The 1956 Greek tsunami recorded at Yafo, Israel, and its numerical modeling

Abstract

[1] A record of a tsunami event riding on the usual tide signal was recorded by a floating-type tidal gauge installed in the port of Yafo, Israel. The tsunami was triggered by an earthquake in the Aegean Sea on 9 July 1956. This paper presents a retrieval of tsunami waves from the record. At the first stage of the study an attempt had been undertaken to reproduce the 1956 tsunami assuming a coseismic nature of its generation source. Although these simulations resulted in tsunami waves with their amplitude close to that obtained from the record measured at Yafo, they did not contain significant spectral energy components with periods of $15 min as appear in the spectra of 1956 tide-gauge records. When landslide movement, triggered by the main shock and/or by the largest aftershock, is suggested as a source of these tsunami waves, the spectra of the resulted marigram obtained in the proximity to Yafo contain harmonics with frequencies very close to those measured. This corroborates the landslide nature of the tsunamigenic source responsible for generation of higher-frequency (relative to the tidal waves) energy components. The peak periods determined via spectral analysis of the recent tide-gauge records (1 year and longer) in the absence of tsunami events vary from 50 to 60 min. Similar periods have been revealed in a special numerical study dealing with longwave propagation toward the coast of Israel, thus confirming that their origin is related to continental shelf resonance. These resonance periods differ significantly from those found for the 1956 tsunami.

Rapid forecasting of tsunami runup heights from 2-D numerical simulations

“…Previous analyses of tsunami characteristics have used the shallow-water model with a no-flux boundary condition at a depth of 5-10 m on the shore (Titov and Synolakis, 1998;Sato et al, 2003;Choi et al, 2003;Ioualalen et al, 2007;Schuiling et al, 2007;Zaitsev et al, 2009;Beisel et al, 2009). In this model, runup heights are determined using simplified formulae of the 1-D, analytic theory of long-wave runup for a fixed shape of an incident wave, whether a sine wave or a solitary wave (Choi et al, 2002a;Ward and Asphaug, 2003).…”

A Review of Potential Tsunami Impacts to the Suez Canal

“…The methodology discussed here is predicated neither on our interpretations of tsunamigenesis nor on our computer modeling of tsunami wave transmission, although other researchers' efforts at simulations of numerical tsunami propagation are reported (e.g., Beisel et al, 2009;Fine et al, 2003;Salamon et al, 2008;Sintubin, 2011;Sørensen et al, 2012;Yalçiner et al, 2007;Zaytsev et al, 2008). Instead, our analyses depend on an approach that integrates known facts or documented events that are believed to have taken place in the past, even though archeoseismological data and other kinds of interpretations of geological events may not be in perfect agreement.…”

“…Although no computer analyses of potential tsunamis that could impact the eastern Nile Delta, including the two northernmost entrances to the Suez Canal, were conducted, other researchers have initiated mathematical scenarios of interest (e.g., Beisel et al, 2009;Pareschi, Boschi, and Favalli, 2006;Salamon, 2010;Salamon et al, 2008;Sørensen et al, 2012;Tinti et al, 2005;Yalçiner et al, 2007;Zaytsev et al, 2008). Tinti et al (2005), for example, ran several computer simulations, one of which, their ''eastern Hellenic Arc scenario,'' is relevant to a potential tsunami entering the Suez Canal.…”

Israel's Exodus in Transdisciplinary Perspective

“…The 1956 tsunami (marked red in Fig. 9.5a) in the Aegean Sea (Ambraseys 1960) which was triggered by a combined mechanism of an earthquake and a submarine landslide near the Santorini area (Perissoratis and Papadopoulos 1999;Beisel et al 2009) does demonstrate that tsunamis may leak out of the ring of islands around the Aegean Sea into the Mediterranean (recorded in Jaffa, Goldsmith and Gilboa 1986). Yet in doing so, the wave heights of such tsunamis are attenuated considerably, as is shown by our modeling (Table 9.1).…”