Geological record of tsunami inundations in Pantano Morghella (south-eastern Sicily) both from near and far-field sources

Abstract

Abstract. Analysis of tsunami deposits from the Pantano Morghella area provided geological evidence for two inundations occurred along the south-eastern Ionian coast of Sicily. Pantano Morghella is a large pond characterised by a finegrained sedimentation indicating a low-energy depositional environment. Two anomalous yellow sandy layers found at different depths indicate the occurrence of high-energy marine inundations. We studied sedimentological and paleontological features of the anomalous deposits as well as their spatial distribution observing the following properties: different facies with respect to the local stratigraphic sequence; erosive bases, rip-up clasts and broken elements testifying violent deposition mechanisms; macro and micro fauna of marine environment; relatively constant thickness throughout most of the depositional zone with thinning at the distal end; large sand sheets that extend inland. These observations, jointly with their infrequency in the sedimentary record and the age indicating a fast deposition, provided strong evidence for tsunami inundations. Correlations between anomalous layers and historical tsunamis are supported by radiocarbon and OSL dating results. The younger deposit is likely due to the 1908 near-source tsunami, whereas the flooding of the oldest event is most likely associated with a far and large source, the Crete 365 AD earthquake.

Geological evidence for paleotsunamis along eastern Sicily (Italy): an overview

“…An extended discussion about this issue can be found in Weiss and Bahlburg (2006), Morton et al (2007), and Smedile et al (2011). In most of the cases, a storm source for the marine deposits found Gerardi et al, 2012). Mascali, Catania and Augusta were also affected by the 1329, 1818, 1542 and 1990 local tsunamis (wavy symbol), respectively (see Table 1).…”

“…Published data from the co-authors of this work are used to compile a homogeneous and integrated history of tsunami inundations in eastern Sicily Barbano et al, 2009De Martini et al, 2010;Smedile et al, 2011;Gerardi et al, 2012). Only in the discussion chapter, will we also integrate data from other authorships (Scicchitano et al, 2007(Scicchitano et al, , 2010.…”

“…in our inland cores could be excluded because the sampling sites presented in this work are located at a greater distance from the coastline with respect to the maximum calculated storm inundation distance of about 40-60 m Gerardi et al, 2012). In fact, in order to avoid the area of influx of storm waves (Morton et al, 2007) that often coincide with a zone of erosion/bypass by tsunamis (Gelfenbaum and Jaffe, 2003), the sites selected for coring are located at a minimum distance of 150-200 m from the present shoreline.…”

“…Today, the only potential connection to the sea is through an artificial narrow channel cut at the beginning of the 20th century for saltpan works. Gerardi et al (2012) dug 40 cores down to a maximum depth of 5.8 m and at a maximum distance of 1200 m from the sea ( Table 2). The pond is characterised by a lagoonal finegrained stratigraphic sequence dominated by clay and siltyclay deposits.…”

“…For example, following the 2011 tsunami in Japan, sediments including marine debris were found even up to 3 km inland (Goto et al, 2011). This debris is taken away from the sea bottom and from the shore by the waves approaching and inundating the coast and, because of the decreasing wave energy, deposited inland.…”