It was exactly 100 years ago that Alfred Wegener discovered continental drift. Since then, the motion of the plates has been mainly treated as constant at year and decade time scales. However, with the advent of space-geodetic measurements and the recent improvements in the resolution of position estimates at continuously monitoring GNSS stations it is now possible to observe time-dependent, transient motions, related to more subtle physical processes than those envisioned by Wegener.
For example, one of the remarkable discoveries of the past decades is the existence of periodic slow-slip at many convergent plate boundaries. In 2001, transient slow slip was detected at the northern Cascadia Subduction Zone as a result of careful analysis of accurate, continuous GPS time-series [Dragert et al., 2001]. In Cascadia the slow slip repeats itself with a surprising regularity of 14 to 15 months [Miller et al., 2002] and usually is accompanied by a seismic tremor. Since then, other studies have reported slow slip events and tremor at many other subduction zones around the world.
The wide-spread occurrence of these transient, time-dependent events suggests fundamentally different physical processes take place at the fault interface, with important implications for the dynamics and earthquake potential.
We welcome contributions that address theoretical and observational time-dependent motions on time scales of days to months to years at convergent margins and their implications for subduction dynamics and other convergent plate boundaries around the world.