Ice Core Analysis
The retrieval and paleoclimatological analysis of cylindrical ice samples extracted from deep polar ice sheets and alpine glaciers.
Governing formula
Paleotemperature Proxy δ¹⁸O = ((¹⁸O/¹⁶O)_sample / (¹⁸O/¹⁶O)_standard - 1) × 1000‰
SI unit
Parts per thousand (‰ δ¹⁸O) / ppm (CO₂)
In depth
Ice cores contain trapped air bubbles that preserve direct historical samples of ancient atmosphere gas composition (CO₂, CH₄) extending back ~800,000 years. Oxygen isotope ratios (δ¹⁸O) serve as precise temperature proxies.
Examples in the real world
Antarctic Vostok and EPICA ice core records proving tight historical correlation between atmospheric CO₂ and global temperature.