The Department of Conservation (DoC) was made aware the pair had not returned to Plateau Hut on Monday morning.
The search and rescue effort spanned three days, when weather allowed.
“Once a weather window appeared, the DoC Search and Rescue team, supported by The Helicopter Line [THL] and New Zealand Police, were able to conduct a search of the mountain,” said Aoraki area commander Inspector Vicki Walker.
“The first opportunity for an aerial search occurred late Tuesday evening, however, they were not located. However, because they noted their intentions, it drastically narrowed the area we had to search.”
The search was ramped up on Wednesday using a Recco Sar detector suspended under a THL helicopter.
“With the aid of the detector and search and rescue staff, we were able to identify a key area of interest and located some items of climbing equipment,” Walker said.
“A visual investigation of this area has led to the determination that the overdue climbers have been caught in a significant ice avalanche within a known icefall hazard zone on the upper Linda Glacier,” Walker said.
“Because of the scale and volume of material involved, we don’t believe this avalanche was survivable.”
DoC Aoraki/Mt Cook operations manager Sally Jones said the area remains too unstable for ground crews to access, or for a recovery operation to be attempted.
“This is a tragic outcome, and our thoughts are with the climbers’ family and friends.
“The Linda Glacier is an unforgiving alpine environment. Conditions can change rapidly and even highly experienced climbers are exposed to unexpected hazards including icefall, crevasses, avalanches and extreme weather,” she said.
“Aoraki is a place of immense beauty and significance, but it also can be extremely brutal in terms of what it can throw at those who attempt to climb it.”
While aerial reconnaissance had not been able to pinpoint where the bodies of the climbers might be, Walker said police would consider a recovery operation if warmer weather allowed.
“Sadly, for now, we can’t reach them, and they lie in rest on the maunga and our sympathy is with their whānau,” Walker said.
The two climbers are the fifth and sixth mountaineers to die on New Zealand mountains in the past four weeks.
Two climbers perished on Aoraki/Mt Cook in late November, while two more died on Sabre Peak last weekend.
