Summary of Abstract Submission

Abstract Submission No. IO50-11-0021PresentationOral

EXPLORING THE INDIAN OCEAN GEOID LOW

Ajeet Kumar*1, Kishor Gaonkar1, Rajeev Krishnan2, Dr. Dhananjai Pandey1

1 National Centre for Antarctic & Ocean Research (NCAOR), India
2 National Centre for Antarctic & Ocean Research (NCAOR), , India

ABSTRACT :

Geoid anomalies are more responsive to long wavelength density inhomogeneities-deep within the Earth.Therefore it is useful to study the internal processes of the Earth that could lead to such large scale fluctuations. The Indian Ocean Geoid Low (IOGL) is world┐s largest Geoid low, centered near to south of Sri-Lanka and covers a large part of the northern & central Indian Ocean. The geoid fluctuations here is of the order of -100m which is much significant compared to the other parts of the world. Our objectives are to explore possible reasons attributing to such extreme deficiencies in the geoid height & to understand the crustal influence to the origin of the IOGL. Earlier studies support that the source depths of IOGL ranges from crust to the core mantle boundary & the influence of crust on the geoid height was significant (Spasojevic et al. 2010). An initial segregate study of contribution of these sources of different depths is important. Influence of crust on the geoid was found to be mainly due to the variation of the shape of crustal layers and variation of density inside the layers plays a secondary role (J. Kakkuri, 2003). We conducted a detailed marine 2D regional seismic survey across IOGL area which consisted of regional seismic profiles. The data is marked with complex geological features like long wavelength folding, deep penetrating faults and unconformities.We also acquired Active OBS data in IOGL region which demarcates the Moho boundary across the IOGL region. Through these seismic information we explore the possibility of crustal scale contribution for Geoidal low.