Djajadihardja, Y. S.

Engels, M.

Flueh, Ernst R.

Gaedicke, C.

Kopp, Heidrun

Lueschen, E.

Mueller, C.

SINDBAD Working Group

Soemantri, D.

English

OceanRep

Geophysical Research Abstracts, Vol. 9, 06762, 2007SRef-ID: 1607-7962/gra/EGU2007-A-06762© European Geosciences Union 2007The Sunda-Banda Arc Transition - First results fromrecent marine geophysical investigations offshoreeastern Indonesia (Part 1)C. Mueller (1), H. Kopp (2), Y. Djajadihardja (3), M. Engels (1), E. Flueh (2), C.Gaedicke (1), E. Lueschen (1), D. Soemantri (3), and the SINDBAD Working Group(1) Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany, (2)Institut für Meereswissenschaften (IFM-GEOMAR), Kiel, Germany, (3) Agency for theAssessment and Application of Technology (BPPT), Jakarta, Indonesia(Christian.Mueller@bgr.de / Fax: +49 511 6433663)After the Indian Ocean Mw 9.1 earthquake and Tsunami from December 26, 2004,intensive research activities offshore northern and central Sumatra have contributedto an improved understanding of this part of the Sunda Arc subduction system, e.g.in terms of upper plate segmentation and outer arc high evolution. However, while abroad database is now available for this part of the Sunda Arc, the also highly activeeasternmost part of this subduction system, e.g. indicated by the south of Java Mw 7.7earthquake and Tsunami from July 17, 2006, has remained almost unexplored untilrecently.During RV SONNE cruise SO190 from October until December 2006, marine geo-physical data have been acquired at the eastern Sunda Arc and the transition to theBanda Arc within the framework of the project SINDBAD (Seismic and GeoacousticInvestigations along the Sunda-Banda Arc Transition). The main goal of this projectis to investigate the relation between the variability of the lower plate and the tec-tonic evolution of the overriding plate in terms of outer arc high formation and evolu-tion, forearc basin development, and accretion and erosion processes of the overridingplate. The study area is especially eligible for these investigations since the subduct-ing Indo-Australian Plate is characterized by rough topography where the Roo Rise issubducting off eastern Java and by smooth oceanic crust of the Argo Abyssal Plain offBali, Lombok, and Sumbawa further to the east.The forearc is responding to differences in the incoming oceanic plate with the ab-sence of a pronounced forearc basin off eastern Java and with the development ofthe pronounced and deep (>4000 m) forearc Lombok Basin off Bali, Lombok, andSumbawa. The eastern termination of the Lombok Basin is formed by Sumba Island,which shows evidence for recent uplift, probably associated with the subduction ofthe continental Scott Plateau. The Sumba area also represents the transition from sub-duction of the oceanic Argo Abyssal Plain underneath the eastern Sunda island arc tocollision of the continental Australian Plate with the Banda island arc.RV SONNE cruise SO190 was subdivided into two legs. During the first leg high-resolution multichannel reflection seismic and potential field data have been acquired,while the second leg was mainly attributed to the deeper structures utilizing wide-angle OBH/OBS measurements. We present preliminary results from the first leg ofthis expedition focussing on the geometry and evolution of the eastern Sunda fore-arc based on almost 5000 km of multichannel seismics, magnetics, and gravimetryprofiles.AcknowledgementsThis project is funded by the Federal Ministry of Education and Research (BMBF)under grant 03G0190B. We thank Captain O. Meyer and his crew from R/V SONNEfor their professional assistance during the cruise.

The Sunda-Banda Arc Transition - First results from recent marine geophysical investigations offshore eastern Indonesia (Part 1)

The Sunda-Banda Arc Transition - First results from recent marine geophysical investigations offshore eastern Indonesia (Part 1)

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