When a magnitude 6.8 earthquake shook Olympia, Wash., in 2001, shop owner Jason Ward discovered that a sand-tracing pendulum had recorded the vibrations in the image above.

Seismologists say that the “flower” at the center reflects the higher-frequency waves that arrived first; the outer, larger-amplitude oscillations record the lower-frequency waves that arrived later.

“You never think about an earthquake as being artistic — it’s violent and destructive,” Norman MacLeod, president of Gaelic Wolf Consulting in Port Townsend, told ABC News. “But in the middle of all that chaos, this fine, delicate artwork was created.”