Tainan Neotectonics from Persistent Scatterer Interferometry (sw Taiwan)

Jyr-Ching Hu(1) , Benedicte Fruneau(2) , Benoit Deffontaines(2) , Erwan Pathier(3) , Alain Arnaud(4) , Chyi-Tyi Lee(5) , and Jacques Angelier(6)

(1) National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwa, 106, Taiwan
(2) Université de Marne-la-Vallée, 5 Boulevard Descartes, 77454 Marne-la-Vallée, 77454, France
(3) University of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom, Oxford, United Kingdom
(4) Altamira INFORMATION, Roger de Llúria, 50, àtic B, E-08009 Barcelona, E-08009 Barcelona, Spain
(5) National Central University, No.300, Jung-da Road, Chung-li, Tao-yuan, Taiwan , Tao-yuan 320, Taiwan
(6) Observatoire Océanologique de Villefranche , La Darse BP 48 -, 06235 Villefranche sur Mer , France

Abstract

Hu J.C.1, Fruneau B.2, Deffontaines B. 2, Pathier E.3, Arnaud A. 4, Lee C.T. 5, Angelier J. 6

1. Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan. E-mail : jchu@ntu.edu.tw 2. Université de Marne-la-Vallée, Laboratoire de Géomatériaux et Géologie de l'Ingénieur, 5 Boulevard Descartes, 77454 Marne-la-Vallée, France. E-mail : benoit.deffontaines@univ-mlv.fr. 3 Department of Earth Sciences, Parks Road, Oxford, OX1 3PR,United Kingdom, email : Erwan.Pathier@earth.ox.ac.uk 4. Altamira INFORMATION, C/ Roger de Llúria, 50, àtic B, E-08009 Barcelona, Spain, E-mail : alain.arnaud@altamira-information.com 5. Institute of Applied Geology, National Central University, Chungli, 32054, Taiwan, R.O.C., e-mail: ct@gis.geo.ncu.edu.tw 6. Observatoire Océanologique de Villefranche, Géosciences Azur, Villefranche-sur-Mer, France, E-mail: angelier@geoazur.obs-vlfr.fr

The island of Taiwan, where collision and mountain building occur, provides key examples for analyzing tectonic displacements through Interferometric methods. For instance differential interferograms (InSAR) deduced from 1993-2000 time period were processed in the SW part of Taiwan. Combined with classical geological methods such as studies in the fields (structural, microtectonics, morphostructural methods) applied on the Tainan area (SW Taiwan), situated within a compressive environment, it reveals part of the deformation field of an active elongated anticline close to the deformation front (Deffontaines et al., 1997; Fruneau et al, 2001; Pathier, 2004). Analysis of GPS compaign data set form 1999 to 2003, together with the data of eight continuous GPS data in the surrounding area, indicates a horizontal movement of 12±4 mm/yr in the direction of N44oW for the Tainan Tableland with respect to west coast. Furthermore five precise leveling surveys across Tainan Tableland over a period of tmic hazard assessment is crucial. The new Persistent Scatterers Interferometry method is herein applied in order to better understand deformations through time. This allows to know the deformations of thousands points through recent time and then better map the deformation field due to the active tectonics. Our field knowledge combined with the presence of one fixed GPS station lead us to precisely know the 3D deformation of the area. The latter give knew insights for its geodynamic understanding and the associated sismic hazards for the 2.4 millions inhabitants of the Tainan county.

 

 

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