Evaluation of Earthquake Territory in Lombok using Statistical Method

Lombok Island is one of the regions in Indonesia which has relatively intermediate to high seismicity
level. Therefore, researches on earthquake evaluation are needed in Lombok. The study aims to
determine and map seismotectonic parameter and reoccurrence period of earthquake in Lombok Island
which is located at 8
o
10’
00”
– 9
o
05’
00”
S and 115o
46’
00”
– 117o
05’
00”
E. This means that Lombok is
an area with medium to large earthquake. The study focuses to evaluate and observe seismicity level
change before large earthquake happens in Lombok Island based on statistical method. In this study,
identification of activities, collection and data analysis of earthquake source location in Lombok Island
is conducted. The value of b is found by applying the method of maximum likelihood whereas the value
of PGA is obtained by conducting a calculation which uses empirical method of ground acceleration
and Esteva empirical formulation in order to find a new empirical formulation. The result of the value
of b is around 0.502. This shows that most of the researched area has quite high seismicity activism and
the result is in line with calculation conducted by B.Guttenberg and C.F. Ritcher with constant values a
and b are 8.63 and 0.502.