PROJECT TOWARDS SIMULTANEOUS VISUALIZATION FOR VARIOUS KINDS OF GEOSCIENCE DATA ON GOOGLE EARTH

1. Scope of the Project

There are numerous kinds of data in the community of the solid earth science, and it is expected to discover a new insight into the structure and/or activity in the Earth's interior by a simultaneous interpretation of multidisciplinary data. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) also has been accumulating various kinds of geoscience data related to the solid earth obtained by observations both on land and in oceans. It is necessary, for the first step, to visualize simultaneously these different types of data in a common platform in order to make a cross-disciplinary research. Google Earth is a powerful tool in this point of view, so that a useful tool that converts geoscience data into KML format is expected to be available for everyone.

The data center of Institute for Research on Earth Evolution (IFREE) of JAMSTEC adopts Google Earth as a common browser for data of the solid earth science, and has been promoting a project to develop the conversion tools to make KML files easily and quickly. Here we introduce the conversion tools developed in the project.

2. Released Conversion Tools from the Project

The present target data to be converted to KML files are seismic tomography data, geomagnetic data, geochemical data of rocks, and navigation data of research vessels of JAMSTEC. The conversion tool for the seismic tomography data is already released as web application software from Pacific 21 website (http://www.jamstec.go.jp/pacific21/). It is possible to download, for example, a KML file of an arbitrary horizontal/vertical cross section of the seismic tomography model of the Earth's mantle proposed by Obayashi et al. (2006) and Isse et al. (2006a, 2006b), setting parameters such as which cross section and area to be displayed on Google Earth.

The conversion tool for geochemical data of rocks provided from two geochemical databases is also available. One database is Geochemistry of Rocks of the Oceans and Continents (GEOROC, http://georoc.mpch-mainz.gwdg.de/georoc/), and another one is Petrological Database of the Ocean Floor (PetDB, http://www.petdb.org/), which archives analytical data (major element composition and isotope ratios, for example) for rocks and glasses sampled from ocean floor.

As a part of this project, we have been developing a conversion tool that enables us to view a global/local geomagnetic field on Google Earth. This tool makes it possible to generate a KML file from a geomagnetic field model given as a table of spherical harmonic coefficients such as International/Definitive Geomagnetic Reference Field (IGRF/DGRF) and NGDC720 models.

We show, in the presentation, examples of the KML converters of the seismic tomography models, the geomagnetic field models, the geochemical data of rocks, and the route data of observation vessels of JAMSTEC. We also show a simultaneous comparison of these data on Google Earth.

3. Summary

Cross-disciplinary cooperation between various fields in the solid earth science becomes more and more important to clarify the Earth's interior. A simultaneous visualization of different types of geoscience data is essential in order to achieve this purpose, and Google Earth is the best solution for a data browser. We are going to provide more conversion tools as web application and/or Java application not only for the data presented here but also for other types of data. We believe our conversion tools will give a force to the simultaneous visualization, and then bring a new discovery in the Earth's interior.

References

Obayashi, M., H. Sugioka, J. Yoshimitsu, and Y. Fukao, High temperature anomalies oceanward of subducting slabs at the 410-km discontinuity, Earth Planet. Sci. Lett., 243, 149-158, 2006.

Isse T., D. Suetsugu, H. Shiobara, H. Sugioka, K. Yoshizawa, T. Kanazawa, Y. Fukao, Shear wave speed structure beneath the South Pacific superswell using broadband data from ocean floor and islands, Geophys. Res. Lett., 33, L16303, doi:10.1029/2006GL026872, 2006.

Isse, T., K. Yoshizawa, H. Shiobara, M. Shinohara, K. Nakahigashi, K. Mochizuki, H. Sugioka, D. Suetsugu, S. Oki, T. Kanazawa, K. Suyehiro, and Y. Fukao, 3-D Shear Wave Structure beneath the Philippine Sea from land and ocean bottom broadband seismograms, J. Geophys. Res., 111, B06310, doi:10.1029/2005JB003750- 2006b.