During the 1984 Marginal Ice Zone Greenland Sea Experiment, we carried out a field study on the relation between ice floe collisions and ocean swell. The experiment consisted of the deployment on separate ice floes of three buoys, each of which contained a compass and a set of triaxial accelerometers. The floes had characteristic diameters of 100 m and thicknesses of 1--5 m. From two major depolyments of these buoys, we gathered 16 days of data. From the vertical accelerometer data, we calculated the variation in the long-period ocean swell with time; from the horizontal accelerometers, we determined the individual and mean collision properties. Examination of the individual collisions showed that two types of collisions occurred: a short-period spike that recurred with the period of the ocean swell, and a longer period acceleration event that was uncorrelated with the swell. We observed several hundred of the first type of collision in our data set but only eight of the second type. The number of periodic collisions in a 9-min sample and the energy of these collisions were generally correlated with the ocean swell energy. The ocean swell measured at the floes had root-mean-square (rms) amplitudes of 1--30 mm and periods between 10 and 18 s. After removal of the ocean swell signal, the collisions had characteristic horizontal displacements of 5-35 mm, with rms velocities of the order of 1 mm s-1. ¿ American Geophysical Union 1987