Editing Houtman Abrolhos (section)

===Bathymetry===
The Houtman Abrolhos lies in the Indian Ocean about 60 kilometres (40&nbsp;mi) off the coast of Western Australia, near the edge of Australia's [[continental shelf]]. At less than 50 metres (160&nbsp;ft) deep, the shelf is quite shallow. It is also fairly level, the depth increasing to the west at a modest gradient of about 1.3 metres per kilometre (7&nbsp;ft/mi). About five kilometres (3&nbsp;mi) to the west of the Houtman Abrolhos lies the [[shelf break]], beyond which the seabed falls away much more steeply, averaging around 50 metres per kilometre (260&nbsp;ft/mi).<ref name = "Pearce 1997">{{cite book | first = AF | last = Pearce | year = 1997 | chapter = The Leeuwin Current and the Houtman Abrolhos Islands, Western Australia | editor = Wells, FE | title = The Marine Flora and Fauna of the Houtman Abrolhos Islands, Western Australia | volume = 1 | pages = 11–46 | publisher = Western Australian Museum | location = Perth}}</ref>

The islands of each island group arise from a single [[carbonate platform]], so the waters within an island group are mostly shallow. The channels between groups are {{convert|40|to|50|m}} deep, so no impediment to the exchange of offshore and inshore waters.<ref name="Pearce 1997"/>