Modeling of the 1783 Tsunami Event in Scilla Generated by Landslide

In 1783, an event that has gone down in history as the great seismic crisis in Calabria began, during which two major earthquakes occurred, affecting the Calabrian ridge from the Strait to the north. Between 6 and 7 February in Scilla a tsunami occurred that caused the greatest number of victims in Italy: 1500 people. The mechanism that triggered the tsunami was the detachment of a ridge of rock due to a violent earthquake that affected the area; this detachment caused a subaerial landslide which, by sliding, then deposited the rock on the seabed a few kilometers from the coast, immediately generating the tsunami event. The objective of this study is to perform numerical simulations for tsunami events that occurred in history and use models that perform the propagation of a tsunami, using the best possible bathymetric and topographic data and the historical data to compare the validity of the results. In this way, one can obtain the validation of a model that can be used to simulate possible events of this magnitude on the Calabrian coasts and therefore be able to develop a reliable early warning tsunami system; it also has the advantage of perfectly combining computational burdens and the validity of results.

Pre- and Post-Tsunami Depth Changes of Submarine Topography for the Analysis of Submarine Landslide-Induced Tsunami: Proposal of Digitization Method and Application to the Case of the 1923 Great Kanto Earthquake Tsunamis

We first propose and examine a method for digitizing analog data of submarine topography by focusing on the seafloor survey records available in the literature to facilitate a detailed analysis of submarine landslides and landslide-induced tsunamis. Second, we apply this digitization method to the seafloor topographic changes recorded before and after the 1923 Great Kanto earthquake tsunami event and evaluate its effectiveness. Third, we discuss the coseismic large-scale seafloor deformation at the Sagami Bay and the mouth of the Tokyo Bay, Japan. The results confirmed that the latitude / longitude and water depth values recorded by the lead sounding measurement method can be approximately extracted from the sea depth coordinates by triangulation survey through the overlaying of the currently available GIS map data without geometric correction such as affine transformation. Further, this proposed method allows us to obtain mesh data of depth changes in the sea area by using the interpolation method based on the IDW (Inverse Distance Weighted) average method through its application to the case of the 1923 Great Kanto Earthquake. Finally, we analyzed and compared the submarine topography before and after the 1923 tsunami event and the current seabed topography. Consequently, we found that these large-scale depth changes correspond to the valley lines that flow down as the topography of the Sagami Bay and the Tokyo Bay mouth.

Anatomy of a Catastrophe: Reconstructing the 1936 Rock Fall and Tsunami Event in Lake Lovatnet, Western Norway

Rock falls and landslides plunging into lakes or small reservoirs can result in tsunamis with extreme wave run-ups. The occurrence of these natural hazards in populated areas have encouraged a recent sharp increase of studies that aim to mitigate their impact on human lives and assess infrastructure lost. This paper amalgamates in a novel fashion and at an unprecedented detail in situ historic measurements, geological data and numerical modeling of a rock fall event and associated tsunami wave that occurred in Lake Lovatnet (western Norway) in September 1936. Historical records report an event that released ca. 1 million m3 of rocks and debris from Ramnefjellet Mountain at an altitude of 800 m above Lake Lovatnet. The fragmented material plunged into the lake, causing a tsunami that reached a maximum run-up of 74 m and killed 74 people. In fact, the settlements of Bødal and Nesdal were wiped out as a result of the catastrophic wave. Sediments resulting from the 1936 rock fall and associated tsunami were identified in the subsurface of Lake Lovatnet by shallow geophysical investigations and were retrieved using gravity coring equipment. A set of high resolution physical and geochemical measurements were carried out on the cores with the aim of reproducing a highly detailed reconstruction of this catastrophic event in order to better understand and learn about the processes involved. The cores were retrieved in the northwestern sub-basin of the lake and its chronology was constrained by 210Pb and radiocarbon dating. A specially tailored physically based mathematical model was applied to better understand the tsunami event. Integration of the geophysical record, the sedimentological data and numerical modeling provide a comprehensive background to better understand the effects of such event in a deep fjord-like lacustrine basin and to generate information for better mitigation of similar events elsewhere.

