Seasonal slow slip in landslides as a window into the frictional rheology of creeping shear zones.

Whether Earth materials exhibit frictional creep or catastrophic failure is a crucial but unresolved problem in predicting landslide and earthquake hazards. Here, we show that field-scale observations of sliding velocity and pore water pressure at two creeping landslides are explained by velocity-strengthening friction, in close agreement with laboratory measurements on similar materials. This suggests that the rate-strengthening friction commonly measured in clay-rich materials may govern episodic slow slip in landslides, in addition to tectonic faults.

The life span of fault-crossing channels.

Successive earthquakes can drive landscape evolution. However, the mechanism and pace with which landscapes respond remain poorly understood. Offset channels in the Carrizo Plain, California, capture the fluvial response to lateral slip on the San Andreas Fault on millennial time scales.

Sediment supply controls equilibrium channel geometry in gravel rivers.

In many gravel-bedded rivers, floods that fill the channel banks create just enough shear stress to move the median-sized gravel particles on the bed surface (). Because this observation is common and is supported by theory, the coincidence of bankfull flow and the incipient motion of has become a commonly used assumption. However, not all natural gravel channels actually conform to this simple relationship; some channels maintain bankfull stresses far in excess of the critical stress required to initiate sediment transport.

Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body.

The Altiplano-Puna Magma Body (APMB) in the Central Andes is the largest imaged magma reservoir on Earth, and is located within the second highest orogenic plateau on Earth, the Altiplano-Puna. Although the APMB is a first-order geologic feature similar to the Sierra Nevada batholith, its role in the surface uplift history of the Central Andes remains uncertain. Here we show that a long-wavelength topographic dome overlies the seismically measured extent of the APMB, and gravity data suggest that the uplift is isostatically compensated.

A signature of transience in bedrock river incision rates over timescales of 10(4)-10(7) years.

Measured rates of river incision into bedrock are commonly interpreted as proxies for rates of rock uplift (see refs 1 and 2, for example) and indices of the strength of climatic forcing of erosion over time (see refs 3 and 4, for example). This approach implicitly assumes that river incision rates are in equilibrium with external forcings over a wide range of timescales. Here we directly test this assumption by examining the temporal scaling of bedrock river incision from 155 independent measurements of river incision compiled from 14 sites.