Aparticle moves in an elliptical or circular motion. it is most likely a particle in which type of wave

Surface waves from an earthquake shake the ground back and forth and up and down. So basically in a circular motion. This wave is the most dangerous wave released during and earthquake and it comes after the p and s waves. The Surface wave is the last wave that comes after the other 2. So yea' these surface waves move in a circular motion.

The center is basically the heart of it