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On February 6, 2023, two large earthquakes occurred near the Turkish town of Kahramanmaraş. The moment magnitude (Mw) 7.8 mainshock ruptured a 310 km-long segment of the left-lateral East Anatolian Fault, propagating through multiple releasing step-overs. The Mw 7.6 aftershock involved nearby left-lateral strike-slip faults of the East Anatolian Fault Zone, causing a 150 km-long rupture. We use remote-sensing observations to constrain the spatial distribution of coseismic slip for these two events and the February 20 Mw 6.4 aftershock near Antakya. Pixel tracking of optical and synthetic aperture radar data of the Sentinel-2 and Sentinel-1 satellites, respectively, provide near-field surface displacements. High-rate Global Navigation Satellite System data constrain each event separately. Coseismic slip extends from the surface to about 15 km depth with a shallow slip deficit. Most aftershocks cluster at major fault bends, surround the regions of high coseismic slip, or extend outward of the ruptured faults. For the mainshock, rupture propagation stopped southward at the diffuse termination of the East Anatolian fault and tapered off northward into the Pütürge segment, some 20 km south of the 2020 Mw 6.8 Elaziğ earthquake, highlighting a potential seismic gap. These events underscore the high seismic potential of immature fault systems. 

Abstract The Sulaiman Fold Thrust (SFT) in Central Pakistan formed during the India‐Eurasia collision in the late Cenozoic. However, the mechanics of shortening of the brittle crust at time scales of seismic cycles is still poorly understood. Here, we use radar interferometry to analyze the deformation associated with the 2015 magnitude (Mw) 5.7 Dajal blind earthquake at the eastern boundary of the SFT. We use kinematic inversions to determine the distribution of slip on the frontal ramp and of flexural slip along active axial surfaces for the forward‐ and backward‐verging two end‐member models: a double fault‐bend‐fold system and a fault‐propagation‐fold. In both models, a décollement branches into a shallow ramp at approximately 7.5 km depth with coseismic folding in the hanging wall. The Dajal earthquake ruptured the base of the Boundary Thrust buried under the sediment from the Indus‐River floodplain, representing fault‐bend or fault‐propagation folding some 30 km off its nearest surface exposure. 

This paper provides an analysis of radio wave scattering for frequencies ranging from the microwave to the Terahertz band (e.g., 1 GHz - 1 THz), by studying the scattering power reradiated from various types of materials with different surface roughnesses. First, fundamentals of scattering and reflection are developed and explained for use in wireless mobile radio, and the effect of scattering on the reflection coefficient for rough surfaces is investigated. Received power is derived using two popular scattering models - the directive scattering (DS) model and the radar cross section (RCS) model through simulations over a wide range of frequencies, materials, and orientations for the two models, and measurements confirm the accuracy of the DS model at 140 GHz. This paper shows that scattering can become a prominent propagation mechanism as frequencies extend to millimeter-wave (mmWave) and beyond, but at other times can be treated like simple reflection. Knowledge of scattering effects is critical for appropriate and realistic channel models, which further support the development of massive multiple input-multiple output (MIMO) techniques, localization, ray tracing tool design, and imaging for future 5G and 6G wireless systems.