Volatiles and Fluids in Subduction Zones

Overview Theme A6

Integration of geological, geophysical, petrological and geochemical data in time and space and their meta data in a synoptic model of the Central American and Central Chilean margin is the main goal of this new sub project. SFB 574 data (or more general "information") of structural geology, geochronology, volcanology/geochemistry and stratigraphy/sedimentology at the Central American (later Central Chilean) margin are widely scattered. An integration of the spatial and temporal relationships between these data sets, which all bear on the development of Central America/Central Chile and the adjacent oceanic areas, does not exist. Thus, the project proposes the integration and analysis of a wide variety of data types, including but not limited to the observations of the SFB 574 research group, in a synoptic model. It will consist of a series of digital maps which display structures and interacting processes between the upper and lower plate at different scales. The spatio-temporal pattern of topography, magmatism, deformation, seismicity and derivative processes of basin formation and trench parallel faults yield insights in the underlying dynamics and processes at a convergent-margin.

Integrated analysis of the space-time dynamics of seismicity will further contribute to the fundamental understanding but also add important information with respect to earthquake hazard assessment. Integration of various data sets and adoption of existing software tools addressing the specific nature of seismicity data will allow the correlation of seismicity with crustal structures, processes as well as models and for the detailed study of seismogenesis, i.e., the spatio-temporal evolution of seismicity. The resulting functionality will have specialized visualization, spatial querying and statistical analysis capabilities highly relevant also to earthquake hazard assessment. A correlation between seismicity and potential fields, feasible once all relevant data sets are integrated into the synoptic 3D information system, will support the correlation of large trench-parallel gravity variations.

In addition the sub project will focus its research on a “roughness” study of the incoming plate at the Central American and Chilean margin. Roughness depends on age, temperature and flexural rigidity which will be calculated from potential field analysis in sub project A2 and compared with open data bases (magnetic field, magnetic isochrones); analysis by spatial curvature methods and the 3D GIS will provide new insight into the structure and behaviour of the continental margin. We will analyse the topography on land (90m x 90m DEM of SRT mission) and bathymetry which will be provided by sub project A1 and/or by the GEBCO bathymetry - 1.8 x 1.8 km) and correlate findings with large scaled potential fields and geoid.

In the second half of the working period we will build up an experimental graphics cave for 3D visualization of SFB data.