GNGTS 2022 - Atti del 40° Convegno Nazionale

72 GNGTS 2022 Sessione 1.1 The estimated recurrence interval ofMw=6 earthquakes, in the order of 10 2 years, decreases to 10 3 years for Mw~7 earthquakes (Galli, 1999; Begin et al. , 2005). Historical earthquake catalogues report strong damage during the years 303, 363, 551, 749, 1202, 1759, and 1837 AD. The earthquake of January 18th, 749 was a large-magnitude event, with extensive damage centered around the northern part of the Jordan valley. This caused the destruction of Tiberias and Beit-She’an, and surface ruptures on the western shore of the SoG (Marco et al. , 2003). The earthquake of May 20, 1202 is probably the strongest affecting this region in historical times (Ambraseys and Melville, 1988). The earthquake of January 1st, 1837 also caused severe damage in Tiberias and Safed, again along the western shore of the SoG. During this event, seiching of the lake was reported, and largest macroseismic intensities were observed W of the SoG (Ambraseys, 1997). The region is characterized by natural springs with ground waters in a wide range of temperatures and chemical compositions escaping from tectonic structures. Geochemical analyses show outgassing of mantle-derived fluids suggesting deep connections to the mantle at a regional scale. At several thermal springs and wells, the emerging waters are gas-rich, and dissolved volatiles contain a mantle-derived component (e.g., Torfstein et al. , 2013, Inguaggiato et al. , 2016); it has been observed that this component progressively decreases from N to S along the DSF system (Torfstein et al. , 2013). All these occurrences, and the relatively easy accessibility due to a shallow-water environment not requiring complex equipment’s and technologies, make the Sea of Galilee an interesting site to study relationships between the seismic cycle and the presence/circulation of fluids in the substratum, and to design seafloor observatory experiments to study this interplay during seismic and interseismic phases. References Ambraseys, N.N., and Melville, C.P. (1988). An analysis of the eastern Mediterranean earthquake of 20 May 1202, in Lee, W. K. H., Meyers, H., and Shimazaki, K., eds., Historical Seismograms and Earthquakes of the World: San Diego, California, Academic Press, p. 181-200. Ambraseys, N.N. (1997). The earthquake of 1 January 1837 in southern Lebanon and northern Israel. Annali di Geofisica, 4, 923-935. Ben-Avraham, Z., Ten-Brink, U., Bell, R., Reznikov, M. (1996). Gravity field over the Sea of Galilee: evidence for a composite basin along a transform fault. J. Geophys. Res., 101: 533–544. Galli, P. (1999). Active tectonics along the Wadi Araba-Jordan Valley transform fault. J Geophys Res 104:2777–2796. https://doi.org/10.1029/1998JB900013. Gasperini et al. , (2020). Neotectonics of the Sea of Galilee (northeast israel): implication for geodynamics and seismicity along the Dead Sea fault system. Scientific Reports, 10, 1-17. Haddad et al. (2020). Tectonics of the Dead Sea fault driving the July 2018 seismic swarm in the Sea of Galilee (Lake Kinneret), Israel. Journal of Geophysical Research: Solid Earth, 125, e2019JB018963. Inguaggiato, C., Censi, P., D’Alessandro, W. and Zuddas, P. (2016). Geochemical characterisation of gases along the dead sea rift: Evidences of mantle-co2 degassing. Journal of Volcanology and Geothermal Research, 320: 50-57. Lazar et al. , (2019). Constraints on gas release from shallow lake sediments - a case study from the Sea of Galilee. Geo-Marine Letters, DOI: 10.1007/s00367-019-00588-w. Marco, S., Agnon, A., Ellenblum, R., Eidelman, A., Basson, U. and Boas, A. (1997). 817-year-old walls offset sinistrally 2.1 m by the Dead Sea Transform, Israel: Journal of Geodynamics, v. 24, no. 1-4, p. 11-20. Marco, S., Hartal, M., Hazan, N., Lev, L. and Stein, M. (2003). Archaeology, history, and geology of the A.D.749 earthquake, Dead Sea transform: Geology, v. 31, no. 8, p. 665-668. Marco, S., Rockwell, T., Heimann, A., Frieslander, U. and Agnon, A. (2005). Late Holocene activity of the Dead Sea Transform revealed in 3D palaeoseismic trenches on the Jordan Gorge segment: Earth and Planetary Science Letters, v. 234, no. 1-2, p. 189-205. Torfstein, A., Hammerschmidt, K., Friedrichsen, H., Starinsky, A., Garfunkel, Z. and Kolodny, Y. (2013). Helium isotopes in Dead Sea Transform waters . Chemical Geology, 352: 188-201. Wechsler, N., Marco, S., Klaus-G. Hinzen, K-G., and Hinojosa-Prieto, H. (2018). Historical earthquakes around the Sea of Galilee. In: Hippos-Sussita of the Decapolis, the first twelve seasons of excavations 2000-2011 , Vol. II, ed. M. Eisenberg, Publisher: The Zinman Institute of Archaeology,16-23.