Q: Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.
Paragraph- Sent 1: You may be wondering, how can a glacier get so big?
Sent 2: Why does it move?
Sent 3: These are both good questions.
Sent 4: In the winter months, precipitation falls as snow.
Sent 5: This solid form of water builds up on the ground as long as the temperatures stay cold enough.
Sent 6: As the temperature rises, the snow starts to melt.
Sent 7: The frozen water changes state back into a liquid state.
Sent 8: Nearer the poles, summer does not last very long.
Sent 9: If the summer is long enough and warm enough, all the snow may melt.
Sent 10: This is what typically happens now.
Sent 11: The earth was a little cooler 12,000 years ago.
Sent 12: As a result, during the summer months, that amount of snow did not melt.
Sent 13: It may have only been an inch or so of snow that melted.
Sent 14: The following winter, snow fell on top of this left-over snow.
Sent 15: This next winters snowfall had a head start.
Sent 16: Year after year, the snow that did not melt became thicker and thicker.
Sent 17: Inch by inch the snow started to build up.
Sent 18: Over many years, layer upon layer of snow compacted and turned to ice. 
Question: How does the snow turn into ice?.
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
By get accumulated and compacted.