The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

ABSTRACT: The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models' weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning

Energy conscious dwelling design for Ankara

The study aims to develop energy concious dwellings in climatic conditions of Ankara. Since the computer program SUNCODE-PC is used for thermal performance analysis, an hourly climatic data set for an average year has been prepared. Two design proposals are developed and compared; one of them is designed with conventional features and the other is designed energy conciously. Improvement studies are conducted on the enegy concious desig

Tsunamis in the Sea of Marmara - Historical documents for the past, models for the future

More than 30 tsunami events have impacted the coasts of the Sea of Marmara in the past two millennium, clustering in Izmit Bay, the shores of istanbul, Gemlik Bay, the shores of the Kapidak and Gelibolu Peninsulas. With respect to the last well-known tsunami, the Izmit tsunami of 17 August, 1999, available field survey run-up data and marine surveys provide an opportunity to evaluate how these events were triggered. The main purpose of this study is to determine the slope failure potential as a possible tsunamigenic source in the Sea of Marmara by utilising multi-beam bathymetry, shallow and deep seismic reflection data. On the basis of the landslide geomorphology, the generation, propagation and coastal amplifications of tsunamis related to earthquake and slope failure scenarios were tested by using tsunami simulation model TWO-LAYER. The maximum water surface elevations near the shores along the north and south coasts are obtained according to the selected scenarios of tsunami generation by using available data. (C) 2002 Elsevier Science B.V. All rights reserved

Field survey of the 2004 tsunami occurred at Guadeloupe, Lesser Antilles

The strong earthquake (M = 6.3) occurred on 21st November 2004 in the DominicaPassage, between Guadeloupe and Dominica (Lesser Antilles), generated aweak tsunami with maximum amplitude 80 cm on neighbouring islands. Field surveyis conducted on November 27, 2004. Data of the field survey are described. Results ofthe numerical simulations in the framework of the shallow-water theory are in reasonableagreement with observed data

The 30 October 2020 (11:51 UTC) Izmir-Samos Earthquake and Tsunami; Post-Tsunami Field Survey Preliminary Results

A strong earthquake (Mw=6.6 AFAD*, Mw=6.9** KOERI, Mw=7.0 USGS***) of normal faulting striking about E-W occurred on October 30, 2020 (11:51 UTC) in between offshore Seferihisar (Izmir, Turkey) and Samos Island (Greece). The earthquake generated a tsunami that affected an area in the Aegean Coast of Turkey from Cesme Alacati in the northwestern part to Gumuldur coast in the southeastern part. Immediately after the event, a post-event field survey was performed on 31 October and 1 November 2020 by a team of seven people (A.C. Yalciner, G.G. Dogan, E. Ulutas and O. Polat, A. Tarih, E. R. Yapar and E. Yavuz) from METU, Kocaeli University, Dokuz Eylul University and Istanbul Metropolitan Municipality. The Turkey coast survey area covers mainly three parts: i) Alacati and Zeytineli regions in the Northwestern, ii) Sigacik Bay and Akarca region in Seferihisar coast in the North, and iii) Tepecik and Gumuldur regions in the Northeastern with respect to the earthquake epicenter. The team feels deep sorrow and express their condolences to the people for the loss of life and property in Izmir, Turkey and Greece.Unfortunately, the tsunami was not recorded by any tide gauge located along the Turkish Coast of the Aegean Sea. Therefore, findings from the post-event survey have gained much more importance as the main documentation of sea level variations. The main objectives of this survey are to document the tsunami effects along the coast, obtain any available data on the observed coastal amplitudes and inundation extent, take pictures and audiovisual recording before they were cleaned, interview the eyewitnesses and to understand and explain the event in detail.According to the findings in this field survey and eyewitness reports, the most impacted areas were Sigacik Marina, Sigacik Bay and Akarca region located in a 30 km distance to the epicenter in the northern direction. The maximum inundation distance reached 320 m in Akarca, where 20 boats were sunk in a small fishery port, as reported by the head of the port. The flow depth at this location was measured as 1.86 m. There was a splash height of 1.9 m recorded on a vertical wall of a highly damaged house just near the shore. The more to the southeastern coast after Akarca region, the less impacts were observed. There was almost no significant inundation water motion after Gumuldur. The tsunami impacts highly decreased after the cape of v shape peninsula between Tepecik and Gumuldur.In the northeastern part, Alacati and Zeytineli, the maximum inundation was observed along Alacati Azmak measured as 1300 m. The maximum runup was measured as 1.9 m on the palm trees 50 m away from the coastline in Zeytineli region.To summarize, our findings show that in small bays with narrow entrances, the tsunami was much amplified and the impacts on these coast were more severe. The region contains many streams (called Azmak in the local language) in the bays, which increases the potential of tsunami inundation and damage as also experienced in this event. Another important point is the remarkable increase in the awareness of the people who mostly moved away from the shore after noticing the sea withdrawal. However, unfortunately, a victim, who could not resist the strong current generated and died, was reported. After the 2017 Bodrum-Kos tsunami, the Aegean Sea with its high seismic mobility and this event once more reminded considerable tsunami potential in the eastern Mediterranean.</p