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An Mw 7.8 earthquake occurred on the East Anatolian Fault (EAF) and the secondary Narlı Fault (NF) on Feb 6, 2023, closely followed by an Mw 7.5 event on the Sürgü Fault 9 hours later. We analyze the distant and local seismic data, high-rate GPS recordings, and radar satellite images by Slowness Enhanced Back-Projection and joint Finite Fault Inversion for the Mw 7.8 event to resolve its rupture process. The rupture first initiates and propagates on the NF. After reaching the junction with the EAF, it propagates bilaterally on the EAF, extending 120 km to the northeast at 3.05 km/s and 200 km to the southwest at 3.11 km/s. The southwest speed is further verified by local seismic recordings and the absence of Mach surface wave characteristics. Compared with the EAF, the NF features denser seismic activity in recent decades, suggesting that it was more favorable for rupture nucleation. The EAF segments where the largest coseismic slip occurred have been relatively quiescent since the late 1800s. But the coseismic slip is much larger than the slip deficit accumulated during this period, which could be attributed to an ~900-year supercycle. The EAF geometry is similar to other active fault systems, such as the San Andreas Fault (SAF) and San Jacinto Fault (SJF). Considering high slip rates, resemblant supercycle mode, and the lack of large earthquakes on the southern SAF and SJF since 1857, an M8 earthquake could potentially occur there if most moment accumulation is released at once.

BP is the folder for Back-Projection, with the results and movies for Australia, Europe, and Alaska in. FFI is the folder for the slip model inverted by joint finite fault inversion.

Here, we present an enhanced algorithm to correct interferometric synthetic aperture radar (InSAR) phase unwrapping errors by incorporating iterative spatial bridging between islands and phase closure among interferograms. We use rapid repeat airborne synthetic aperture radar acquisitions from NASA’s airborne uninhabited aerial vehicle synthetic aperture radar (UAVSAR) instrument to estimate short-term changes in water level within coastal wetlands from a stack of consecutive interferograms acquired with very short temporal separation (~30 min). The algorithm is applied to six consecutive UAVSAR images collected in tidal wetlands of the Wax Lake Delta, Louisiana, USA. Validation of our water level change retrievals with in situ field observations was conclusive with high correlation and an RMSE generally smaller than 3 cm. Comparison of our algorithm with other phase unwrapping error correction methods shows significant improvement (30%–35% increase in the number of correctly unwrapped pixels) when applied to rapid changes in water level. The set of corrections presented in this work enables measurement of water level change in deltas and other areas where tides drive highly dynamic flooding of inland vegetated areas. Although demonstrated for water level change, the method is applicable to other InSAR datasets with large spatial gradients or observed discontinuities between coherent but spatially isolated areas.

Additional file 1: Table S1. The information of involved variables. Table S2. Predictor selection. Table S3. Comparison between included and excluded data. Figure S1. Bayesian Network model based on all predictors. Figure S2. Tenfold ten-cross validation.

AT099_AZ: azimuth offsets of ascending 99,acquired byspeckle tracking AT099_IFG: InSAR of ascending 99 AT099_RG: range offsets of ascending 99, acquired byspeckle tracking DT106_AZ: azimuth offsets of descending 106,acquired byspeckle tracking DT106_IFG: InSAR of descending 106 DT106_RG: range offsets of descending 106,acquired byspeckle tracking The full-resolution data is stored in the "merge" folder under each directory. The downsampled data is named "resampled.txt".The format is: Longitude Latitude Amplitude(in cm)Vz Vn Ve Weight Weight. #(Vz, Vn, Ve) denotes the direction of Line of Sight. Two weights are identical.

Time series analysis of synthetic aperture radar (SAR) and interferometric SAR generally starts with coregistration for the precise alignment of the stack of images. Here we introduce a model-adjusted geometrical image coregistration (MAGIC) algorithm for stack coregistration. This algorithm corrects for atmospheric propagation delays and known surface motions using existing models and ensures simplicity and computational efficiency in the data processing systems. We validate this approach by evaluating the impact of different geolocation errors on stacks of C-band Sentinel-1 and L-band ALOS-2 data, with a focus on the ionosphere. Our results show that the impact of the ionosphere dominates Sentinel-1 ascending (dusk-side) orbit and ALOS-2 data. After correcting for ionosphere using the JPL high resolution global ionospheric maps, with topside total electron content (TEC) estimated from GPS receivers onboard the Sentinel-1 platforms, solid Earth tides, and troposphere, the mis-registration RMSE reduces by over a factor of four from 0.20 m to 0.05 m for Sentinel-1 and from 2.66 m to 0.56 m for ALOS-2. The results demonstrate that for Sentinel-1, the MAGIC approach is accurate enough in the range direction for most applications including interferometry; while for the L-band SAR, it can be potentially accurate enough if topside TEC is available. Based on our current understanding of different error sources, we evaluate the expected range geolocation error budget for the upcoming NISAR mission with an upper bound of the relative geolocation error of 1.3 m and 0.2 m for its L- and S-band SAR, respectively.

