Tree Rings and Volcanic Eruptions

 Counting the number of tree rings and observing the relative growth for each ting can give an age for when something happened. However, it may not be that simple. Some climate cooling caused by past volcanic eruptions may not be evident in tree-ring reconstructions of temperature change, because large enough temperature drops lead to greatly shortened or even absent growing seasons, according to climate researchers who compared tree-ring temperature reconstructions with model simulations of past temperature changes. Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings.  By accounting for these various effects in the tree growth model, the researchers were able to reproduce the reduced and smeared cooling seen in the actual tree-ring temperature reconstruction, including the near absence and delay of cooling following a massive eruption in 1258