Page 255 - Contributed Paper Session (CPS) - Volume 4

CPS2219 Hasih P. et al.
which was centered in East Lombok. Then on 8th August 2018, an earthquake
with a magnitude of 5.9 SR was based in Malang, East Java. This research
discusses the conditional intensity function for modeling the transfer of
pressure due to earthquakes through a linked stress release that is applied to
earthquake data in Java Island and Bali-Nusa Tenggara Islands.

2. Methodology
The first step is to determine the form of stress release model and
determine the hazard function of the stress release model. Based on the
hazard function that has been obtained, then the conditional intensity
function of the stress release model is reconstruct. Based on the conditional
intensity function of the stress release model then reconstruct the conditional
intensity function of the linked stress release model. The conditional intensity
function of the linked stress release model obtained applied to earthquake
data in Java and Bali-Nusa Tenggara, determine the initial parameter value
based on existing earthquake data and then estimate the parameters. From
the results of parameter estimation, it is obtained the plot of the conditional
intensity function of the linked stress release model. Furthermore, we interpret
the results of parameter estimation and conditional intensity function of the
linked stress release model.
The elastic rebound theory is a classical theory that can explain the
occurrence of earthquakes. Based on this theory, the point process model is
constructed into a stress release model. According to Lu et al. [1], in the stress
release model, this stress region which controls the probability of the
occurrence of earthquakes. The level of () increases deterministically
between earthquake and is reduced stochastically as a result of an earthquake.
The current value () can be represented in the form
() = (0) = − () (1)
where (0) the initial value, ρ is constant loading rate from external tectonic
forces, and () is the accumulated stress release from earthquake within the
region over the period [0, ) that is () = ∑ 0≤ < ( ), where and ( )

denote respectively time of occurrence and stress release associated with the
-earthquake. The stress release value during an earthquake (( )) is

estimated from the magnitude.
Kanamori and Anderson [3] showed that magnitude M is proportional to
the logarithm of seismic energy released during an earthquake according to
2
the relation = log + . For simplicity, the stress drop during an
3
earthquake is supposed proportional to the square root of the energy
1
released, i.e., ∝ . Then we have the formula
2
( ) = 10 0.75(− 0 )

where is the normalized magnitude.
0
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