Tales from the Underground: Speleothem Records of Past Hydroclimate

Geochemical records from speleothems have significantly advanced our understanding of natural climate variability over the last ~600,000 years. Speleothems are sensitive recorders of past changes in hydroclimate because they can be precisely dated and contain multiple hydrologically sensitive geochemical proxies. Oxygen isotope records from speleothems tell us about the timing and mechanisms of past changes in precipitation amount, temperature, atmospheric circulation, and/or global monsoon intensity. Variations in speleothem carbon isotope ratios or trace element concentrations reflect changes in local water balance, vegetation, and karst hydrology. Speleothem paleoclimate records represent a window into the past that can provide crucial information for understanding how anthropogenic climate change and natural climate variability will impact future water resources on Earth.

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Cave and Speleothem Science: From Local to Planetary Scales

Caves occur everywhere on our planet, from the tropics to the high latitudes and from below sea level to alpine settings. Cave morphologies provide clues to their formation mechanisms, and their iconic mineralogical features—stalagmites and stalactites—carry a wealth of paleoenvironmental information encoded in their geochemistry and mineralogy. Recent work demonstrates a striking improvement in our ability to decode these paleoenvironmental proxies, and dramatic geochronological advances enable higher resolution records that extend further back in geologic time. Cave research addresses an ever-increasing range of geoscience problems, from establishing the timing and mechanisms of climate change to uncovering detailed records of geomagnetic field behavior.

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