Kinematics of deformation across the Philippine Archipelago as observed from GPS campaign data

More than 150 Global Positioning System (GPS) points across the Philippine archipelago have been installed by the Philippine Institute of Volcanology and Seismology (PHIVOLCS) and its collaborative partners. Results from the repeated GPS measurements conducted since 1996 up to the present on these points showed the following: (1) Based on uniform motion and velocity directions gathered from the GPS data, the Philippine Mobile Belt can generally be subdivided into three blocks: Central to Northern Luzon; Southern Luzon to Southern Visayas; Mindanao; (2) There is a significant internal deformation in the Philippine Mobile Belt as seen from variable velocities and azimuth directions relative to Eurasian plate. (3) Relative velocities across the Philippine Fault vary from 20 mm/yr to 29 mm/yr (vector azimuths from 322 deg to 4 deg) in Northern Luzon; 31.2 mm/yr to 53.3 mm/yr (300 deg to 310 deg) in Southern Luzon; 20.5 mm/yr to 25.1 mm/yr (305 deg to 347 deg) in Visayas and 14 mm/yr to 33 mm/yr (338 deg to 40 deg) in Mindanao. (4) There is an active extensional deformation (18 mm/yr) in Macolod Corridor while compressional deformation (24 mm/yr) exists between Southern Visayas and Mindanao. This reverse analogue of deformation is probably the result of the collision between Palawan and the Philippine Mobile Belt.