- Ground-motion model is:
where PGA in in gal, a1 = -5.8, a2 = 2.62, a3 = -0.16, a4 = -1.33 and σ = 0.42.
- Data from 8 stations in Pithoragarh region of Kumaon Himalaya (Uttarakhand,India) from 03/2006 to
03/2008. Stations cover area of 11812km2 (minimum inter-station distance is 11km). Instrument trigger
level is 0.1gal so that almost continuous recording so as to record even smallest earthquakes. Sampling
frequency is 100Hz. Records baseline-corrected, corrected for instrument response and filtered.
- Locate earthquakes using HYPO71 for events recorded at ≥ 3 stations and S-P intervals for other events.
- Compute Mw from S-phase source spectrum at each station after correcting for geometrical and anelastic
- Most data have 10 ≤ rhypo ≤ 100km.
- Also derive model using anelastic attenuation term and geometrical decay term in terms of rhypo but find
- Test fit and normality of model to data by plotting: observed v. predicted, cumulative probability plot and
residuals w.r.t. PGA. Find good performance but note some weak tails.