Assessment of tsunami resilience of Haydarpaşa Port in the Sea of Marmara by high-resolution numerical modeling

Turkey is highly prone to earthquakes because of active fault zones in the region. The Marmara region located at the western extension of the North Anatolian Fault Zone (NAFZ) is one of the most tectonically active zones in Turkey. Numerous catastrophic events such as earthquakes or earthquake/landslide-induced tsunamis have occurred in the Marmara Sea basin. According to studies on the past tsunami records, the Marmara coasts have been hit by 35 different tsunami events in the last 2000 years. The recent occurrences of catastrophic tsunamis in the world's oceans have also raised awareness about tsunamis that might take place around the Marmara coasts. Similarly, comprehensive studies on tsunamis, such as preparation of tsunami databases, tsunami hazard analysis and assessments, risk evaluations for the potential tsunami-prone regions, and establishing warning systems have accelerated. However, a complete tsunami inundation analysis in high resolution will provide a better understanding of the effects of tsunamis on a specific critical structure located in the Marmara Sea. Ports are one of those critical structures that are susceptible to marine disasters. Resilience of ports and harbors against tsunamis are essential for proper, efficient, and successful rescue operations to reduce loss of life and property. Considering this, high-resolution simulations have been carried out in the Marmara Sea by focusing on Haydarpasa Port of the megacity Istanbul. In the first stage of simulations, the most critical tsunami sources possibly effective for Haydarpasa Port were inputted, and the computed tsunami parameters at the port were compared to determine the most critical tsunami scenario. In the second stage of simulations, the nested domains from 90 m gird size to 10 m grid size (in the port region) were used, and the most critical tsunami scenario was modeled. In the third stage of simulations, the topography of the port and its regions were used in the two nested domains in 3-m and 1-m resolutions and the water elevations computed from the previous simulations were inputted from the border of the large domain. A tsunami numerical code, NAMI DANCE, was used in the simulations. The tsunami parameters in the highest resolution were computed in and around the port. The effect of the data resolution on the computed results has been presented. The performance of the port structures and possible effects of tsunami on port operations have been discussed. Since the harbor protection structures have not been designed to withstand tsunamis, the breakwaters' stability becomes one of the major concerns for less agitation and inundation under tsunami in Haydarpasa Port for resilience. The flow depth, momentum fluxes, and current pattern are the other concerns that cause unexpected circulations and uncontrolled movements of objects on land and vessels in the sea

Capturing Physical Dispersion Using a Nonlinear Shallow Water Model

Predicting the arrival time of natural hazards such as tsunamis is of very high importance to the coastal community. One of the most effective techniques to predict tsunami propagation and arrival time is the utilization of numerical solutions. Numerical approaches of Nonlinear Shallow Water Equations (NLSWEs) and nonlinear Boussinesq-Type Equations (BTEs) are two of the most common numerical techniques for tsunami modeling and evaluation. BTEs use implicit schemes to achieve more accurate results compromising computational time, while NLSWEs are sometimes preferred due to their computational efficiency. Nonetheless, the term accounting for physical dispersion is not inherited in NLSWEs, calling for their consideration and evaluation. In the present study, the tsunami numerical model NAMI DANCE, which utilizes NLSWEs, is applied to previously reported problems in the literature using different grid sizes to investigate dispersion effects. Following certain conditions for grid size, time step and water depth, the simulation results show a fairly good agreement with the available models showing the capability of NAMI DANCE to capture small physical dispersion. It is confirmed that the current model is an acceptable alternative for BTEs when small dispersion effects are considered

Tsunami hazard in the Eastern Mediterranean and its connected seas: Toward a Tsunami warning center in Turkey

Tsunami mitigation, preparedness and early warning initiatives have begun at the global scale only after the tragic event of Sumatra in 2004. Turkey, as a country with a history of devastating earthquakes, has been also affected by tsunamis in its past. In this paper we present the Tsunami Hazard in the Eastern Mediterranean and its connected seas (Aegean, Marmara and Black Sea) by providing detailed information on historically and instrumentally recorded significant tsunamigenic events surrounding Turkey, aiming to a better understanding of the Tsunami threat to the Turkish coasts. In addition to the review of the Tsunami hazard, we have studied a possible Tsunami source area between Rhodes and SW of Turkey using Tsunami numerical model NAMI DANCE-two nested domains. We have computed a maximum positive amplitude of 1.13 m and maximum negative amplitude of -0.5 m at the Tsunami source by this study. The distribution of maximum positive amplitudes of the water surface elevations in the selected Tsunami forecast area and time histories of water level fluctuations near selected locations (Marmaris, Dalaman, Fethiye and Kas towns) indicate that the maximum positive amplitude near the coast in the selected forecast area exceeds 3.5 m. The arrival time of maximum wave to Marmaris, Dalaman, is 10 min, while that of Fethiye and Kas towns is 15-20 min. The maximum positive amplitudes near the shallow region of around 10 m depth are 3 m (Marmaris), 1 m (Dalaman), 2 m (Fethiye) and 1 m (Kas). Maximum positive amplitudes of water elevations in the duration of 4 h simulation of the Santorini-Minoan Tsunami in around 1600 BC in the Aegean Sea are also calculated based on a simulation performed using 900 m grid resolution of Aegean sea bathymetry with a 300 m collapse of 10 km diameter of Thera (Santorini) caldera. We have also presented the results of the Tsunami modeling and simulation for Marmara Sea obtained from a previous study. Last part of this paper provides information on the establishment of a Tsunami Warning Center by KOERI, which is expected to act also as a regional center under the UNESCO Intergovernmental Oceanographic Commission - Intergovernmental Coordination Group for the Tsunami Early Warning and Mitigation System in the North-Eastern Atlantic, the Mediterranean and Connected Seas (ICG/NEAMTWS) initiative, emphasizing on the challenges together with the future work needed to be accomplished

