Skip to main content

Table 1 True, first-guess, and optimized values of frictional parameters in each subregion (Fig. 2a) in the numerical experiments, and the values of cost function calculated by using Eq. (7)

From: Adjoint-based direct data assimilation of GNSS time series for optimizing frictional parameters and predicting postseismic deformation following the 2003 Tokachi-oki earthquake

Region True values First-guess values Optimized values
Exp. 1 Exp. 2
1
 AB (kPa) 8.00 6.00 8.13 6.98
 A (kPa) 60.0 60.0 37.0 50.2
 L (mm) 30.0 50.0 47.3 49.0
2
 AB (kPa) 10.0 8.00 7.18 9.00
 A (kPa) 40.0 40.0 37.3 49.7
 L (mm) 10.0 10.0 9.73 9.03
3
 AB (kPa) 6.00 7.00 7.03 7.95
 A (kPa) 20.0 30.0 28.0 21.0
 L (mm) 20.0 18.0 17.3 17.0
4
 AB (kPa) 6.00 8.00 6.19 8.95
 A (kPa) 20.0 40.0 20.5 30.6
 L (mm) 20.0 20.0 20.3 19.0
5
 AB (kPa) 8.00 6.00 7.61 6.99
 A (kPa) 60.0 60.0 68.8 69.7
 L (mm) 10.0 10.0 9.96 9.04
6
 AB (kPa) 10.0 6.00 8.29 4.99
 A (kPa) 40.0 60.0 63.2 50.0
 L (mm) 10.0 10.0 10.5 11.0
7
 AB (kPa) 10.0 12.0 11.4 11.0
 A (kPa) 40.0 50.0 56.1 60.0
 L (mm) 20.0 17.0 18.3 18.0
8
 AB (kPa) 6.00 8.00 6.77 7.00
 A (kPa) 20.0 20.0 29.5 30.0
 L (mm) 30.0 20.0 21.4 21.0
9
 AB (kPa) 8.00 8.00 11.5 9.00
 A (kPa) 60.0 40.0 33.7 30.0
 L (mm) 10.0 8.00 9.17 9.00
Cost function (assimilation period)
 Exp. 1 0 3.80*101 2.41*10−2  
 Exp. 2 2.04*103 2.10*103   2.03*103
Cost function (prediction period)
 Exp. 1 0 2.82*102 4.58*10−1  
 Exp. 2 2.95*103 3.20*103   3.10*103