1495
Development of Map of Maximum Considered Earthquake Geometric Mean (MCE
G
)
PGA for Earthquake Resistance Building Design in Indonesia
Élaboration de la carte de moyenne géométrique du tremblement de terre maximum considéré
(MCEG) PGA pour la conception antisismique des bâtiments en Indonésie
Irsyam M., Asrurifak M., Ridwan M., Aldiamar F., Wayan Sengara I, Widiyantoro S., Triyoso W., Hilman D.,
Kertapati E., Meilano I., Suhardjono
Team for Revision of Seismic Hazard Maps of Indonesia 2010
Hendriyawan, Simatupang P.T., Muhammad I.
Indonesian Society for Geotechnical Engineering (ISGE)
Murjanto D., Hasan M.
Ministry of Public Works, Indonesia
ABSTRACT: This paper presents the development of Maximum Considered Earthquake Geometric Mean (MCE
G
) PGA map of
Indonesia. The map was developed by combining probabilistic approach for 2% probability of exceedance in 50 years and
deterministic approach. The study was performed to develop hazard map of Indonesia for revision of the hazard map in the Indonesian
Earthquake Resistant Building Code SNI-03-1726-2002.
The seismic parameters used in this study were derived from published
journals, proceedings, previous researchers and by considering latest geological and seismological data. Earthquake source parameters
were determined based on earthquake catalog, geological and seismological information of active faults. Seismic sources were divided
into subduction, fault, and background zones by considering recurrence relationship that included truncated exponential model and
pure characteristic model. Geometry of fault and subduction were represented by three-dimensional (3D) models based on the result of
tomography, while slip-rates of faults were determined by considering the results of GPS measurement. Background source zones
were modeled using gridded models based on spatially smoothed earthquake rates. Finally map of Maximum Considered Earthquake
Geometric Mean (MCE
G
) PGA was then developed by combining probabilistic and deterministic results.
RÉSUMÉ: Cet article présente l’élaboration de la carte de moyenne géométrique du tremblement de terre maximum considéré
(MCE
G
) PGA de l'Indonésie. La carte a été élaborée en combinant une approche probabiliste pour une probabilité de 2% de
dépassement en 50 ans, et l'approche déterministe. L'étude a été réalisée en vue de développer la carte des aléas de l'Indonésie dans le
cadre de la révision de la carte des risques du Code indonésien du bâtiment résistant aux tremblements de terre SNI-03-1726-2002. Les
paramètres sismiques utilisés dans cette étude ont été tirés de revues scientifiques, de comptes rendus de congrès, de contributions de
chercheurs précédents et de la prise en considération des données géologiques et sismologiques les plus récentes. Les paramètres des
sources des tremblements de terre ont été déterminés sur la base du catalogue des séismes, ainsi que d’informations géologiques et
sismologiques concernant les failles actives. Les sources sismiques ont été classées en zones de subduction, zones de faille et zones de
bruit de fond en considérant une loi de retour établie sur la base du modèle exponentiel tronqué et du modèle caractéristique pur. La
géométrie de la faille ou de la zone de subduction ont été représentées par des modèles tridimensionnels (3D) basés sur le résultat de
la tomographie, tandis que les vitesses de glissement des failles ont été déterminées à partir de mesures par GPS. Les sources des zones
de bruit de fond ont été modélisées à l'aide de modèles de grilles basés sur un lissage spatial de la fréquence des tremblements de
terre. Finalement, la carte de moyenne géométrique du tremblement de terre maximum considéré (MCE
G
) PGA a été construite en
combinant les résultats probabilistes et déterministes..
KEYWORDS: Maximum Considered Earthquake Geometric Mean, seismic hazard analysis, deterministic, probabilistic approach
1. INTRODUCTION
Since the seismic hazard map of Indonesia was published in
SNI 03-1726-2002 that partially adopting the concept of UBC
1997, several great earthquakes have occurred in Indonesia
including the 2004 Aceh Earthquake (Mw 9.0-9.3) which was
followed by giant tsunami, the 2005 Nias Earthquake (Mw 8.7),
the 2009 Tasik Earthquake (Mw 7.3), the 2009 Padang
Earthquake (Mw 7.6), and the latest 2012 Simeuleu Earthquake
(Mw 8.5). These earthquakes urgently underline the need to
better reflect potential larger earthquake disasters faced by the
nation predictably in the future and to consider the new
conceptual approach and technological shift shown in the
transition of UBC 1997 to IBC 2000 which evolved further to
current IBC 2009.
This paper presents the latest study in developing map of
Maximum Considered Earthquake Geometric Mean (MCE
G
)
PGA of Indonesia using probabilistic and deterministic
approaches. The map was developed from the basis of updated
available seismotectonic data, implementing new fault models,
and incorporating new ground-motion prediction equations. The
seismotectonic setting of the Indonesian region was evaluated in
order to develop a seismic source model for input to seismic
hazard analysis (SHA). The source models were defined based
upon earthquake catalogs, tectonic boundaries, and fault
information. The characteristics of the major tectonic feature
used in this study were based on historical earthquakes data in
the catalog and the seismotectonic setting of Indonesia, where
the seismic source models were composed of background
seismicity, fault sources, and subduction sources (Irsyam, et al,
2010).
2. SEISMIC SOURCE MODELS
Seismic source model was defined as the zones that have the
same degree of the earthquake, whichever each point in the
zone has the same probability of accident in the future. The
model was developed using earthquake catalogs, tectonic
boundaries, and fault information. The earthquake catalog
covered earthquake period between 1900 to 2009, relocated
catalog by the year 2005, and area between 90
o
E to 145
o
E
longitudes and 15
o
S to 15
o
N latitudes.
