Fig. 2: δ13C record from Gordion tree rings compared with δ13C and δ18O records from Sofular and Kocain Caves, Turkey, and the period referred to in texts mentioning famine or grain shortage in Hittite lands.
From: Severe multi-year drought coincident with Hittite collapse around 1198–1196 bc
δ13C and δ18O records from Sofular (bottom) and Kocain (top) Caves compared with the Gordion overall combined average z score δ13C time-series, δ13CCorZ, chronology (middle). The Gordion chronology is also represented smoothed with a 28-point Savitzky–Golnay filter (middle). Z-transformed values greater than zero (drier) are highlighted with orange shading above the line and contrasted with green shading for wetter conditions below the line. Dryness increases towards the top of the graph. Bottom, E indicates the End Hattusha–Hittite Kingdom period during the reign of Suppiluliuma II and before Ramesses III year 8. Bottom, out of 9 contemporary texts that refer to famine or grain shortage in Hittite lands20,37, 4 are from the 13th century bc, 3 are undated but also probably originate from the 13th century bc (orange shading), and 2 are from the end of the 13th century bc (red shaded area). The dashed arrows highlight indications of a drying trend in each record.
