Sediments tell a tsunami story Trying to understand where major earthquakes and tsunamis might occur requires analysis of the sediments pouring into a subduction zone. Thick sediments were expected to limit earthquake and tsunami size in the Sumatran megathrust event in 2004, but the magnitude 9.2 earthquake defied expectations. Hüpers et al. analyzed sediments recovered from the Sumatran megat...

The supposed low viscosity of serpentine may strongly influence subduction-zone dynamics at all time scales, but until now its role could not be quantified because measurements relevant to intermediate-depth settings were lacking. Deformation experiments on the serpentine antigorite at high pressures and temperatures (1 to 4 gigapascals, 200 degrees to 500 degrees C) showed that the viscosity o...

Successful scientific theories provide theoretical understanding for reliable deterministic or probabilistic forecasting of events. In the past decades the volume of data obtained within the fields of structural geology and tectonics has increased enormously, but the theoretical understanding of the processes that generate these data has not advanced at the same rate. For example, after decades...

The 3D finite difference modeling of the wave propagation of M>8 earthquakes in subduction zones in a realistic-size earth is very computationally intensive task. We use a parallel finite difference code that uses second order operators in time and fourth order differences in space on a staggered grid. We develop an efficient parallel program using message passing interface (MPI) and a kinemati...

Double Benioff zones provide opportunities for insight into seismogenesis because the underlying mechanism must explain two layers of deep earthquakes and the separation between them. We characterize layer separation inside subducting plates with a coordinate rotation to calculate the slab-normal distribution of earthquakes. Benchmark tests on well-established examples confirm that layer separa...