Vertical Displacement Rate Field of Taiwan From Geodetic Levelling Data 2000-2008

Abstract We have developed the most precise vertical displacement rate field of Taiwan Island to date from four sets of precise geodetic levelling data between 2000 and 2008. More than 4000 km of levelling lines between solidly constructed benchmarks were repeatedly surveyed by 1st-order levelling. Strict specifications for field work procedures and comprehensive corrections for systemic errors were applied to the levelling data. Furthermore, in order to account for the vertical deformations caused by four major earthquakes during the data span, coseismic offset corrections were computed and applied. The adjusted orthometric heights and vertical displacement rates of the benchmarks were obtained by least-squares estimation (LSE). The estimated standard deviations of the vertical rates are in the range of ± 0.41 mm/yr and ± 2.47 mm/yr, with a mean value of ± 1.64 mm/yr. These highly accurate results reveal that the most significant subsidence rate is observed in SW Taiwan at -109.4 mm/yr. Land uplift is widely observed in the Central Range and the Coastal Range, with the largest uplift rate of +29.4 mm/yr in SE Taiwan, at the convergence boundary of the Philippine Sea and the Eurasian plates.

[1]  R. Rau,et al.  Crustal deformation and block kinematics in transition from collision to subduction: Global positioning system measurements in northern Taiwan, 1995–2005 , 2008 .

[2]  Geodetically observed surface displacements of the 1999 Chi-Chi, Taiwan, Earthquake , 2000 .

[3]  R. Rau,et al.  Contemporary deformation of tectonic escape in SW Taiwan from GPS observations, 1995–2005 , 2007 .

[4]  Liu Chi-Ching,et al.  Vertical crustal movements in eastern Taiwan and their tectonic implications , 1990 .

[5]  T. J. Kukkamaki.  Uber die Nivellitische Refraktion , 1939 .

[6]  P. M. De Martini,et al.  Short-term vertical velocity field in the Apennines (Italy) revealed by geodetic levelling data , 2006 .

[7]  Emma Suriñach,et al.  RECENT VERTICAL MOVEMENTS FROM HIGH-PRECISION LEVELING DATA IN NORTHEAST SPAIN , 1996 .

[8]  A. Schlatter,et al.  Recent vertical movements from precise levelling in the vicinity of the city of Basel, Switzerland , 2005 .

[9]  H. Chen,et al.  Global Positioning System Measurements of Crustal Deformation in the Taiwan Arc-Continent Collision Zone , 1994 .

[10]  Ian Parsons,et al.  Surface deformation due to shear and tensile faults in a half-space , 1986 .

[11]  Kwo-Hwa Chen,et al.  A NEW HEIGHT REFERENCE NETWORK IN TAIWAN , 2003 .

[12]  M. A. R. Cooper.  Modern theodolites and levels , 1982 .

[13]  Shui-Beih Yu,et al.  Coseismic Movement and Seismic Ground Motion Associated with the 31 March 2002 off Hualien, Taiwan, Earthquake , 2004 .

[14]  J. Mäkinen,et al.  Determination of post-glacial land uplift from the three precise levellings in Finland , 1998 .

[15]  R. Rau,et al.  Crustal deformation and block kinematics in transition from collision to 1 subduction : GPS measurements in northern Taiwan , 1995-2005 2 3 4 5 , 2008 .

[16]  Aline Peltier,et al.  Ground deformation patterns at White Island volcano (New Zealand) between 1967 and 2008 deduced from levelling data , 2009 .

[17]  A. Schlatter.  Das neue Landeshöhennetz der Schweiz LHN95 , 2006 .

[18]  R. Rau,et al.  Coseismic source model of the 2003 Mw 6.8 Chengkung earthquake, Taiwan, determined from GPS measurements , 2007 .

[19]  Shui-Beih Yu,et al.  Velocity field of GPS stations in the Taiwan area , 1997 .

[20]  Walter H. F. Smith,et al.  Free software helps map and display data , 1991 .

[21]  Tzay-Chyn Shin,et al.  Coseismic versus interseismic ground deformations, fault rupture inversion and segmentation revealed by 2003 Mw 6.8 Chengkung earthquake in eastern Taiwan , 2006 .

[22]  J. Angelier,et al.  Variations along the strike of the Taiwan thrust belt: Basement control on structural style, wedge geometry, and kinematics , 2002 .

[23]  Y. Okada.  Surface deformation due to shear and tensile faults in a half-space , 1985 .

[24]  Schweizerische Geodätische Kommission.  Geodätisch-Geophysikalische Arbeiten in der Schweiz , 1982 .