Fig. 2: Relationship between uplift gradient and normalised divide location.

a–d Selected model results of divide position in response to asymmetric uplift. Topographies of asymmetric mountain range generated by the TopoToolbox Landscape Evolution Model (TTLEM⁴⁰) in response to a linear gradient in uplift rate from 0.5 mm/year at the bottom edge to a 0.5 mm/ year, b 3 mm/year, c 6 mm/year, and d 10 mm/ year at the top edge. Black lines are the main drainage divides of mountain ranges. A run time of 300 Myr (million years) is sufficient to attain steady state from the initial topography in all cases (Supplementary Fig. 6). e Relationship between uplift gradient and steady-state divide location. The data points denote the mean values with one standard deviation. Each data point of Southern Taiwan and Northeastern Sicily is calculated from three values (see “Methods”). For numerical simulation, 2000–3000 values are used to calculate divide location, depending on the length of the main drainage divide. Grey shading represents the 95% confidence range of the model results. Uplift rates of Northeastern Sicily integrated since the Late Pleistocene (~125,000 years) are calculated from data in ref. ⁴⁷. Uplift rates of Southern Taiwan are calculated from decadal-scale GPS data. Source data are provided as a Source Data file.