Post-Seismic Deformation from the 2009 Mw 6.3 Dachaidan Earthquake in the Northern Qaidam Basin Detected by Small Baseline Subset InSAR Technique

Abstract

On 28 August 2009, one thrust-faulting Mw 6.3 earthquake struck the northern Qaidam basin, China. Due to the lack of ground observations in this remote region, this study presents high-precision and high spatio-temporal resolution post-seismic deformation series with a small baseline subset InSAR technique. At the temporal scale, this changes from fast to slow with time, with a maximum uplift up to 7.4 cm along the line of sight 334 days after the event. At the spatial scale, this is more obvious at the hanging wall than that at the footwall, and decreases from the middle to both sides at the hanging wall. We then propose a method to calculate the correlation coefficient between co-seismic and post-seismic deformation by normalizing them. The correlation coefficient is found to be 0.73, indicating a similar subsurface process occurring during both phases. The results indicate that afterslip may dominate the post-seismic deformation during 19–334 days after the event, which mainly occurs with the fault geometry and depth similar to those of the c-seismic rupturing, and partly extends to the shallower and deeper depths.

Time-Dependent Afterslip of the 2009 Mw 6.3 Dachaidan Earthquake (China) and Viscosity beneath the Qaidam Basin Inferred from Postseismic Deformation Observations

“…In this study, we mainly focus on four items, including (1) improving the method in Diao et al [33] to estimate the time-dependent afterslip distribution and the viscosity simultaneously; (2) modeling the InSAR deformation time series following the 2009 Mw 6.3 DCD earthquake in Liu et al [23]; (3) seeking the dominant mechanisms responsible for postseismic deformation; and (4) finally investigating the viscosity beneath the northern side of the Qaidam Basin.…”

“…Meanwhile, InSAR data has also been confirmed as an alternative observation to investigate the postseismic process due to its high vertical precision and spatial resolution [15,16,[25][26][27][28][29][30][31][32]. Feng [22] and Liu et al [23] have derived the postseismic deformation time series. In this study, we prefer to use the observations from Liu et al [23] because it includes one more SAR image than Feng [22], and has more observations in the near-field region.…”

“…Feng [22] and Liu et al [23] have derived the postseismic deformation time series. In this study, we prefer to use the observations from Liu et al [23] because it includes one more SAR image than Feng [22], and has more observations in the near-field region.…”

“…During the coseismic phase, Interferometric Synthetic Aperture Radar (InSAR) observations of surface deformation and the elastic dislocation model inversion using both uniform and distributed slip models indicated that the 2008 event ruptured the lower half of the brittle seismogenic layer, while the 2009 event ruptured the upper half [1, 3,21]. During the postseismic phase, InSAR deformation time series for the first 334 days after the 2009 event displayed that the postseismic deformation changes from fast to slow with time, and has a similar spatial pattern with the coseismic deformation [22,23]. On the geophysical interpretation of the postseismic deformation, Feng [22] modeled it using the postseismic afterslip model only.…”

Applied Engineering Using Schumann Resonance for Earthquakes Monitoring

“…In the literature there are several types of sensor systems that measure different environmental responses after an earthquake and could determine the material damage caused. An example is the sensor Structural Health Monitoring (SHM), which measures the acceleration of the response movement of a building after an earthquake [29]; other sensors measure post-seismic deformations in horizontal structures [30] or in vertical structures [31].…”