Formation of cycloidal features on Europa

Cycloidal patterns are widely distributed on the surface of Jupiter's moon Europa. Tensile cracks may have developed such a pattern in response to diu rnal variations in tidal stress in Europa's outer ice shell. When the tensi le strength of the ice is reached, a crack may occur. Propagating cracks wo uld move across an ever-changing stress field, following a curving path to a place and time where the tensile stress was insufficient to continue the propagation. A few hours Later, when the stress at the end of the crack aga in exceeded the strength, propagation would continue in a new direction. Th us, one arcuate segment of the cycloidal chain would be produced during eac h day on Europa. For this model to work, the tensile strength of Europa's i ce crust must be Less than 40 kilo-pascals, and there must be a thick fluid Layer below the ice to allow sufficient tidal amplitude.