Floods of record

摘要

One of the quirks of the Earth's stratigraphic recording system is that it operates in fits and starts, archiving surface conditions for a while and then suddenly switching off. The sedimentary 'record' button is evidently pretty finicky. It is sensitive to external controls, but also to the internal dynamics of the sediment-deposition system. An intriguing example of how the recording process works is given on page 493 of this issue. Aalto et al. show how changes in the way that rainwater is delivered to a river system, driven by the El Nino/Southern Oscillation (ENSO) climate cycle in the Pacific Ocean, can switch one of the major processes of sedimentation on and off.