SHCal

SHCal is a radiocarbon calibration curve designed for the Southern Hemisphere. It provides the relationship between radiocarbon ages (in radiocarbon years BP) and calendar ages (cal BP), enabling researchers to convert measured 14C ages of Southern Hemisphere samples into calendar dates. SHCal complements the Northern Hemisphere calibration curve (IntCal), reflecting hemispheric differences in atmospheric 14C levels and carbon cycling.

The SHCal series has undergone several major revisions. SHCal04 (introduced in 2004) established the early southern calibration framework. Subsequent updates, such as SHCal13 and SHCal20, incorporated new datasets from atmospheric measurements, tree rings, corals, and marine records to extend coverage and improve precision. The most recent versions aim to integrate longer time spans and improved treatment of uncertainties, including regional marine reservoir effects (Delta R) relevant to southern waters.

Applications of SHCal encompass archaeology, geology, and paleoenvironments in the Southern Hemisphere. Researchers use SHCal to date charcoal, wood, bone, peat, coral, and other carbon-containing materials. When dating marine samples or specimens affected by reservoir effects, regional corrections (Delta R) are applied alongside the curve. SHCal is commonly used with radiocarbon calibration software such as OxCal and CALIB, and is published in calibration datasets maintained by the radiocarbon community.

In summary, SHCal provides essential calendar-age calibration for radiocarbon dates south of the equator, reflecting hemispheric differences in 14C production and carbon cycling and updated periodically to incorporate new data and methods.