Many earthquakes strike with a jolt—but some faults creep quietly beneath our feet. New CIRES research uncovers these silent shifts through the most comprehensive record yet of shallow aseismic slip events—tiny fault movements that don’t cause shaking, but reveal how Earth’s crust releases stress.

In a newly published dataset, CIRES scientists cataloged four decades of fault motion using instruments across California, Utah, Türkiye, Pakistan, and Israel. The data helped them identify three kinds of slip: episodic creep events, months-long creep surges, and the newly discovered creeplet, a minuscule motion less than a tenth of a millimeter. Each data point logs the date and location of the slip, the instrument and network that detected it, the distance the fault moved, the duration of the event, and whether it may have been triggered by a nearby earthquake (within a 500 km radius).

Understanding these quiet motions helps scientists improve earthquake models and assess potential triggers, bringing us one step closer to decoding the planet’s subtle warning signs. 

View the dataset on Zenodo.