The Exmouth Gulf, western Australia, is bounded on the west by the Cape Ranges; near the base of the peninsula the Learmonth Airfield, site of a solar observatory, can be seen. Spit-accretion ridges formed on ancient beaches extend along the western edge of the peninsula, which today is lined by the Ningaloo Reef. Red mud carried by floodwaters, the result of Hurricane Bobby the previous week, cover flat coastal land along the eastern side of the gulf. The mud is mixing slowly with marine water as it filters through passes between mangrove-covered islands. A filamentous pattern in the gulf probably indicates a plankton bloom. Island paleodunes stretching from south to north cover the landscape.