What is Blue Lake (South Australia)?
{{Infobox lake |lake_name = Blue Lake |image_lake =Blue Lake, Mount Gambier.jpg |caption_lake = Blue Lake |image_bathymetry = |caption_bathymetry = |location = [[Mount Gambier, South Australia]] |coords = {{coord|37|50|48|S|140|46|41|E|region:AU-SA_type:waterbody|display=inline,title}} |type = [[Crater lake]] |inflow = |outflow = |catchment = Blue Lake Catchment Area |basin_countries = Australia |length = {{convert|1087|m|ft|abbr=on}} |width = {{convert|657|m|ft|abbr=on}} |area = {{convert|70|ha|abbr=on}} |depth = {{convert|72|m|ft|abbr=on}} |max-depth = 77 m |volume = |residence_time = |shore = None |elevation = |islands = None |cities = None }} [[File:Adam Lindsay Gordon monument, South Australia.jpg|thumb|150px|The Adam Lindsay Gordon obelisk at the Blue Lake.]] The '''Blue Lake''' is in [[Mount Gambier, South Australia]]. It may be a [[dormant volcano|dormant volcanic]] crater. It is one of four crater lakes on Mount Gambier. Over the past 30 to 40 years the [[water table]] has dropped. The Blue Lake changes colour, from grey to bright blue. Different dates have been given for its last eruption, of 28,000&nbsp;years ago,<ref>{{cite web |url=https://dl.dropboxusercontent.com/u/85291726/Grimes.Volc.Ages.pdf |title=The ages of our volcanoes |access-date=2013-08-22 |first=Ken |last=Grimes |year=2013 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304101342/https://dl.dropboxusercontent.com/u/85291726/Grimes.Volc.Ages.pdf |url-status=deviated |archivedate=2016-03-04 |archiveurl=https://web.archive.org/web/20160304101342/https://dl.dropboxusercontent.com/u/85291726/Grimes.Volc.Ages.pdf }}</ref> 4342&nbsp;years ago,<ref>{{cite web |url=http://www.seismicity.segs.uwa.edu.au/welcome/seismicity_in_australia/volcanoes_and_earthquakes_in_southeastern_australia |title=Volcanoes & Earthquakes in SE Australia |access-date=2008-05-07 |publisher=[[University of Western Australia]] |archive-date=2008-05-10 |archive-url=https://web.archive.org/web/20080510110405/http://www