Spatial Variations of Slip and Creep Rates Along the Southern and Central Dead Sea Fault and the Carmel–Gilboa Fault System

Abstract

Crustal deformation and seismic activity in the Levant is mainly related to the interplate Dead Sea Fault (DSF) and the intraplate Carmel–Gilboa Fault System (CGFS). In this study, we analyze the interseismic deformation along these fault systems using 23 years of Global Positioning System (GPS) measurements obtained from 209 campaign and 60 continuous stations. This GPS data set is the longest record and the densest data set for the DSF, the CGFS, and the Levant region. We use this data set to investigate the spatial variations of slip and creep rates along the southern and central sections of the DSF and the CGFS. Our inversion model results indicate that part of the tectonic motion is transferred from the DSF to the CGFS. We find that the left‐lateral strike‐slip motion along the DSF decreases in a rate of 0.9 ± 0.4 mm/year, from 4.8 ± 0.3 mm/year south to the intersection with the CGFS to 3.9 ± 0.4 mm/year north to this intersection. Along the CGFS, the left‐lateral strike‐slip motion ranges between ∼0.3 and 0.5 mm/year and the extension rate between ∼0.6 and 0.7 mm/year, indicating a total slip rate vector of 0.8 ± 0.4 mm/year in the DSF direction, in agreement with the reduction of slip rate along the DSF near the intersection with the CGFS. Shallow creep is found along the southern and central sections of the Dead Sea basin and the northern Jordan Valley section of the DSF, with creep rates of 3.4 ± 0.4 and 2.3 ± 0.4 mm/year, respectively. These creeping sections were identified as areas with thick Halite layers at the shallow subsurface. We suggest that shallow creep behavior along the DSF is govern by the presence and mechanical properties of the Halite, which probably allows plastic deformation and the transition to velocity strengthening at the shallow subsurface and promotes creep.

Transient Behavior and Interplay Between Seismic and Aseismic Deformation Near the Tip of a Creeping Segment: Insights From the Northern Jordan Valley Segment of the Dead Sea Fault

“…Before 2013 and after 2018, the creep and slip rates are found to be similar, with a creep rate of 2.6 ± 0.3 mm/yr and a total slip rate of 4.0 ± 0.4 mm/yr, comparable to the results reported by Hamiel et al. (2016) and Hamiel and Piatibratova (2021). Between 2013 and 2018, our best‐fitting model indicates that the fault is locked, with a similar total slip rate of 4.0 ± 0.4 mm/yr to the total rate during the creeping periods.…”

“…The third explanation was recently discussed by Barnea Cohen et al (2022). This study followed the studies of Hamiel et al (2016) and Hamiel and Piatibratova (2021), which found that the northern Jordan Valley segment of the DSF is creeping at shallow depths, and suggested that the shallow creep induces shallow seismic activity beneath the northern part of the Sea of Galilee. Barnea Cohen et al ( 2022) used seismic data and showed that the earthquake distribution and focal mechanism suggest shallow NW-SE normal faults splaying from the tip of the creeping segment.…”

“…Figure 3 (top) shows a map of the linear velocities of stations relative to the stable Sinai reference frame (Hamiel & Piatibratova, 2021) for the three different periods: before the 2013 seismic sequence, between the 2013 and 2018 seismic sequences, and after the 2018 seismic sequence. Figure 3 (bottom) shows E-W profiles of the fault parallel velocities for these three periods.…”

“…To obtain the local deformation near the DSF, we converted the station velocities from ITRF2014 to a fixed Sinai reference frame. To accomplish this conversion, we used the Euler pole of the Sinai plate with respect to ITRF2014 (Hamiel & Piatibratova, 2021).…”

Seismicity Induced at the Northern Dead Sea Transform Fault, Kinneret (Sea of Galilee) Basin, by Shallow Creep Involving a Salt Body

“…After presenting the proposal, we test the hypothesis and finally discuss previous mechanisms that have been proposed. Recent geodetic measurements across the Jordan Valley Fault, on a southern tangent of Lake Kinneret, indicate lateral creep of 2.5 ± 0.8 mm/year from the surface down to a depth of 1.5 ± 1.0 km, over a approximately 40 km distance (Hamiel et al., 2016; Hamiel & Piatibratova, 2021). A factor promoting slow slip could be a buried salt layer, as suggested for the Jordan Valley Fault by Hamiel et al.…”