Was the 1899 Menderes Valley Earthquake a double earthquake? Historical and paleosismological constraints

► September 20, 1899 earthquake is investigated by means of historical damage data, witnesses and palaeoseismology. ► Bimodal damage and aid distribution patterns are revealed. ► Surface rupture parametres are also discordant with a single-sourced earthquake. ► We proposed double seismic shocks in this earthquake due to fault segmentation.