INVESTIGATING STRESS INTERACTIONS BETWEEN MAJOR BORDER FAULTS AND MAGMATIC SOURCES IN THE NATRON RIFT, TANZANIA Abstract

abstract

  • Previous studies on the East African Rift (EAR) and other regions of youthful continental divergence have shown both tectonic and magmatic forces play a role in the dynamics of rift initiation. However, the relationship between these forces and their influence on strain accumulation and accommodation during continental rifting is still under investigation. In particular, the physics of volcano-tectonic interactions during continental rifting remains debated largely due to a lack of precision observations in a proper setting. This project aims to elucidate volcano-tectonic interactions at selected faults and magmatic sources in the nascent Natron Rift, Tanzania that are in close proximity to the Ol Doinyo Lengai volcano. In our preliminary work we test the effects of static stress changes due to recent tectonomagmatic events spanning 2007-2010 using Coulomb 3.4. This work builds upon previous studies by including an Ol Doinyo Lengai magma chamber modeled as a Mogi source. Our preliminary work confirms that the 2007 Gelai diking event and coincident deflation of the Gelai magma chamber increases the Coulomb stresses on the western border fault of the Natron Rift and surroundings near Ol Doinyo Lengai. We plan to (1) measure surface displacements of the focus site with 9 new GNSS/GPS sites and (2) test a suite of tectonomagmatic interactions with numerical models, of which predicted surface displacements can be compared with new observations. We expect results from this study will provide new insights into the interactions of faults and magmatic sources during young continental rifting.

publication date

  • 2016

presented at event