Attenuation Characteristics of Peak Ground Motions in the 1995 Hyogo-ken Nanbu Earthquake.

Abstract

The peak horizontal acceleration and velocity of observed records from the 1995 Hyogo-ken Nanbu earthquake are compared with those predicted from empirical attenuation relations that were derived to be applicable to near-source areas. We found that the observed peak values matched well the empirical attenuation relations. The observed peak vertical accelerations were about half the peak horizontal accelerations when less than 100 cm/s/s. But, the observed peak vertical accelerations tended to be more than half the horizontal ones beyond 100 cm/s/s, and at some sites on soft soil, the peak vertical accelerations were greater than the peak horizontal accelerations. On the other hand, most of the observed peak vertical velocities were about 40% of the peak horizontal velocities independent of the peak amplitudes. At Port Island in Kobe City, remarkable non-linear behavior of soft soil was observed in the vertical array records. The high-frequency shear waves decreased due to liquefaction and the peak horizontal accelerations decayed at the surface. On the contrary, vertical ground motion was amplified by the strong contrast of P-wave velocity in the surface soils. This fact may be one of the causes for greater peak vertical acceleration than peak horizontal acceleration.

Attenuation Relation for West Eurasia Determined With Recent Near-Fault Records From California, Japan and Turkey

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Attenuation relations of peak ground acceleration and velocity in the Southern Dead Sea Transform region

“…As many strong motion records have been accumulated, many attenuation curves have been derived empirically utilizing regression analysis (e.g., Fukushima and Tanaka 1990;Papazachos 1992, 1994;Fukushima and Irikura 1997;Douglas 2003;Gulkan and Kalkan 2004;Ambraseys et al 2005;Kanno et al 2006). However, recent advances in the studies of the attenuation of seismic waves indicate that most of them have no distinct theoretical background.…”

Single-Station Earthquake Characterization for Early Warning

“…T max Attenuation relations describe how the amplitude of seismic waves decrease with distance and earthquake magnitude, and are commonly used to describe peak ground acceleration or velocity for large magnitude events (Campbell, 1981;Joyner and Boore, 1981;Abrahamson and Silva, 1997;Boore et al, 1997;Campbell, 1997;Fukushima and Irikura, 1997;Sadigh et al, 1997;Wald et al, 1999;Field, 2000). We determine our attenuation relations based on the P-wave amplitude and in order to calculate hypocentral distance.…”