[Society of Exploration Geophysicists and and Chinese Geophysical Society International Workshop and Gravity, Electrical & Magnetic Methods and their Applications, Chenghu, China, 19-22 April 2015 - Chenghu, China (19 April to 22 April)] International Workshop and Gravity, Electrical & Magnetic Methods and their Applications, Chenghu, China, 19-22 April 2015 - Computation of the vector gravity field due to 3D bodies by the finite element method