Our understanding of plate boundary deformation has been enhanced by transient signals observed against the backdrop of time-independent secular motions. We make use of a new analysis of displacement time series from about 1,000 continuous Global Positioning System (GPS) stations in California from 1999 to 2018 to distinguish tectonic and nontectonic transients from secular motion. A primary objective is to define a high-resolution three-dimensional reference frame (datum) for California that can be rapidly maintained with geodetic data to accommodate both secular and time-dependent motions. To this end, we compare the displacements to those predicted by a horizontal secular fault slip model for the region and construct displacement and strain rate fields. Over the past 19 years, California has experienced 19 geodetically detectable earthquakes and widespread postseismic deformation. We observe postseismic strain rate variations as large as 1,000 nstrain/year with moment releases equivalent up to an Mw6.8 earthquake. We find significant secular differences up to 10 mm/year with the fault slip model, from the Mendocino Triple Junction to the southern Cascadia subduction zone, the northern Basin and Range, and the Santa Barbara channel. Secular vertical uplift is observed across the Transverse Ranges, Coastal Ranges, Sierra Nevada, as well as large-scale postseismic uplift after the 1999 Mw7.1 Hector Mine and 2010 Mw7.2 El Mayor-Cucapah earthquakes. We also identify areas of vertical land motions due to anthropogenic, natural, and magmatic processes. Finally, we demonstrate the utility of the kinematic datum by improving the accuracy of high-spatial-resolution 12-day repeat-cycle Sentinel-1 Interferometric Synthetic Aperture Radar displacement and velocity maps.

6Considerable three-dimensional (3D) effects are involved in the seismic performance of pile-7 supported wharves. Such effects include the pile-to-pile interaction mechanisms as dictated by 8 the behavior of the surrounding soil. This interaction might be further affected by potential 9 ground slope settlement/heave, and the constraint of pile connectivity along the relatively rigid 10 wharf deck. In order to capture a number of these salient response characteristics, a 3D finite 11 element (FE) study is conducted herein. The prototype system motivating this study is presented, 12 along with the corresponding numerical details. A realistic multi-layer soil profile is considered, 13 with interbedded relatively soft/stiff strata. Effect of the resulting seismically-induced ground 14 deformation on the pile-supported wharf system is explored. Specific attention is drawn to the 15 noteworthy potential changes in axial force due to variation in pile embedment depth, and the 16 ground slope deformation. The analysis technique as well as the derived insights are of 17 significance to general pile-wharf-ground system configurations. 18 19 Arulmoli et al. (2004) carried out a 2D dynamic finite element (FE) DYNAFLOW analysis of a 43 wharf-dike-backland system, investigating the pile pinning effects. Using OpenSees, Yang et al. 44 (2012) conducted 2D FE simulations to develop fragility curves for a typical wharf structure. 45 Employing advanced structural and soil modeling procedures, Shafieezadeh et al. (2012a) 46 performed 2D nonlinear plane-strain seismic analyses. The simulated results showed that the 47

We installed 10 continuous Global Positioning System (GPS) stations on the northeast margin of the Tibetan Plateau at the end of 2012, in order to qualitatively investigate strain accumulation across the Liupanshan Fault (LPSF). We integrated our newly built stations with 48 other existing GPS stations to provide new insights into three-dimensional tectonic deformation. We employed white plus flicker noise model as a statistical model to obtain realistic velocities and corresponding uncertainties in the ITRF2014 and Ordos-fixed reference frame. The total velocity decrease from northwest to southeast in the Longxi Block (LXB) was 5.3 mm/yr within the range of 200 km west of the LPSF on the horizontal component. The first-order characteristic of the vertical crustal deformation was uplift for the northeastern margin of the Tibetan Plateau. The uplift rates in the LXB and the Ordos Block (ORB) were 1.0 and 2.0 mm/yr, respectively. We adopted an improved spherical wavelet algorithm to invert for multiscale strain rates and rotation rates. Multiscale strain rates showed a complex crustal deformation pattern. A significant clockwise rotation of about 30 nradians/yr (10−9 radians/year) was identified around the Dingxi. Localized strain accumulation was determined around the intersectional region between the Haiyuan Fault (HYF) and the LPSF. The deformation pattern across the LFPS was similar to that of the Longmengshan Fault (LMSF) before the 2008 Wenchuan MS 8.0 earthquake. Furthermore, according to the distributed second invariant of strain rates at different spatial scale, strain partitioning has already spatially localized along the Xiaokou–Liupanshan–Longxian–Baoji fault belt (XLLBF). The tectonic deformation and localized strain buildup together with seismicity imply a high probability for a potential earthquake in this zone.