Perth Canyon

{{Short description|Submarine canyon off the coast of Perth, Western Australia}} {{Use dmy dates|date=July 2019}} '''Perth Canyon''' is a submarine canyon located on the edge of the continental shelf off the coast of Perth, Western Australia, approximately {{convert|22|km|mi}} west of Rottnest Island. It was carved by the Swan River, likely before the Tertiary, when this part of the continental shelf was above sea level. It is an average of {{convert|1.5|km|ft|sigfig=1}} deep and {{convert|15|km|mi}} across, making it similar in dimension to the Grand Canyon.<ref name="Seddon 2004">{{cite book | last = Seddon | first = George | authorlink = George Seddon (academic) | title = Sense of Place | edition = Facsimile | year = 2004 | publisher = Bloomings Books | location = Melbourne | isbn = 1-876473-53-3}}</ref>

It occupies an area of {{convert|2900|km2|sqmi}} and ranges in depth from {{convert|700|to|4000|m|ft}}. Within a few kilometres its depth drops from {{convert|200|m|ft}} down to {{convert|1000|m|ft}}, and then it continues as a deep gully all the way out to the {{convert|4000|m|ft|adj=on}} depth, which is about another {{convert|30|km|mi|round=5}} further west. It contains the world's largest plunge pool{{mdash}}a depression in the canyon that is {{convert|2|km|mi}} long, {{convert|6|km|mi}} across, and {{convert|300|m|ft}} deep. The canyon is considered "a perfect spot" for deep sea fishing.

The Perth Canyon is a feeding ground for pygmy blue whales, especially at the rims of the abyss. It is also a training ground for the Royal Australian Navy Submarine Service, stationed at a naval base at nearby Garden Island.

In June 2006, the waters around the Perth Canyon were the site of an ocean vortex {{convert|200|km|mi}} in diameter and {{convert|1000|m|ft}} deep. It was visible from space, and scientists claimed at the time that it had the potential to affect the local climate and the climate further abroad. The vortex was described by scientists as a marine "death trap", as it sucked in fish larvae.<ref>{{cite news |title=Massive ocean vortex found off WA coast |url=http://www.theage.com.au/news/National/Massive-ocean-vortex-found-off-WA-coast/2006/06/02/1148956537754.html |newspaper=The Age |date=2 June 2006 |accessdate=14 July 2011}}</ref>

==See also== * Indian Ocean Gyre

==References== {{Reflist}}

Category:Landforms of Western Australia Category:Submarine canyons of the Indian Ocean