Question

英语有个句子读不懂，请高手指教

A surplus allows snow to accumulate and for the pressure of snow accumulated over the years to transform buried snow into glacial ice with a depth great enough for the ice to flow.
我主要是 结构读不懂，所以 句子无法理解
请高手 分析下 该句子的结构

该句子出自下文
Glaciers are open systems, with snow as the system's input and meltwater as the system’s main output. The glacial system is governed by two basic climatic variables: precipitation and temperature. For a glacier to grow or maintain its mass, there must be sufficient snowfall to match or exceed the annual loss through melting, evaporation, and calving, which occurs when the glacier loses solid chunks as icebergs to the sea or to large lakes. If summer temperatures are high for too long, then all the snowfall from the previous winter will melt. Surplus snowfall is essential for a glacier to develop. A surplus allows snow to accumulate and for the pressure of snow accumulated over the years to transform buried snow into glacial ice with a depth great enough for the ice to flow. Glaciers are sometimes classified by temperature as faster-flowing temperate glaciers or as slower-flowing polar glaciers.

Answer 1

A surplus allows snow 【to accumulate】and （for the pressure of snow accumulated over the years） 【to transform buried snow into glacial ice】 （with a depth great enough for the ice to flow）.
最简化：A surplus allows snow to accumulate and totransform.
这句话的谓语动词是allow。连接两个动词不定式to do，表示并列的关系。
翻译：剩余的让雪能够累积起来，并在长年累积的雪的压力下，从雪转变为深得足够它流动的冰川冰。
PS,自己翻得，可能没什么美感，不过意思差不多拉。