Lessons Learned from the 2011 Great East Japan Tsunami: Performance of Tsunami Countermeasures, Coastal Buildings, and Tsunami Evacuation in Japan

In 2011, Japan was hit by a tsunami that was generated by the greatest earthquake in its history. The first tsunami warning was announced 3 min after the earthquake, as is normal, but failed to estimate the actual tsunami height. Most of the structural countermeasures were not designed for the huge tsunami that was generated by the magnitude M = 9.0 earthquake; as a result, many were destroyed and did not stop the tsunami. These structures included breakwaters, seawalls, water gates, and control forests. In this paper we discuss the performance of these countermeasures, and the mechanisms by which they were damaged; we also discuss damage to residential houses, commercial and public buildings, and evacuation buildings. Some topics regarding tsunami awareness and mitigation are discussed. The failures of structural defenses are a reminder that structural (hard) measures alone were not sufficient to protect people and buildings from a major disaster such as this. These defenses might be able to reduce the impact but should be designed so that they can survive even if the tsunami flows over them. Coastal residents should also understand the function and limit of the hard measures. For this purpose, non-structural (soft) measures, for example experience and awareness, are very important for promoting rapid evacuation in the event of a tsunami. An adequate communication system for tsunami warning messages and more evacuation shelters with evacuation routes in good condition might support a safe evacuation process. The combination of both hard and soft measures is very important for reducing the loss caused by a major tsunami. This tsunami has taught us that natural disasters can occur repeatedly and that their scale is sometimes larger than expected

Effects of harbour shape on the induced sedimentation

Tsunamis in shallow water zones lead to sea water level rise and fall, strong currents, forces (drag, impact, uplift, etc.), morphological changes (erosion, deposition), dynamic water pressure, as well as resonant oscillations. As a result, ground materials under the tsunami motion move and scour/erosion/deposition patterns can be observed in the region. Ports and harbours as enclosed basins are the main examples of coastal structures that usually encounter natural hazards with small or huge damaging scales. Morphological changes are one of the important phenomena in the basins under short and long wave attack. Tsunamis as long waves lead to sedimentation in the basins, and therefore, in this study, the relation to the current pattern is noticed to determine sedimentation modes. Accordingly, we present a methodology based on the computation of the instantaneous Rouse number to investigate the tsunami motion and to calculate the respective sedimentation. This study aims to investigate the effects of the incident wave period on Antalya Belek region is selected as a case study sedimentation, NAMI DANCE, which solves non-linear shallow water equations. The results showed that the corner points on the bending part of the basin are always the critical points where water surface elevation and current velocity amplify in the exterior and interior corners, respectively

Meteotsunami generation, propagation and amplification

The cause of the occurrence of ebb or abnormal waves which are occasionally observed on the coasts is related to the spatial and temporal changes of atmospheric pressure. Because, low atmospheric pressure leads to static water level rise in a part of the marine area and high atmospheric pressure leads to static water level drop in another zone, water level throughout the entire marine area is deformed. This deformation moves as wave, sometimes amplifies on the shore. Due to the changes of atmospheric pressure, the respective small amplitude long waves propagate along the entire marine area. This type of waves can propagate through long distances and can also be amplified due to resonant effects in the enclosed basins and nearshore/offshore coastal morphology. The investigation of the amplification of the long-period waves which occurred by the spatial and temporal changes of atmospheric pressure is the one of the objectives of this study. For the different types of regular shaped basins, tests are conducted by numerical modeling solving nonlinear shallow water equations. In the tests, basins with flat, triangular, shelf, upward and downward sloping sections are simulated by using high pressure zone propagating with certain velocity (faster, equal or slower than wave velocity). The change in the sea level is calculated and compared with the theoretical outcomes

Numerical Simulation of the Storm Surge at the Sakhalin Island Southern Part on November 15, 2019

Purpose. Investigation of the storm surge in Korsakov in the southern part of the Sakhalin Island on November 15, 2019 and comparison of the results of its numerical simulation with the data of in situ measurements constitute the aim of the article

Storm damage assessment of a port in the Southwestern Black Sea

This paper presents a comprehensive investigation of the storm damage at a commercial port located in the Southwestern Black Sea Region that occurred on January 18–19, 2018. One week after the event, a field survey was conducted at the port focusing on significantly damaged mound breakwaters and protection structures that failed at several sections. A numerical wave modeling study is carried out to estimate the wave characteristics at deep sea, nearshore, and inside the port to assess the observed damage during the field survey. Widely used numerical models WAVEWATCH III, SWAN, and SWASH are utilized using nested computational domains and calibrated based on satellite measurements. As a result, the significant wave height of the storm is estimated as 7.8 m with a peak period of 12.4 s near the port area, approaching mainly from the northwest direction. The damage mechanisms of the mound structures are discussed based on the field observations and the wave modeling studies. The insufficient seaside armor unit sizes and the orientation of the breakwaters are found to be the main reasons for the damage