Estimating Euler pole parameters for Sundaland block in IGB14 using robust filtration approach

Enhancing the accuracy of the Euler pole parameters for the Sundaland block is essential, given the revised reference frame. The selection of GNSS stations should be obtained before the major event of the 2004 Mw9.2 Sumatra-Andaman earthquake. Initially, 34 GNSS stations in Malaysia, Thailand, Singapore, Indonesia, and Philippines (1999–2004) were adopted under the International Terrestrial Reference Frame 2014 (ITRF2014), specifically IGB14. This study employed precise point positioning (PPP) to obtain accurate coordinates via scientific GipsyX version 1.7. The coordinate time series derived from the X-file mapping approach was utilised to estimate a linear trend motion. The stations’ velocities were derived using a 3-dimensional (3D) linear regression approach. To achieve an optimal Euler pole parameter, the outlier filtration processes were employed using statistical tests, limit-based test, and combined statistical and limit-based tests. The combined Baarda and limit-based method was clarified as the robust filtration approach to derive the optimal Euler pole parameters for the Sundaland block at the latitude of 66.77° and longitude of –100.34°, with a rotation rate of 0.302±0.007°/Myr. A further study with densified data covering the maximum Sundaland region is expected to derive the Euler pole parameters more accurately.