Paleoenvironmental Change in Arid Andean Regions

The arid regions of the Central Andes, encompassing the hyperarid core of the Atacama Desert, the high‐elevation Altiplano and the semi‐arid forelands, preserve a rich archive of past environmental dynamics. These landscapes record the onset and intensification of aridity over the late Cenozoic, punctuated by episodic wetter phases during interglacial intervals. Proxy records—from isotopic signatures in leaf waxes and diatom assemblages in sediment cores to tree‐ring chronologies and surface exposure dating—reveal that orbital parameters (precession, obliquity) modulate moisture delivery by shifting the subtropical jet, the South American Summer Monsoon and the southern westerly winds. High‐resolution reconstructions document centennial to millennial‐scale variability tied to ENSO and Pacific sea‐surface temperatures, while palaeoglacial landforms mark alternating phases of glacial advance and retreat. Understanding these controls is critical for anticipating water availability in a warming world, for conserving unique biota sustained by fog and for informing sustainable resource management in one of Earth’s driest environments.

Research from Nature Portfolio

Recent isotopic analysis of deuterium in leaf wax biomarkers from marine sediment cores off central Chile has demonstrated that orbital precession peaks enhance tropical moisture transport to mid‐latitudes, whereas obliquity modulates southern westerly wind strength. This dual control explains the timing of the last glacial moisture maximum and the early Holocene moisture minimum. In parallel, a multi‐disciplinary investigation of a drill core from an endorheic basin in the Coastal Cordillera shows that the central Atacama, although persistently hyperarid, experienced modest yet significant wetter intervals during Marine Isotope Stages 7 and 5, with evidence for ephemeral lacustrine conditions. These records challenge the notion of a uniformly dry desert and highlight asynchronous responses between the coastal and Altiplano sectors to global and regional climate forcings.

Paleoenvironmental Change in Arid Andean Regions publication trend

The graph below shows the total number of articles in paleoenvironmental change in arid andean regions across all publications each year (not limited to Nature Index journals).

Technical terms

Deuterium: A stable heavy isotope of hydrogen used to trace past hydrological processes via its ratio to protium (¹H).

Leaf wax biomarkers: Long‐chain lipids preserved in sediments, originating from terrestrial plants, employed to reconstruct past moisture and vegetation changes.

Orbital modulation: The influence of variations in Earth’s orbital parameters (precession, obliquity, eccentricity) on climate systems and moisture distribution.

Endorheic basin: A closed drainage system that retains water without external outflow, often forming ephemeral lakes in arid settings.

Marine Isotope Stage (MIS): Alternating warm (odd‐numbered) and cold (even‐numbered) periods derived from oxygen isotope records of marine sediments, indicating global ice volume changes.

Dendroclimatology: The reconstruction of past climate using the width, density or isotopic composition of annual tree rings.

References

1. Orbital modulation of subtropical versus subantarctic moisture sources in the southeast Pacific mid-latitudes. Nature Communications (2024).
2. “Climatic fluctuations in the hyperarid core of the Atacama Desert during the past 215 ka”. Scientific Reports (2019).
3. Precipitation changes in the South American Altiplano since 1300 AD reconstructed by tree-rings. Climate of the Past (2012).
4. Timing and extent of late pleistocene glaciation in the arid Central Andes of Argentina and Chile (22°-41°S). Cuadernos de Investigación Geográfica (2017).
5. Isotopic characteristics and paleoclimate implications of the extreme precipitation event of March 2015 in northern Chile. Andean Geology (2018).