VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm

Autor(es)

Bortolozo, Cassiano Antonio ^[1] ; Porsani, Jorge Luis ^[1] ; Monteiro dos Santos, Fernando Acacio ^[2] ; Almeida, Emerson Rodrigo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfert JAG, Dept Geofis, BR-05508090 Sao Paulo - Brazil

^[2] Univ Lisbon, Fac Ciencias, IDL, P-1749016 Lisbon - Portugal

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED GEOPHYSICS; v. 112, p. 157-174, JAN 2015.
• Citações Web of Science: 8

Resumo

Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Parana sedimentary basin (Bebedouro and Pirassununga cities), both located in Sao Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/08466-3 - Caracterização geoelétrica de aquíferos fraturados em basaltos na região de Bebedouro, SP, por meio de inversão conjunta de SEVs e sondagens TDEM
• Beneficiário: Jorge Luís Porsani
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/15338-4 - Mapeamento de aquíferos fraturados em basaltos da Formação Serra Geral na região noroeste do estado de São Paulo, através de inversão conjunta 1D e 2D de dados de eletrorresistividade (SEV e CE) e sondagens eletromagnéticas no domínio do tempo (TDEM)
• Beneficiário: Jorge Luís Porsani
• Modalidade de apoio: Auxílio à Pesquisa - Regular