technical report to Texas Low-Level Radioactive Waste Disposal Authority, under Contract IAC(92-93)-0910, 74 p. Lund, W.R., ed., 2006, Basin and Range Province Earthquake Working Group seismic-hazard recommendations to the U.S. Geological Survey National Seismic Hazard Mapping Program: Utah Geological Survey Open-File Report 477, 23 p.