Modeling Mantle Dynamics in the Banda Sea Triple Junction – Exploring a Possible Link to El Niño Southern Oscillation (Revisited)

• Main Authors: Bruce A. Leybourne, Michael B. Adams
• Format: Article
• Language: English
• Published: International Institute of Informatics and Cybernetics 2020-08-01
• Series: Journal of Systemics, Cybernetics and Informatics
• Subjects: surge tectonic vortex; banda sea; enso; triple junction; mantle dynamics
• Online Access: http://www.iiisci.org/Journal/CV$/sci/pdfs/IP093LL20.pdf

The upwelling mantle within the Banda Sea is modeled using computer visualization techniques. The Banda Sea is considered a triple junction of the Pacific, Australian, and Eurasian Plates within the plate tectonic hypothesis. Evaluation of mantle depths from gravity and seismic studies indicates upwelling of mantle from approximately 30-40 km under the continental shelf of Australia to 21 km in the Banda Arc. From here the mantle rises to 14 km within the Weber Deep and finally reaches a depth of 7 km in the North Banda Sea. Seismic epicenter data delineate spatial boundaries of flow regimes and define magmatic migration routes. Epicenter magnitudes are visualized in 3 dimensions by color-coding. Topographic and bathymetric data from in-house sources define geographic position and geomorphology of the model domain, while altimetry data delineate the gravity field associated with a component of mantle dynamics using contour lines or interpolated color fields. Conceptual animation portrays upwelling and divergence of mantle flow structures (geostreams) underlying the tectonic trends of the region and the resulting counterflow within the volcanic arcs based on the surge tectonic hypothesis. This animation uses a series of color-coded arrows and particle systems to represent these flow structures in motion. Induced micro-gravity oscillations in the triple junction may be caused by planetary gravity waves. This phenomenon is explored to determine the coupling effects with the atmospheric pressure flux of the southern oscillation, which modulates El Nino.