Large earthquakes have the potential to perturb magmatic and hydrothermal systems, yet the extent to which this occurs in Türkiye, one of the most seismically active regions of the Eastern Mediterranean with numerous late Pleistocene-Holocene volcanoes, has not been systematically assessed. In this study, the nationwide spatial relationship between Mw ≥ 5.5 earthquakes (1904–2025) and 10 late Pleistocene-Holocene volcanic centres is examined using the Triggering Index (TRIGI = d/√S), which incorporates fault scaling and offers a physically meaningful measure of earthquake proximity. The rupture length is estimated from Mw-based empirical scaling relationships, and focal depth is incorporated through an additional 3D hypocentral TRIGI calculation. Earthquakes are classified into four scaled-distance classes: very near-field (TRIGI ≤ 5), near-field (5 < TRIGI ≤ 10), intermediate-field (10 < TRIGI ≤ 15), and far-field (TRIGI > 15). The results show that 35 earthquakes (~ 9%) fall within the very near-field, 54 (~ 14%) within the near-field, 50 (~ 13%) within the intermediate-field, and 244 (~ 64%) within the far-field. Thus, although most earthquakes are classified as far-field in scaled-distance terms, a substantial and tectonically coherent subset repeatedly places several Anatolian volcanoes under low to intermediate TRIGI conditions. The strongest low-TRIGI exposure is concentrated mainly around eastern Anatolian volcanoes, especially Süphan and Tendürek, reflecting their location close to high-strain deformation corridors within the Arabia-Eurasia collision zone. Incorporating focal depth slightly increases TRIGI values for some earthquakes but does not change the first-order spatial pattern. No confirmed earthquake-triggered eruption is known from the instrumental period in Türkiye, and low TRIGI values should not be directly interpreted as deterministic evidence for triggering. However, recent GNSS evidence for coseismic deformation around Hasandağ following the 2023 Kahramanmaraş earthquakes demonstrates that volcanic regions can record measurable earthquake-related signals where suitable observations are available. Therefore, integrating TRIGI into rapid-earthquake information systems operated by AFAD and KOERI would provide a practical screening tool for identifying volcanoes that may warrant targeted post-seismic observations and would support the development of systematic volcano monitoring in Türkiye.

Spatial relationship between earthquakes and volcanoes in Türkiye: do large earthquakes wake volcanoes?

期刊论文
发表日期：

2026年7月31日

查看全文

Göksu Uslular

摘要

Large earthquakes have the potential to perturb magmatic and hydrothermal systems, yet the extent to which this occurs in Türkiye, one of the most seismically active regions of the Eastern Mediterranean with numerous late Pleistocene-Holocene volcanoes, has not been systematically assessed. In this study, the nationwide spatial relationship between M_w ≥ 5.5 earthquakes (1904–2025) and 10 late Pleistocene-Holocene volcanic centres is examined using the Triggering Index (TRIGI = d/√S), which incorporates fault scaling and offers a physically meaningful measure of earthquake proximity. The rupture length is estimated from M_w-based empirical scaling relationships, and focal depth is incorporated through an additional 3D hypocentral TRIGI calculation. Earthquakes are classified into four scaled-distance classes: very near-field (TRIGI ≤ 5), near-field (5 < TRIGI ≤ 10), intermediate-field (10 < TRIGI ≤ 15), and far-field (TRIGI > 15). The results show that 35 earthquakes (~ 9%) fall within the very near-field, 54 (~ 14%) within the near-field, 50 (~ 13%) within the intermediate-field, and 244 (~ 64%) within the far-field. Thus, although most earthquakes are classified as far-field in scaled-distance terms, a substantial and tectonically coherent subset repeatedly places several Anatolian volcanoes under low to intermediate TRIGI conditions. The strongest low-TRIGI exposure is concentrated mainly around eastern Anatolian volcanoes, especially Süphan and Tendürek, reflecting their location close to high-strain deformation corridors within the Arabia-Eurasia collision zone. Incorporating focal depth slightly increases TRIGI values for some earthquakes but does not change the first-order spatial pattern. No confirmed earthquake-triggered eruption is known from the instrumental period in Türkiye, and low TRIGI values should not be directly interpreted as deterministic evidence for triggering. However, recent GNSS evidence for coseismic deformation around Hasandağ following the 2023 Kahramanmaraş earthquakes demonstrates that volcanic regions can record measurable earthquake-related signals where suitable observations are available. Therefore, integrating TRIGI into rapid-earthquake information systems operated by AFAD and KOERI would provide a practical screening tool for identifying volcanoes that may warrant targeted post-seismic observations and would support the development of systematic volcano monitoring in Türkiye.