Selkirk Island is not the only place where Landsat has seen vortex streets. Other places where this phenomenon is common are nearby Robinson Crusoe Island; the Kuril Islands, Russia; Guadalupe Island, off the western coast of Mexico; and the Aleutian Islands, Alaska. The reason for the cloud patterns is the same: tall, steep-sided islands that affect the motion of passing clouds. That first image over Selkirk Island in September 1999, however, is still the clearest vortex street Landsat has recorded.