|Psychedelic wonder: Tourists have for decades been throwing coins into the Morning Glory Pool in Wyoming for luck. These have blocked its heat vents thereby reducing its temperature and causing a chemical reaction(dailymail.co.uk)|
And while the Morning Glory Pool in Wyoming with its stunning colours continues to attract visitors from around the world its appearance has undergone a dramatic change.
Just a few decades ago, the natural hot spring was a distinctive blue colour.
But now it has taken on a deep green hue with a distinct yellow and red ring around its circumference.
|1966: How the hot spring looked 45 years ago before the chemical reaction took place|
Tourists have for decades been throwing coins into the pool for luck. Unfortunately, these have blocked the pool's heat vents and reduced its temperature.
At the same time, chemicals from the coins have caused a reaction that has caused several bacteria to grow.
These have slowly worked its way to the water's edge, creating the predominantly yellow ring around the pure blue centre which has turned green as a result.
The algae is photosynthetic, thermophilic bacteria that can survive temperatures ranging from 64C to 107C.
Bacteria has slowly worked its way to the water's edge, creating the yellow ring around the pure blue centre which has turned green as a result
IT consultant Arun Yenumula, 30, took the top photograph of the Morning Glory Pool in Yellowstone National Park while on holiday with his wife.
He said: 'I had heard about the pool from friends and when I saw it I thought it was simply unbelievable.
'Each colour represents a different type of heat-seeking algae.
'An information board next to the pool called it "fading glory" because people threw rocks, stones, bottles and cans blocking the heat vents at the bottom, resulting in cooling the pool.
'The bacteria which thrive in real hot water started to die and the colours were fading. I felt really sad about the fact and how humans are destroying nature's beauty with their mindless acts.'
Mr Yenumula, from Seattle, Washington, added: 'Morning Glory is the most beautiful pool at Yellowstone National Park.
'It is unique and has a more diverse range of colours than anywhere else.'
Reaction: The algae is photosynthetic, thermophilic bacteria that can survive temperatures from 64C to 107C
Big draw: The pool attracts thousands of tourists from around the world every year