Fig. 1: Proxies of drier to drought climate from three different detrending methods applied to the Gordion tree-ring dataset.
From: Severe multi-year drought coincident with Hittite collapse around 1198–1196 bc
a, Tree-ring record from 1497–797 bc (Methods). The driest 25% of years is shown in orange (other 75% of years in green shading); division indicated by black horizontal line; 28-point Savitzky–Golnay (SG) filter is shown. Instances of 2 or 3 consecutive dry to very dry years at various levels are indicated. There are 3 instances of the driest 6.25% of years occurring consecutively (1494–1492 bc, 1198–1196 bc and 871–869 bc). The grey bar indicates the 12-year period from 1198 to 1187 bc with 3 consecutive years from 1198–1196 bc in the lowest 6.25% of all years and with 6 or 7 years (50–58%) in the lowest 20% of values. GOR, Gordion. b, Close-up of the period 1275–1125 bc, showing annual ARSTAN (ARS) index values (Methods) highlighting those in the lowest 20% and the lowest 6.25% of values.
