Exploring sub-annual to decadal hydroclimate variability and tropical cyclone activity on the northeastern Yucatán peninsula

Disentangling dominant patterns and underlying drivers of hydroclimate variability and tropical cyclone activity in the tropical Americas remains a challenge of paleoclimatology. To explore the potential of speleothem trace metal abundances to close this gap, we study a fast-growing stalagmite from Xplor Cave from Mexico's Yucatán Peninsula. High precision ²³⁰Th/U dating with average uncertainties of 5-6 years combined with annual layer counting confine XPL04’s growth between c. 1590 to c. 1970. Due to exceptionally high growth rates between 1 and 4mm per year, the record allows to assess sub-annually resolved proxy variations from post-Colombian times into the 20^th century.

Laser Ablation ICP-MS trace metal data from speleothem XPL04 indicate pronounced patterns in hydroclimate sensitive elements. For example, increasing Mg/Ca values suggest a significant drying trend along with a rise in hydroclimate variability during the 20^th century. Furthermore, multiannual transition metal changes covary with long-term tropical cyclone activity. Superimposed on that pattern, Cu concentrations and Cu/Ni ratios peak during major hurricane years, with the most pronounced speleothem responses corresponding with the largest events that made landfall at the cave site (the 1933 ‘Tampico’ Hurricane and a 1903 unnamed event).

This preliminary evaluation encourages in-depth analyses of sub-annual to decadal speleothem trace element variations. Future work will include the integration of elemental and isotopic proxies in order to construct a precisely dated multi-proxy record allowing to assess regional hydroclimatic changes on unprecedented timescales.