Graded English news article at B1 level.
An international team of climate scientists has completed the deepest ice core ever drilled in Antarctica, reaching a depth of 4,200 meters below the surface. The core, extracted from a site near Dome C, contains trapped air bubbles that provide a direct record of Earth's atmosphere stretching back 1.5 million years. Analysis of the ice has revealed that ancient climate cycles shifted in length from 41,000-year cycles to 100,000-year cycles approximately 900,000 years ago, a phenomenon scientists have long struggled to explain. The new data suggests that a gradual decline in atmospheric carbon dioxide levels was the primary driver of this shift. The findings have significant implications for understanding current climate change, as they demonstrate how relatively small changes in greenhouse gas concentrations can trigger major shifts in global climate patterns.
This piece is graded at CEFR level B1, it belongs to science, published on 2026-07-17.
تیمی بین‌المللی از دانشمندان آب‌وهوا عمیق‌ترین هسته یخی را که تاکنون در قطب جنوب حفاری شده تکمیل کرده‌اند و به عمق ۴,۲۰۰ متر زیر سطح رسیده‌اند. این هسته که از سایتی نزدیک گنبد C استخراج شده، حباب‌های هوای به دام افتاده‌ای را در خود جای داده که مستقیماً سابقه‌ای از جو زمین را برای ۱.۵ میلیون سال گذشته ارائه می‌دهد.
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