Later in the clip Ryan points the camera at the thousands of tonnes of rock and ice flowing down the steep decline like a raging river.
As he is filming, Ryan can be heard saying: "I don't know if I want to go down there anymore. It is huge, it is just flying. It is like a liquid.
"The snow line is now lowering so I guess we can ski further down." He adds: "It is still flowing down there, crazy. The mountainside is going to collapse."
Ryan captured the footage of the incredible glacier collapse, known as a serac fall, from the Whymper Saddle pass in the park on November 9.
The amateur photographer from Christchurch said: "After weaving through crevasses and ice fall we were glad to relax on the high ground of Whymper Saddle.
"Our map suggested good skiing terrain below us. Looking down into the valley it was obvious our intended ski line was threatened by a few dangers.
"The large mass of loose rock and ice was a big concern, along with the rapidly warming temperatures increasing the risk of avalanches.
"While we were talking the amount of rock fall began to steadily increase.
"It looked as if something was going to happen so I started filming. The collapse was quite loud sounding similar to the ocean crashing on a rocky coastline.
"Rock and ice mixed into a massive slurry that gouged its way down the mountain at impressive speed.
"The avalanche slowed down, spread out, adding its mass to the glacier below. It was cool to see up close and was a spectacular natural process.
"Our map suggested good skiing terrain below us. Looking down into the valley it was obvious our intended ski line was threatened by a few dangers.
"The large mass of loose rock and ice was a big concern, along with the rapidly warming temperatures increasing the risk of avalanches.
"While we were talking the amount of rock fall began to steadily increase.
'It looked as if something was going to happen so I started filming. The collapse was quite loud, sounding similar to the ocean crashing on a rocky coastline.
"Rock and ice mixed into a massive slurry that gouged its way down the mountain at impressive speed.
"The avalanche slowed down and spread out, adding its mass to the glacier below. It was cool to see up close and was a spectacular natural process."
- Daily Mail