Gravity Modeling with Vertical Line Elements

Tuesday, August 25, 2015
Jefferson C Chang, University of Oklahoma, Geology & Geophysics, Norman, OK, United States; Oklahoma Geological Survey, Norman, OK, United States and Kevin Crain, Univ of OK-Geology & Geophysic, Oklahoma Geological Survey, Norman, OK, United States
Abstract:
At the heart of modeling gravity data is the accountability of mass between the observation point, and the Earth’s center; thus, gravity modeling is strongly sensitive to elevation, i.e., gridded topography or digital elevation models (DEMs). We have developed an algorithm that allows (1) fast and accurate computations from ungridded point data gravity, (2) stable gravity modeling of stations that are within a modeled body, and (3) fast calculations of six-component gradiometry. One of the applications of this algorithm is when working with gravity data that were collected at differing elevations from the surface, e.g., merging land-based surveys with airborne surveys; we are able to model the data, without having to apply filters and/or gridding algorithms that may introduce unobserved anomalies. Another application is when modeling underground gravity data (e.g., in a mine, or a borehole), where this algorithm does not require any tedious manipulation of the model to avoid mathematical singularities.