Experimental observations in JET indicate that type I ELMs are associated with rapid movements of strike points. In strike positions are identified with 2 different diagnostics: as the position with maximum ion saturation current, measured with divertor target Langmuir probes, and as the position of highest temperature and/or heat flux measured with an infrared camera. The apparent strikes often shift as much as 20cm in 100ms or less (limit of temporal resolution), but in the next data point the strikes settle nearer their original position, displaced toward the plasma centre by 2-5cm from the pre-ELM position.