The frequency of earthquakes in the southern of Bali Island was high. The earthquake source came from subduction of the Indo-Australian Plate with the Eurasian Plate in the south and the Flores back-arc thrust fault in the north caused earthquake activities. These activities caused Badung Regency to be vulnerable getting the impact of earthquakes in the form of damage. Risk earthquake in Badung Regency was analyzed in each sub-district to determine side effects and amplification. Firstly, risk earthquake zone analysis was carried out by calculating the Probabilistic Seismic Hazard Analysis (PSHA) of the probability of exceedance 2% in 50 years using the R-CRISIS 2020 software in bedrock. Then, the PSHA on the surface was calculated by adding the data from Vs30 USGS. The amplification value was calculated based on the comparison of the PSHA on the surface and bedrock. Results of the analysis showed that the PSHA in bedrock and surface rocks in Badung Regency for peak ground acceleration (PGA) value were in the range 0. 41 – 0. 51 g. Meanwhile, spectral acceleration (SA) values at T = 0. 2 and T = 1 second respectively in the range of 0. 83 – 1. 08 g and 0. 29 – 0. 44 g. Overall sub-districts in Badung Regency are risk earthquake zone based on the amplification value. The zone that is relatively more risk earthquake when PGA is in the Petang District. The districts that are relatively more risk when SA at T = 0. 2 seconds are in the Districts of Mengwi, Abiansemal, and Petang. Meanwhile, SA at T = 1 second is relatively more risk in Kuta District, North Kuta, and parts of Mengwi.
The frequency of
earthquakes
in the southern of Bali Island was high. The
earthquake
source came from subduction of the
Indo-Australian
Plate with the Eurasian Plate in the south and the Flores back-arc thrust fault in the north caused
earthquake
activities. These activities caused
Badung
Regency to be vulnerable getting the impact of
earthquakes
in the form of damage.
Risk
earthquake
in
Badung
Regency
was analyzed
in each sub-district to determine side effects and amplification.
Firstly
,
risk
earthquake
zone analysis
was carried
out by calculating the Probabilistic Seismic Hazard Analysis (
PSHA
) of the probability of
exceedance
2% in 50 years using the R-CRISIS 2020 software in bedrock. Then, the
PSHA
on the surface
was calculated
by adding the data from Vs30
USGS
. The amplification
value
was calculated
based on the comparison of the
PSHA
on the surface and bedrock. Results of the analysis
showed
that the
PSHA
in bedrock and surface rocks in
Badung
Regency for peak ground acceleration (PGA)
value
were in the range 0. 41 – 0. 51 g. Meanwhile, spectral acceleration (SA) values at T = 0. 2 and T = 1 second
respectively
in the range of 0. 83 – 1. 08 g and 0. 29 – 0. 44 g.
Overall
sub-districts in
Badung
Regency are
risk
earthquake
zone based on the amplification
value
. The zone
that is
relatively
more
risk
earthquake
when PGA is in the
Petang
District
. The
districts
that are
relatively
more
risk
when SA at T = 0. 2 seconds are in the
Districts
of
Mengwi
,
Abiansemal
, and
Petang
. Meanwhile, SA at T = 1 second is
relatively
more
risk
in
Kuta
District
, North
Kuta
, and parts of
Mengwi
.