| Summary: | Microtremor research has been conducted in North Bengkulu on May 25
until May 28, 2012. This study was conducted to map the distribution of the Peak
Ground Acceleration values (PGA), Seismic vulnerability index (Kg), ground
shear strain (γ), and the thickness of the sediment layer (h), which indicate the
level of vulnerability of a region to the earthquake hazard. Data this research
using three-component seismometer type DS-4A at 29 measurement points data.
The method to analyze data using Horizontal to Vertical Spectral Ratio (HVSR),
to calculation PGA in ground surface layer value using Kanai empirical equations
for earthquake event September 12, 2007 with a moment magnitude of 8.5.
The results of this research shows us that, in North Bengkulu district the
distribution of PGA in ground surface layer values ranged from 152 to 674 gal,
distribution of seismic vulnerability index value (Kg) ranged from 0.3 to 15.5,
distribution of ground shear strain values (γ) ranged from 4,4x10-5 to 2,5x10-3, and
sediment layer thickness (h) ranged from 6 to 127 meters. PGA in ground surface
layer values, Kg, γ are low and h is thin in commonly the District Napal Putih,
Argamakmur, Batik Nau, and Kerkap, whichs suffered the minor damage levels.
While the high value of PGA in ground surface layer, Kg, γ and the thick of
sediment layer (h) is commonly contained in District of Lais, Air Napal, Ketahun,
and Putri Hijau, which suffered the heavy damage level.
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