Analysis of the 2019 Mw 5.8 Silivri earthquake ground motions
- The main Marmara fault (MMF) extends for 150 km through the Sea of Marmara and forms the only portion of the North Anatolian fault zone that has not ruptured in a large event (Mw >7) for the last 250 yr. Accordingly, this portion is potentially a major source contributing to the seismic hazard of the Istanbul region. On 26 September 2019, a sequence of moderate-sized events started along the MMF only 20 km south of Istanbul and were widely felt by the population. The largest three events, 26 September Mw 5.8 (10:59 UTC), 26 September 2019 Mw 4.1 (11:26 UTC), and 20 January 2020 Mw 4.7 were recorded by numerous strong-motion seismic stations and the resulting ground motions were compared to the predicted means resulting from a set of the most recent ground-motion prediction equations (GMPEs). The estimated residuals were used to investigate the spatial variation of ground motion across the Marmara region. Our results show a strong azimuthal trend in ground-motion residuals, which might indicate systematically repeating directivityThe main Marmara fault (MMF) extends for 150 km through the Sea of Marmara and forms the only portion of the North Anatolian fault zone that has not ruptured in a large event (Mw >7) for the last 250 yr. Accordingly, this portion is potentially a major source contributing to the seismic hazard of the Istanbul region. On 26 September 2019, a sequence of moderate-sized events started along the MMF only 20 km south of Istanbul and were widely felt by the population. The largest three events, 26 September Mw 5.8 (10:59 UTC), 26 September 2019 Mw 4.1 (11:26 UTC), and 20 January 2020 Mw 4.7 were recorded by numerous strong-motion seismic stations and the resulting ground motions were compared to the predicted means resulting from a set of the most recent ground-motion prediction equations (GMPEs). The estimated residuals were used to investigate the spatial variation of ground motion across the Marmara region. Our results show a strong azimuthal trend in ground-motion residuals, which might indicate systematically repeating directivity effects toward the eastern Marmara region.…
| Author details: | Elif Türker, Fabrice CottonORCiDGND, Marco PilzORCiD, Graeme WeatherillORCiD |
|---|---|
| DOI: | https://doi.org/10.1785/0220210168 |
| ISSN: | 0895-0695 |
| ISSN: | 1938-2057 |
| Title of parent work (English): | Seismological research letters |
| Subtitle (English): | evidence of systematic azimuthal variations associated with directivity effects |
| Publisher: | Seismological Society of America |
| Place of publishing: | Boulder, Colo. |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2022/01/19 |
| Publication year: | 2022 |
| Release date: | 2024/01/12 |
| Volume: | 93 |
| Issue: | 2A |
| Number of pages: | 13 |
| First page: | 693 |
| Last Page: | 705 |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
| Peer review: | Referiert |
