Overview

• Researchers reconstructed individual wet- and dry-season rainfall between 871 and 1021 CE by analysing oxygen-isotope layers in a stalagmite from Grutas Tzabnah.
• The climate record reveals eight multi-year wet-season droughts of at least three years, including a 13-year event circa 929–942 CE—the longest in the sequence.
• Drought intervals correspond with archaeological signs of sociopolitical stress, such as halted monument construction at Chichén Itzá and settlement shifts across the northern Yucatán.
• A roughly 50-year stalagmite non-growth gap from 1021 to 1070 CE remains ambiguous, with researchers debating whether it reflects extreme drought or intensified rainfall and mineral dissolution.
• Authors call for additional speleothem sampling and cross-proxy comparisons to resolve local resilience strategies and refine the timing and impact of climate-driven change.