PEMAKNAAN VISUAL PERANGKO BENCANA ALAM TSUNAMI BERDASARKAN TEORI DIFFERANCE JACQUES DERRIDA

Bencana alam tsunami yang terjadi di Aceh dan beberapa kota di dunia pada tahun 2004 menyisakan kerugian bukan hanya material melainkan juga psikologi. Banyak bantuan datang dari seluruh Indonesia. PT Pos Indonesia juga berkontribusi untuk membuat suatu kampanye sosial melalui penjualan perangko. Perangko tsunami tersebut pertama kali diterbitkan pada bulan mei 2005. Secara visual, perangko bencana alam tsunami berbeda dengan perangko bencana alam yang juga dikeluarkan oleh PT. Pos Indonesia. Hal ini yang mendorong peneliti untuk melakukan penelitian mengenai pemaknaan perangko utamanya dari cabang dekonstruksi yaitu differance. Kata differance merujuk pada suatu jejak antar sistem tanda. Penelitian ini merupakan penelitian kualitatif. Pengumpulan data dilakukan dengan teknik wawancara kepada penyintas tsunami untuk memperoleh gambaran dan juga persepsi subjektif berdasarkan pengalaman empiris terhadap kejadian tsunami. Teknik Analisis menggunakan pengkodean (coding). Hasil dari penelitian ini adalah adanya pemaknaan dalam sistem kepercayaan, sifat dasar manusia dan juga ketegangan politik yang terjadi pada saat itu.Natural disaster, tsunami, occurred in 2004 in Aceh and several cities in the world inflicted heavy losses not only materially, but also psychologically. A lot of help came from all over Indonesia. PT. Pos Indonesia also made contribution to organize a social campaign by selling stamps. The tsunami stamps were first issued in May 2005. Visually, the tsunami stamps were different from other natural disaster stamps that were also issued by PT. Pos Indonesia. This encouraged the researcher to conduct a research on the meaning of stamps, especially from the branch of deconstruction, which was difference. The term difference refers to a trace between sign systems. This was a qualitative research. Data were collected through interview with tsunami survivors in order to obtain overviews and subjective perceptions based on empirical experience on tsunami event. The analysis technique used was coding. This research found that there were meanings in the belief system, human natures, and political tensions occurred at that time.

Can Submerged Buoys be Reliably Used for Monitoring Tsunamis in the Indian Ocean?

The article proposes a novel and robust Continuously Homing Submerged Autonomous Tsunami Underwater System (CHATUR) in which the buoy is submerged at a depth of 300 m, collecting sea-level data during normal conditions and surfacing during a tsunami event to transmit the event data. By on-demand reliability analysis, a system in the Bay of Bengal requires health monitoring at an interval of 13 days. By offshore experiments and numerical simulations, the configuration increases the tsunami warning time by ~2 min.

ANALYSIS OF TSUNAMI SCOUR AROUND SQUARE STRUCTURES USING A PUMP-DRIVEN FLOW METHOD

Estimation of the maximum scour depth is important for defining the size and depth of building foundations in order to avoid failure during a tsunami event (Jayaratne, et al 2016). Traditionally, tsunami scour has been studied in laboratory experiments that use solitary waves. However, it has been demonstrated that this type of wave does not represent well a real tsunami (Madsen et al, 2008). In addition, results from field surveys are based on the scour depth after the tsunami event, studying only the maximum flow depth, and ignoring other hydrodynamic features such as velocity and wave period, as well as sediment deposition. The main objective of this research is to estimate maximum tsunami scour around rectangular structures as a function of realistic tsunami variables.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/ykb-JyL7lsE

A Neolithic mega-tsunami event in the eastern Mediterranean: Prehistoric settlement vulnerability along the Carmel coast, Israel

Tsunami events in antiquity had a profound influence on coastal societies. Six thousand years of historical records and geological data show that tsunamis are a common phenomenon affecting the eastern Mediterranean coastline. However, the possible impact of older tsunamis on prehistoric societies has not been investigated. Here we report, based on optically stimulated luminescence chronology, the earliest documented Holocene tsunami event, between 9.91 to 9.29 ka (kilo-annum), from the eastern Mediterranean at Dor, Israel. Tsunami debris from the early Neolithic is composed of marine sand embedded within fresh-brackish wetland deposits. Global and local sea-level curves for the period, 9.91–9.29 ka, as well as surface elevation reconstructions, show that the tsunami had a run-up of at least ~16 m and traveled between 3.5 to 1.5 km inland from the palaeo-coastline. Submerged slump scars on the continental slope, 16 km west of Dor, point to the nearby “Dor-complex” as a likely cause. The near absence of Pre-Pottery Neolithic A-B archaeological sites (11.70–9.80 cal. ka) suggest these sites were removed by the tsunami, whereas younger, late Pre-Pottery Neolithic B-C (9.25–8.35 cal. ka) and later Pottery-Neolithic sites (8.25–7.80 cal. ka) indicate resettlement following the event. The large run-up of this event highlights the disruptive impact of tsunamis on past societies along the Levantine coast.