New approach to detect seismic surface waves in 1Hz-sampled GPS time series

Abstract

Recently, co-seismic seismic source characterization based on GPS measurements has been completed in near- and far-field with remarkable results. However, the accuracy of the ground displacement measurement inferred from GPS phase residuals is still depending of the distribution of satellites in the sky. We test here a method, based on the double difference (DD) computations of Line of Sight (LOS), that allows detecting 3D co-seismic ground shaking. The DD method is a quasi-analytically free of most of intrinsic errors affecting GPS measurements. The seismic waves presented in this study produced DD amplitudes 4 and 7 times stronger than the background noise. The method is benchmarked using the GEONET GPS stations recording the Hokkaido Earthquake (2003 September 25th, Mw = 8.3).

Consistency of PPP GPS and strong-motion records: case study of Mw9.0 Tohoku-Oki 2011 earthquake

“…consistency for horizontals better than vertical component). Again, the reliability of the vertical components of motions appears to be better than the horizontal ones, likely because of the anisotropic distribution of GPS satellites in the sky (Houlié et al, 2011). The correlation of the seismic waves directivity with the consistency of the GPS and strong-motion networks is difficult due to the complexity of the rupture and the two potential sources (Suzuki et al, 2011;Koketsu et al, 2011).…”

The Potential of High‐Rate GPS for Strong Ground Motion Assessment

“…This demonstrates that the 1 Hz sampling frequency (Nyquist frequency of 0.5 Hz or 2 s) is the limiting factor for the period range of observation in this case. Although the Tohoku-Oki event is not covered by our modeling hypotheses, other earthquakes have been well recorded by high-rate GPS (Miyazaki et al, 2004;Bilich et al, 2008;Larson and Miyazaki, 2008;Yokota et al, 2009;Delouis et al, 2010;Shi et al, 2010;Allen and Ziv, 2011;Avallone et al, 2011;Houlié et al, 2011Houlié et al, , 2014Lay et al, 2011;Yue and Lay, 2011;Mitsui and Heki, 2012;Zheng et al, 2012;Kelevitz et al, 2017). A case study is presented in the Observations from the 2008 IwateMiyagi Nairiku Earthquake section.…”

“…Because of the different processing techniques, environmental conditions (including multipathing and troposphere state during experiments), and satellite geometry (Houlié et al, 2011), the noise level for each dataset is different (see Fig. 1).…”

“…1). The Tokachi-Oki dataset is the most accurate and least noisy dataset because it has been processed with a DD approach (Houlié et al, 2011) using final orbit/ clock products. We do not expect to see significant differences in DD mode as implemented in GAMIT, Bernese (Dach et al, 2015), or GIPSY software.…”

“…Häberling et al (2015) showed that beyond this rate, signal autocorrelation could take place. 1 Hz GPS recordings have been used to detect motions of the Earth's surface associated with seismic-wave propagation Houlié et al, 2011;Kaloop and Rabah, 2016), for earthquake early warning (Allen and Ziv, 2011;Bock et al, 2011), to invert for coseismic slip of large (M w > 6) events (Miyazaki et al, 2004;Miyazaki and Larson, 2008;Rhie et al, 2009;Houlié et al, 2014), to constrain seismic moment magnitude (Melgar et al, 2015), and to record the Earth's normal modes (Mitsui and Heki, 2012), or simply coseismic offsets . Psimoulis et al (2014) showed that it is possible to establish maximum ground velocity (MGV) maps at long periods (T > 3 s) using high sampling rate GPS data collected during the 2011 Tohoku-Oki megathrust event.…”