Compelling Coastline Along Roebuck Bay

Compelling Coastline Along Roebuck Bay. This photograph taken from the International Space Station shows striking shoreline patterns at Roebuck Bay, on the coast of the desert landscape of Western Australia. The indents along the shoreline (center and left) are points where small, straight streams reach the bay. Even smaller tributaries give a feathered appearance to this shoreline. By contrast, the more typical meandering channel patterns of coastal wetlands appear on the top right.

Almost no human-built patterns are visible in the scene, even though the town of Broome lies just outside the image on the top right. The exceptions are the few fence lines crossing the straight streams in the bottom third of the image.

The regularity of the stream pattern seems to have its origin in the surrounding inland areas. Several inland dunefields show the same pattern of parallel “linear dunes.” Interestingly, the dunes are spaced roughly the same distance apart as the parcels of land between the straight streams at the coast. Both the dunes and the straight streams are aligned with the dominant winds out of the east. (Note that north is to the upper right.) It seems likely that dunes once occupied the bay shore and may have controlled the spacing and linearity on the straight streams. The phenomenon of streams forming in the parallel lows between linear dunes is well known in desert landscapes.

In all, this photograph shows about fifteen kilometers (10 miles) of coastline along Roebuck Bay. The bay also can be spotted in the lower left corner of this panoramic view taken from the Space Station on an earlier mission.

Credit: Astronaut photograph ISS044-E-885 was acquired on June 11, 2015, with a Nikon D4 digital camera using an 1150 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 44 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Programsupports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Texas State U., Jacobs Contract at NASA-JSC.