Fig. 3 | Nature Communications

Fig. 3

From: Volcanic suppression of Nile summer flooding triggers revolt and constrains interstate conflict in ancient Egypt

Fig. 3

Response to volcanism in Egyptian social indexes. a Dates of the initiation of internal revolts against Ptolemaic rule composited relative to the dates of 16 volcanic eruptions (represented at year 0 on the horizontal axes; years 1–8 then represent the first to eighth years after these eruptions, and years −1 to −8 the first to eighth years before), excluding an 8-year buffer at the start and end of our 305–30 BCE period (Methods section). Dots indicates statistically significant values estimated using Barnard’s exact test (green: P < 0.05, red: P < 0.01, magenta: P < 0.001). Green dashed lines give the 95% confidence threshold also estimated using Barnard’s exact test. Data associated with any secondary eruptions within the compositing window are excluded (Methods section), and remaining data expressed as a fraction of all records to prevent bias. b Same as a, but for the dates of terminations of the “Syrian Wars”, i.e., wars between the Ptolemaic and Seleukid states. c Same as a, but for priestly decrees. d Same as a, but for Demotic language land sales with significance estimated using the 2-sample student’s t-test. Revolt onset dates N = 10; Syrian Wars N = 9; decrees N = 9; land sales N = 84. Eruption years N = 18, and non-eruption years N = 258 (305–30 BCE)

Back to article page