Observation of Non-Linear Urban Ground Motion in Manila (Philippines) between 1993 and 2010 using InSAR Techniques
Raucoules, Daniel¹; Le Cozannet, Gonéri¹; Daag, Arturo²; Gravelle, Médéric³; Woppelmann, Guy^3
1BRGM, FRANCE; ²Philvocs, PHILIPPINES; ³Université de La Rochelle, LIENSs, FRANCE

This poster shows the application of Differential SAR Interferometry (DInSAR) for monitoring variable ground urban motion (uplift and subsidence) over long periods taking place in Manila (The Philippines). Considering the high deformations rates expected on the area (10-15 cm/yr of maximum deformation) and the fact that we work on a urbanized cover, we use conventional DInSAR with an adapted stacking procedure. The objective is to produce surface deformation rate maps at different periods in order to represent the spatio-temporal evolution of the phenomena. The origin of the surface motion is discussed based on ground based observations. In addition, the ground motions are affecting several geodetic instrument, including a tide gauge with sea level records back to 1902, permanent GPS stations and DORIS instrument. A significant implication of these ground motions is therefore to alter the possibility to use these time series for refining knowledge of sea level rise and variations during the XXth century.

Line Of Sight displacement rate in rad/yr for the whole 2003-2010 period (EnviSat/ASAR data). black contour separation: 5 rad/yr