The
third largest hot spring in the world, the Grand Prismatic I think
is the most amazing natural wonder on the Planet.
The vivid
colours in the spring are the result of pigmented bacteria in
the microbial mats that grow around the edges of the mineral-rich
water. The bacteria produce colors ranging from green to red;
the amount of color in the microbial mats depends on the ratio
of chlorophyll to carotenoids and on the temperature of the water
that favors one bacterium over another. In the summer, the mats
tend to be orange and red, whereas in the winter the mats are
usually dark green. The center of the pool is sterile due to extreme
heat.
The deep blue
colour of the water in the center of the pool results from the
intrinsic blue colour of water, itself the result of water's selective
absorption of red wavelengths of visible light. Though this effect
is responsible for making all large bodies of water blue, it is
particularly intense in Grand Prismatic Spring because of the
high purity and depth of the water in the middle of the spring