The steering knuckle is the important safety part of commercial vehicle, the structure is more complex as the performance improved. In this paper, a kind of disc-type steering knuckle with complexity up to level S4 is studied, and a precision forging process is proposed to change the traditional horizontal open pre-forging and large flash final forging into semi-closed flat thin flash pre-forging and semi-closed flat thin flash final forging. Based on the analysis of mechanism and effect of the classical forming theory on the flat thin flash, the equivalent stress, equivalent strain and temperature distribution field as well as the force formation curve and deformation law are obtained by means of thermal-mechanical coupled finite element simulation analysis, and the correctness of the process scheme is verified. The precision forging of steering knuckle has been successfully developed on the program controlled hammer and CNC electric screw press, the results are consistent with the simulation results. The material utilization rate of the new process is 88%, which is 16% higher than that of the traditional process, with better quality and stronger bearing capacity. In recent years, the company has built four automatic production lines with CNC electric screw press as main equipment, with robot operation and online detection of hot forging, it has realized mass production of flat thin flash precision forging of A161 disc-type knuckle series product.

To improve the oil recovery and economic efficiency in heavy oil reservoirs in late steam flooding, taking J6 Block of Xinjiang Oilfield as the research object, 3D physical modeling experiments of steam flooding, CO2-foam assisted steam flooding, and CO2 assisted steam flooding under different perforation conditions are conducted, and CO2-assisted steam flooding is proposed for reservoirs in the late stage of steam flooding. The experimental results show that after adjusting the perforation in late steam flooding, the CO2 assisted steam flooding formed a lateral expansion of the steam chamber in the middle and lower parts of the injection well and a development mode for the production of overriding gravity oil drainage in the top chamber of the production well; high temperature water, oil, and CO2 formed stable low-viscosity quasi-single-phase emulsified fluid; and CO2 acted as a thermal insulation in the steam chamber at the top, reduced the steam partial pressure inside the steam chamber, and effectively improved the heat efficiency of injected steam. Based on the three-dimensional physical experiments and the developed situation of the J6 block in Xinjiang Oilfield, the CO2 assisted steam flooding for the J6 block was designed. The application showed that the CO2 assisted steam flooding made the oil vapor ratio increase from 0.12 to 0.16 by 34.0%, the oil recovery increase from 16.1% to 21.5%, and the final oil recovery goes up to 66.5% compared to steam flooding after perforation adjustment. Key words: heavy oil reservoir, three-dimensional physical simulation experiment, steam flooding, CO2 assisted steam flooding, steam chamber, steam (CO2) chamber overriding gravity drainage

We present deformation measurements of the Kirishima volcanic complex from ALOS and ALOS-2 Interferometric Synthetic Aperture Radar (InSAR) time series during 2006–2019. Shinmoe-dake deflated ∼6 cm during the 2008–2010 phreatic eruptions and inflated ∼5 cm prior to the 2017 magmatic eruption. Iwo-yama inflated ∼19 cm within the crater since January 2015 and ∼7 cm around the southern and western vents since 4 months before the 2018 eruption. These deformations can be modeled as ellipsoids at ∼700 m depth beneath Shinmoe-dake and as a sphere on top of an ellipsoid at ∼130 and ∼340 m depths beneath Iwo-yama. Combining geodetic, geoelectric, geochemical, and petrological analysis, we interpret the hydrothermal origin of the deflation at Shinmoe-dake and inflation at Iwo-yama; the hydrothermal–magmatic transition during the 2011 Shinmoe-dake eruption; and water-boiling and bottom-up pressurization as driving mechanisms of the inflation at Iwo-yama. The study highlights the imaging potential of InSAR time series on complex hydrothermal systems.