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<p>Aseismic creep is detected and started to be monitored along the 100 km-long Palu-Hazar Segment of the Eastern Anatolian Fault (EAF) in Turkey, a major plate boundary between Anatolia and Arabia. We used creepmeters, InSAR, GPS, and seismic observations to document the extent and magnitude of this motion in order to increase our knowledge on the spatiotemporal variation of creep along the EAF, its relationship with the lithology and tectonic structures, and the stress change on the neighboring fault segments. Until now, we observed the region with continuous GPS and survey GPS measurements with near (~ 0.1- 4 km to the fault) and far-field (~25 – 225 km from the fault) stations to determine the depth of the creep zone and its velocity along the EAF. We processed 6 years (2014 – 2019) of continuous and 7 campaign (2015 – 2019) GPS data with GAMIT/GLOBK software. With elastic models, we determined a creep rate that reaches about 5 ± 0.3 mm/yr from GPS observations (50% of secular velocity). In addition to surface control of the creeping zone, we analyzed the deformations, by using three Terrestrial Laser Scanner (TLS) survey, in the Palu railway tunnel that crosses the fault where the walls of the tunnel have been offset by 15 ± 2 mm since the construction in the middle of the last century. Also, two creepmeters were installed inside the tunnel and transient creep anomalies are detected. These results are correlated with seismic and InSAR data (This study is supported by TUBITAK 1001 projects 114Y250 and 118Y450).</p><p>Keywords: Hazar-Palu, Creep, East Anatolian Fault, Earthquake, GPS, InSAR, TLS</p>

<p>This study aims to estimate vertical land motion (VLM) at tide gauges (TG), located in the Mediterranean, Aegean and the Marmara Sea coasts of Turkey, from differences of multimission satellite altimetry and TG sea level time series. Initially, relative sea level trends are estimated at 7 tide gauges stations operated by the Turkish General Directorate of Mapping over the period 2001-2019. Subsequently, absolute sea level trends independent from VLM are computed from multimission satellite altimetry data over the same period. We have computed estimates of linear trends of difference time series between altimetry and tide gauge sea level after removing seasonal signals by harmonic analysis from each time series to estimate the vertical land motion (VLM) at tide gauges. Traditional way of VLM determination at tide gauges is to use GPS@TG or preferably CGPS@TG data. We therefore, processed these GPS data, collected over the years by several TG-GPS campaigns and by continuous GPS stations close to the TG processed by GAMIT/GLOBK software. Subsequently, the GPS and CGPS vertical coordinate time series are used to estimate VLM. These two different VLM estimates, one from GPS and CGPS coordinate time series and other from altimetry-TG sea level time series differences are compared.</p><p> </p><p><strong>Keywords: Vertical land motion, Sea Level Changes, Tide gauge, Satellite altimetry, GPS, CGPS </strong></p>

<p>January 24, 2020 Sivrice earthquake (Mw 6.8), which is the largest along the East Anatolian Fault (EAF) over the last century, is providing a wealth of information on the mechanics of transform faulting and for monitoring the different phases of the last seismic cycle. In this study, we aim to estimate coseismic and postseismic surface deformation along the Sivrice earthquake rupture and determine the strain accumulations on Pütürge segment by combining InSAR and GNSS measurements. The area was described one of the major seismic gaps along the EAF and we have started to study from Palu to Sivrice segments of the EAF, since 2015. Near field survey GNSS network has been established since 2015 and measured two times in a year, until 2021. Besides, after the earthquake, we surveyed 60% of near field sites to contain the coseismic field within 2-3 days. This dataset analyzed with continuous GNSS stations around the region to control the far field of the deformation field. Additionally, this dataset is densified by InSAR deformation field. For this purpose, the stack of interferograms have been interpreted from descending orbit Sentinel-1 dataset, composed of 6 days interval SAR acquisitions that starts from January 2020 to June 2020 which covers the earthquake time. As a result, significant differences between the pattern of strain accumulation before and after earthquake are documented with both GNSS and InSAR data. Moreover, the signature of the postseismic deformations is presented for 6 months.  </p><p>This study was supported by TUBITAK 1001 project no. 114Y250 and 118Y435.</p><p>Keywords: Sivrice earthquake, EAF, coseismic, postseismic, InSAR, GNSS</p>