Real‐time high‐rate co‐seismic displacement from ambiguity‐fixed precise point positioning: Application to earthquake early warning

Nowadays more and more high‐rate real‐time GPS data become available that provide a great opportunity to contribute to earthquake early warning (EEW) system in terms of capturing regional surface displacements, as an independent information source, useful for promptly estimating the magnitude of large destructive earthquake. In our study, we demonstrate the performance of the real‐time ambiguity‐fixed precise point positioning (PPP) approach using 5 Hz GPS data collected during El Mayor‐Cucapah earthquake (Mw7.2, 4 April 2010). The PPP‐based displacements show to agree with accelerometer‐based displacement at centimeter level. The key for successfully obtaining high precision displacements is the efficient ambiguity resolution. PPP with ambiguity fixing can result in correct permanent co‐seismic offsets and correct recovery of moment magnitude and fault slip inversion at levels comparable to post‐processing. Integer ambiguity fixing improve real‐time PPP displacementsDisplacements from PPP and accelerometers, displayed a high agreementreal‐time PPP can become complementary to seismic EEW methods