Discipline: Ecology, Environmental & Earth Sciences
Subcategory: STEM Research
Azucena Zamora - University of Texas at El Paso
Co-Author(s): Anibal Sosa, Universidad ICESI; Cali, Colombia; Aaron A. Velasco, University of Texas at El Paso; Texas, USA; Chengping Chai, Oak Ridge National Laboratory;Tennessee, USA; Monica Maceira, Oak Ridge National Laboratory, Tennessee, USA
Studying the tectonic evolution of the Earth and its constant motion allows us to characterize, using geophysical surveys and analysis, the location of seismological faults in the lower crust and determine the possible hazards associated with them. We develop and use a novel approach to include physical constraints into the nonlinear joint inversion problem to determine crust and upper mantle structure. Previous studies have shown that combining surface wave group velocities and Bouguer gravity anomalies can help identify key features within the complex subsurface that may be overlooked by the individual geophysical surveys. Our approach enhances numerical aspects of geophysical inversion since it seems to introduce a regularization effect over the models; that avoids the expensive search for the so-called regularization parameters. Regularization or smoothing parameters act as the key part for convergence of inversion algorithms. Our primal-dual formulation of the inverse problem allows the inclusion of appropriate a priori information, that narrows the model space region of crust and upper mantle structure. We apply our approach using high quality disparate data sets recorded from the enhanced seismic network of Colombia and the gravity recovery and climate experiment (GRACE) Earth Gravity Model-2008 (EGM2008), aiming to shed light on some of the controversies related to the complex interactions of three major tectonic plates beneath Colombia. We expect not only to improve current state-of-the-art modeling of Colombia’s Earth structure, but also to offer a creative approach to more accurate inverse modeling with an efficient solution for the non-linear inverse problems for Earth structure.
Funder Acknowledgement(s): National Science Foundation-Centers of Research Excellence in Science and Technology (NSF CREST) Postdoctoral Research Fellowship. Fulbright Scholar Program
Faculty Advisor: None Listed,
NSF Affiliation: CREST