洞穴的形成需要火山气体和热量的稳定释放，海拔高到足以防止每年的大量降雪在夏季融化。
The cave-making recipe calls for a steady emission of volcanic gas and heat, a heavy annual snowfall at an elevation high enough to keep it from melting during the summer.
加拿大北极群岛一般少有新的冰川形成，并且每年的降雪量差不多。 但冰雪融化量却大不相同，所以冰量的变化主要由夏季融化量决定。
Sharply increased mass loss from glaciers and ice caps in the Canadian Arctic Archipelago.
夏季过高的温度和冬季降雪量减少的综合因素导致了雪线的后退。
A combination of higher summer temperatures and lower winter snowfall is causing the retreat.
所以，本次突变系夏季温度升高、消融剧增为主导，叠加年降雪量递减的综合结果。
Thus, this abrupt change was mainly caused by a temperature increase in summer as well as an annual snowfall decrease.
所以，本次突变系夏季温度升高、消融剧增为主导，叠加年降雪量递减的综合结果。
Thus, this abrupt change was mainly caused by a temperature increase in summer as well as an annual snowfall decrease.
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