- Ground-motion model is:
where Y (T) is in cm∕s2, b1(0) = 1.1064, b2(0) = 0.2830, b3(0) = 0.0076, b4(0) = 0.6322 and σ = 0.303
for horizontal PGA and b1(0) = 0.7134, b2(0) = 0.3091, b3(0) = 0.0069, b4(0) = 0.7421 and σ = 0.301 for
- Records from 225 stations of K-Net network with 39.29 ≤ V s,30 ≤ 760.25m∕s (mean V s,30 = 330.80m∕s.
- Select earthquakes that occurred within the region of the boundary of the Okhotsk-Amur plates (NE Japan
bordering Sea of Japan) defined by its horizontal location and vertically, to exclude earthquakes occurring
in other plates or along other boundaries.
- Focal depths, D, between 8 and 43km with mean depth of 20.8km.
- Mean value of M is 4.72.
- Mean repi is 84.67km.
- State that exclude records with PGA < 5cm∕s2 (although ranges of PGAs given include records with PGA
- Horizontal PGA range: 4.15–411.56cm∕s2. Vertical PGA range: 0.50–163.11cm∕s2.
- Originally use this form: log Y (T) = b1(T) + b2(T)M - b3(T)D - log(R) + b5(T)R but find b5(T) > 0.
Regress using the 379 records from sites with V s,30 > 300m∕s and still find b5(T) > 0 but report results
for investigating site effects.
- Plot residuals w.r.t. rhypo and find mean of residuals is zero but find some high residuals.
- Note that need to refine model to consider site effects.