New Zealand's highest and most deadly peak, Mount Cook, a magnet for mountaineers from around the world, is shrinking according to surveyors who have lowered it by 30 metres (98 feet). Mount Cook, which has claimed more than 200 lives, is currently listed at 3,754 metres, but a new study puts it at 3,724 metres. National School of Surveying researcher Pascal Sirguey said the shrinkage was the result of a reshaping of the mountain's ice cap following a rock-ice collapse in 1991. "As a result the ice cap has been subject to erosion over the past 20 years," Sirguey said when releasing his findings on Thursday. "While the effects of climate change may spring to mind as an explanation, it is probably a case of a simple change in the geomorphology of the mountain." Because of the technical difficulty in climbing Mount Cook, which is also known by its indigenous name Aoraki, it has become a favourite challenge for mountaineers from around the world.