Dr. Hasih Pratiwi
(Sebelas Maret University, Jl. Ir. Sutami 36A Surakarta, Indonesia)
Title
ESTIMATING EARTHQUAKE RISK BY USING EPIDEMIC TYPE AFTERSHOCK SEQUENCE MODEL APPROACH
(Case Study in Java Island, Indonesia)
Abstract
Physical losses caused by earthquakes are death or casualties and damage to buildings and areas.
Therefore, efforts to reduce the risk of earthquake are very necessary.
Relating to risk or loss generated by earthquake it is of course does not get out of insurance world. Insurance as nonbank financial institution can give guarantee or protection as done by banking sector.
This research discusses a method to estimate earthquake risk by using epidemic type aftershock sequence model.
Calculation of earthquake risk can be determined through a damage probability matrix.
The information contained in the damage probability matrix and in the damage ratios can be combined for defining the mean damage ratio.
Then, based on the estimation of intensity function in epidemic type aftershock sequence model we can formulate the expected annual damage ratio,
and the existing method for calculating earthquake risk is modified to obtain earthquake insurance premium rates.
We use earthquakes data in Java Island obtained from U.S. Geological Survey which consists of time of occurrence, longitude, latitude, magnitude, depth, and catalogue source.
The time span of this research is from January 1, 1973, to December 31, 2010.
Zonation map of earthquake generated in this research is different from the zonation map SNI 2010 issued by Indonesian Ministry of Public Works.
The difference lies on the distribution of earthquake zone, especially in regencies and cities with high risk.
The earthquake insurance premium rates for high and medium intensities obtained from this research are significantly greater than the premium rates issued by PT Reasuransi Maipark Indonesia.
The current premium rates are relatively small when compared with the rates in Turkey and from this research.
Keywords
earthquake insurance, intensity function, epidemic type aftershock sequence model, damage probability matrix.
