Why are the Blue Mountains in NSW Australia blue?

Hi,
Thanks for the question.

They are not actually blue, but named "Blue Mountains" due to the
distinct bluish haze - originating from vapor released by the abundant
eucalyptus trees growing on the mountains. This effect from a distance
makes the mountains seem blue.

"The Blue Mountains are known for their contrasts between plateau,
cliff and valley landscapes, and the famous blue haze, a vapor
produced by numerous eucalypt trees."
http://www.vnc.qld.edu.au/enviro/bluemtns/blue.htm


"In 1788 the Blue Mountains were originally named "Carmarthen Hills"
and "Landsdowne Hills" by Governor Phillip, however, it wasn?t long
after, that the distinctive blue haze surrounding the area saw the
change in name to the Blue Mountains.
The Blue Mountains is densely populated by oil bearing Eucalyptus
trees. The atmosphere is filled with finely dispersed droplets of oil,
which, in combination with dust particles and water vapor, scatter
short-wave length rays of light which are predominantly blue in
colour. "
http://www.bluemts.com.au/tourist/about/history-detail.asp



Please see here many more interesting details regarding the Blue
Mountain's geography, geology, history, vegetation, fauna and flora:
http://www.bluemts.com.au/ecotourism/nature/default.htm

Some general facts about The Blue Mountains of New South Wales, Australia:
"The Blue Mountains of New South Wales, Australia, roughly 100
kilometres west of Sydney, are a range of sandstone mountains that
reach to 1111 metres above sea level at their highest, One Tree Hill,
and form part of the Great Dividing Range that runs roughly parallel
to the east and southeast coast of Australia for thousands of
kilometres. Blue Mountains also refers to the City of the Blue
Mountains (or Blue Mountains City Council), a local government area
within the range; or specifically to the Blue Mountains National Park.
The Blue Mountains take the form of a plateau with deep, rugged gorges
of up to 1000 metres. The Blue Mountains cover an area of 1436 square
kilometres (554 square miles).
The Blue Mountains is part of the Greater Blue Mountains Area, listed
as a World Heritage Site by UNESCO."
http://en.wikipedia.org/wiki/Blue_Mountains


Regards
Landog-ga




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We have been debating this question with overseas visitors and felt
the reason was not fully verified - we bow to your authority (???)

And, to all that, for European eyes the eucalyptus trees' leaves have
a bluish cast that reinforces the impression.

Hi!

The Blue Mountains are an hour away from me, and Landog's explanation
is certainly the local received wisdom, though I don't know that it's
been scientifically tested. The colour can be quite marked.