At the peak of activity earlier this year, the researchers lowered the drill an extra hundred feet deeper into the ice every day and another 365 years deeper into the past.
在今年早些时候的探索高峰期时， 研究者们把钻头再往冰层中 多钻探了一百多英尺， 从而了解了 比之前更早的365年的历史。