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The Russian-Ukrainian conflict spawned a high-intensity war that shattered decades of peace in Europe. The use of drones and social media elevates open-source intelligence as a critical strategic asset. However, information from these sources is sporadic, difficult to confirm, and prone to manipulation. Here, we use open-access spaceborne remote sensing data to probe the damage to infrastructure on and off the frontline at the city, region, and country-wide scales in Ukraine. Nighttime light data and Synthetic Aperture Radar images reveal widespread blackout and unveil the destruction of battleground cities, offering contrasted perspectives on the impact of the conflict. Optical satellite images capture extensive flooding along the Dnipro River in the aftermath of the breach of the Kakhovka dam. Leveraging visible, near-infrared, and microwave satellite data, we bring to light disruption of human activities, havoc in the environment, and the annihilation of entire cities during the protracted conflict. Open-source remote sensing can offer objective information about the nature and extent of devastation during military conflicts. 

The collision between the Indian and Eurasian plates drives tectonic uplift and evolving landscapes over geological time scales. Much of this evolution is accommodated by seismic processes. However, the relationship between long-term geological processes and short-term seismic cycles is challenging to unravel because of their disparate spatial and temporal scales. Here, we investigate the impact of the internal dynamics of the orogenic wedge on the cycle of Himalayan earthquakes, linking structural models with seismic cycle simulations to show how earthquake patterns may have changed over time. Balanced cross-sections with fault-bend folding at different stages of structural evolution show that frontal thrusts in the Himalayas accumulate slip at different rates across the wedge and over time, depending on the architectural layout of the thrust sheet. Along-strike variations in structural evolution along the Himalayan front may lead to lateral and down-dip segmentation of long-term slip rate, affecting the magnitude and recurrence patterns of earthquakes. Spatio-temporal earthquake patterns may shift every ∼0.3-1.3 Myr as the hanging wall evolves, with implications for seismic hazards in the Nepal Himalayas. 

Abstract The collision between India and Eurasia mobilizes multiple processes of continental tectonics. However, how deformation develops within the lithosphere across the Tibetan Plateau is still poorly known and a synoptic view is missing. Here, we exploit an extensive geodetic observatory to resolve the kinematics of this diffuse plate boundary and the arrangement of various mechanisms down to upper-mantle depths. The three-dimensional velocity field is compatible with continental underthrusting below the central Himalayas and with delamination rollback below the western syntaxis. The rise of the Tibetan Plateau occurs by shortening in the Indian and Asian crusts at its southern and northwestern margins. The subsidence of Central Tibet is associated with lateral extrusion and attendant lithospheric thinning aided by the downwelling current from the opposite-facing Indian and Asian collisions. The current kinematics of the Indian-Eurasian collision may reflect the differential evolution of the inner and outer Tibetan Plateau during the late Cenozoic. 

Abstract The empirical rate‐ and state‐dependent friction law is widely used to explain the frictional resistance of rocks. However, the constitutive parameters vary with temperature and sliding velocity, preventing extrapolation of laboratory results to natural conditions. Here, we explain the frictional properties of natural gouge from the San Andreas Fault, Alpine Fault, and the Nankai Trough from room temperature to ∼300°C for a wide range of slip‐rates with constant constitutive parameters by invoking the competition between two healing mechanisms with different thermodynamic properties. A transition from velocity‐strengthening to velocity‐weakening at steady‐state can be attained either by decreasing the slip‐rate or by increasing temperature. Our study provides a framework to understand the physics underlying the slip‐rate and state dependence of friction and the dependence of frictional properties on ambient physical conditions. 

Abstract The frictional properties of faults control the initiation and propagation of earthquakes and the associated hazards. Although the ambient temperature and instantaneous slip velocity controls on friction in isobaric conditions are increasingly well understood, the role of normal stress on steady‐state and transient frictional behaviors remains elusive. The friction coefficient of rocks exhibits a strong dependence on normal stress at typical crustal depths. Furthermore, rapid changes in normal stress cause a direct effect on friction followed by an evolutionary response. Here, we derive a constitutive friction law that consistently explains the yield strength of rocks from atmospheric pressure to gigapascals while capturing the transient behavior following perturbations in normal stress. The model explains the frictional strength of a variety of sedimentary, metamorphic, and igneous rocks and the slip‐dependent response upon normal stress steps of Westerly granite bare contact and synthetic gouges made of quartz and a mixture of quartz and smectite. The nonlinear normal stress dependence of the frictional resistance may originate from the distribution of asperities that control the real area of contact. The direct and transient effects may be important for induced seismicity by hydraulic fracturing or for naturally occurring normal stress perturbations within fault zones in the brittle crust. 

Long paleoseismic records on mature faults suggest potentially chaotic recurrence patterns with cycles of strain accumulation and release that challenge simple slip-or time-predictable recurrence models. In apparent contradiction, the relatively small variability of earthquake recurrence times on these faults is often characterized as quasi-periodic, implying much regularity in the underlying mechanics. To reconcile these observations, we simulate one of the longest paleoearthquake records – the 24-event record from the Hokuri Creek site on the Alpine fault in New Zealand – using a physical model of rate-and state-dependent friction. In a parameter space formed by three non-dimensional parameters, a sea of parameters produces periodic earthquake recurrence behavior. Only a few models are characterized by fundamentally aperiodic recurrence patterns, in parametric islands of chaos. Complex models that produce partial and full ruptures of the Alpine fault can explain the earthquake recurrence behavior of the Alpine fault, reproducing up to 11 consecutive events of the Hokuri Creek paleoseismic record within uncertainties. The breakdown of the slip-and time-predictable recurrence patterns occurs for faults that are much longer than the characteristic nucleation size. The quasi-periodicity of seismic cycles is compatible with the nonlinear and potentially chaotic underlying mechanical system, posing an inherent challenge to long-term earthquake prediction. 

Abstract Establishing a constitutive law for fault friction is a crucial objective of earthquake science. However, the complex frictional behavior of natural and synthetic gouges in laboratory experiments eludes explanations. Here, we present a constitutive framework that elucidates the rate, state, and temperature dependence of fault friction under the relevant sliding velocities and temperatures of the brittle lithosphere during seismic cycles. The competition between healing mechanisms, such as viscoelastic collapse, pressure‐solution creep, and crack sealing, explains the low‐temperature stability transition from steady‐state velocity‐strengthening to velocity‐weakening as a function of slip‐rate and temperature. In addition, capturing the transition from cataclastic flow to semi‐brittle creep accounts for the stabilization of fault slip at elevated temperatures. We calibrate the model using extensive laboratory data on synthetic albite and granite gouge, and on natural samples from the Alpine Fault and the Mugi Mélange in the Shimanto accretionary complex in Japan. The constitutive model consistently explains the evolving frictional response of fault gouge from room temperature to 600°C for sliding velocities ranging from nanometers to millimeters per second. The frictional response of faults can be uniquely determined by the in situ lithology and the prevailing hydrothermal conditions.