EU Regional School with Dr. Leonardo Uida, Ph.D.

Tuesday, December 15, 2020, 11:00am

 

Dr. Leonardo Uida, Ph.D. – Geophysical Forward and Inverse Modeling

Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, UK

Abstract

Inverse problems abound in geophysics. It is the primary way in which we investigate the subsurface of the Earth, which is largely inaccessible to us beyond the first dozen or so kilometers. From measurements acquired on land, sea, air, and from space, geophysicists tease out the inner structure of the Earth – from a few meters to thousands of kilometers deep in the inner core. Observations of disturbances in the Earth’s gravity field are one of the key elements used by geophysicists to investigate the crust-mantle interface, the large-scale structure of sedimentary basins (which are reservoirs for water and hydrocarbons), and even the mass balance of the world’s ice sheets. However, the gravity inverse problem is particularly challenging due to the physics of potential fields. Unique solutions are difficult to come by and only exist under strict assumptions, which often don’t hold for real world scenarios. For these problems, regularization plays a critical role and has been the focus of much research in the past 20 years.

In this tutorial, we will work together to solve a 2D gravity inverse problem in Python. Our code will estimate the shape of a sedimentary basin from gravity observations. This non-linear inverse problem will allow us to visually explore the effects of different types of regularization from a geometric perspective (smoothness, equality constraints, and more). We will discuss the challenges involved in real world applications and the difficulties of quantifying the uncertainty in the solutions. The main goal of this tutorial is to impart theoretical and practical skills that can be easily transferred to other domains.

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