<P> When the lake is full, it has the same salinity level as the sea, but as the lake dries up and the water evaporates, salinity increases . </P> <P> The lake was named in honour of Edward John Eyre, who was the first European to see it, in 1840 . The lake's official name was changed in December 2012 to combine the name "Lake Eyre" with the indigenous name, Kati Thanda . The native title over the lake and surrounding region is held by the Arabana people . </P> <P> Kati Thanda--Lake Eyre is located in the deserts of central Australia, in northern South Australia . The Lake Eyre Basin is a large endorheic system surrounding the lakebed, the lowest part of which is filled with the characteristic salt pan caused by the seasonal expansion and subsequent evaporation of the trapped waters . Even in the dry season there is usually some water remaining in Kati Thanda--Lake Eyre, normally collecting in over 200 smaller sub-lakes within its margins . The lake was formed by aeolian processes after tectonic upwarping occurred to the south subsequent to the end of the Pleistocene epoch . </P> <P> During the rainy season the rivers from the north - east part of the Lake Eyre Basin (in outback (south - west and central) Queensland) flow towards the lake through the Channel Country . The amount of water from the monsoon determines whether water will reach the lake and if it does, how deep the lake will get . The average rainfall in the area of the lake is 100 to 150 millimetres (3.9 to 5.9 in) per year . </P>

Where does the salt in lake eyre come from