Thirty horizontal displacement time series from GPS sites in the area around the 2005 Kashmir earthquake show lateral spatial variations in displacement magnitude and relaxation time for the postseismic interval from 2005 to 2012. The observed spatial pattern of surface displacements can only be reproduced by finite element models of postseismic deformation in elastic over viscoelastic crust that include lateral differences in both the thickness of the elastic layer and the viscosity of the viscoelastic layer. Solutions reproducing the sign of horizontal displacements everywhere in the epicentral region also require afterslip on the portion of the fault dislocation in the viscoelastic layer but not in the elastic lid. Although there are substantial tradeoffs among contributions to postseismic displacements of the surface, the observations preclude both crustal homogeneity and shallow afterslip. In the best family of solutions, the thickness of the elastic upper crust differs by a factor of 5 and the viscosity of the middle and lower crust by an order of magnitude between domains north and south of a suture zone containing the Main Boundary Thrust and Main Mantle Thrust.

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.