All these types of strainmeters can measure deformation over frequencies from a few Hz to periods of days, months, and years. This allows them to measure signals at lower frequencies than can be detected with seismometers. Most strainmeter records show signals from the earth tides, and seismic waves from earthquakes. At longer periods, they can also record the gradual accumulation of stress (physics) caused by plate tectonics, the release of this stress in earthquakes, and rapid changes of stress following earthquakes.