There is much about earthquakes that is a mystery, even to scientists. But a new video—showing four earthquakes in both real time and slow motion—is showing us how the ground moves as a quake ripples through it.

The video is the result of a study done by geologists working for Signal Hill Petroleum and Nodal Seismic. In 2011, the scientists deployed seismic arrays consisting of 5300 nodes spaced 330 feet apart to measure the 3D rock formation below their Long Beach oilfield. "The sensors used by the seismologists are so sensitive that they even pick up human activity, including traffic," writes George Dvorksy at io9. "This video ... clearly shows the earthquake propagating from the epicenter and across the city in a coherent succession of seismic waves. Though earthquakes might feel completely chaotic, this visualization clearly shows that they're anything but."