Last Glacial Maximum equilibrium line altitudes in the circum-Caribbean (Mexico, Guatemala, Costa Rica, Colombia, and Venezuela)

Abstract

Equilibrium line altitude (ELA) estimates for Last Glacial Maximum (LGM) paleoglaciers in Mexico, Guatemala, Costa Rica, Colombia, and Venezuela were determined using the accumulation area balance ratio (AABR), accumulation area ratio (AAR), toe-to-headwall altitude ratio (THAR), and the maximum altitude of lateral moraine (MALM) methods. LGM glacial expansions are chronologically constrained in Mexico, the Mérida Andes of Venezuela, the mountains around Bogotá, Colombia, and the Ruíz-Tolima massif, Colombia. Undated glacial sites are tentatively correlated to dated sites on the basis of similar moraine morphology and weathering characteristics. LGM ELAs are 3400–3950 m in central Mexico, 3544 m for Guatemala, 3477±13 m for Costa Rica, 4104±197 m for the Sierra Nevada de Santa Marta, Colombia, 3480 m for the Ruíz-Tolima region of Colombia, 3345±130 m for the mountains around Bogotá, Colombia, 4151±181 m for the Sierra Nevada de Cocuy, Colombia, and 3576±163 m for the Mérida Andes of Venezuela. As the modern ELA and/or 0 °C isotherm is found at 4900±200 m, LGM ELA depression in the circum-Caribbean region was between 500 and 1625 m.