Spatial Damage Pattern and Structural Vulnerability Assessment of Moderate Magnitude Earthquakes: The 2017–2019 Ayvacık Case Study, Western Anatolia

DOI

https://www.doi.org/10.59256/ijsreat.20260602001

Published In

Volume 6, Issue 2 (2026)

Published Online

March-April 2026

Pages

01-07

Article Type

Original Article

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The 2017 (Mw=5.3) and 2019 (Mw=5.0) Ayvacık earthquakes in northwestern Türkiye generated significant structural damage in rural settlements despite their moderate magnitudes. This study presents a comprehensive empirical damage assessment based on post-earthquake field surveys covering 4740 structures after the 2017 event and 288 structures after the 2019 event. Buildings were classified by structural type and damage grade. Results indicate remarkably high heavy damage ratios for rural masonry buildings. Following the 2017 event, 25.3% of residential buildings and 41.9% of agricultural structures were classified as collapsed or heavily damaged. Similar patterns were observed in 2019, where 43% of residential and 89% of agricultural buildings experienced heavy damage. The spatial distribution of damage reveals strong correlation with epicentral proximity and local site conditions. The findings highlight the structural vulnerability of non- engineered masonry buildings in rural Anatolia under moderate ground shaking levels (MMI V–VI). Damage ratios derived from this dataset provide valuable empirical input for regional vulnerability modeling and seismic risk assessment studies. The Ayvacık earthquake sequence demonstrates that moderate-magnitude earthquakes can produce disproportionately high damage in areas dominated by low-strength masonry construction and inadequate seismic detailing. This study contributes to the development of region-specific vulnerability parameters for rural building stock in western Türkiye and supports improved seismic risk mitigation strategies.