Abstract - Displacements on tectonic faults primarily accrue during earthquakes at rates that vary through time. To
examine the processes that underlie the temporal changes in fault displacement rates we analyse
displacements and displacement rates for time periods from the present to 5, 10, 20, 300, 500, 1000 and
5000 kyr for 261 active reverse or normal faults from a worldwide dataset. Displacement rates depart from
million-year average rates by up to three orders of magnitude with the size of these departures inversely
related to the duration of the sample period and to fault length. Short-term (< 20 kyr) displacement rates
generally span a greater range on small faults than large, a feature which suggests more variable growth on
smaller faults. Simple earthquake-slip modeling shows that variations in displacement rates require changes
in both recurrence interval and slip per event and do not support the Characteristic-slip earthquake model.
As long as fault system strain rates are uniform, displacement rates generally become constant over time
periods between 20 and 300 kyr, with the length of time required to reach stability being inversely related to
the regional basin-wide strain rates. Stable long-term displacement rates and fluctuations in earthquake
recurrence intervals and slip arise, in part, due to fault interactions.
Earth and Planetary Science Letters, 278, 186-197, 2009.