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Augmented reality (AR) is a technology that integrates 3D virtual objects into the physical world in real-time, while virtual reality (VR) is a technology that immerses users in an interactive 3D virtual environment. The fast development of augmented reality (AR) and virtual reality (VR) technologies has reshaped how people interact with the physical world. This presentation will outline the results from two unique AR and one Web-based VR coastal engineering projects, motivating the next stage in the development of the augmented reality package for coastal students, engineers, and planners.

 

SUMMARY On 2020 May 2, an Mw = 6.6 earthquake struck about 63 km south of Ierapetra in Crete, Greece. The earthquake generated a small tsunami which agitated local harbours. We studied this event in the context of earthquakes with seismic records in 1908, 1910, 1923, 1952, 2009 and 2013, all of similar magnitudes located south of Crete. Based on an energy-to-moment ratio, our analysis suggests that this event was neither slow nor fast, hence appropriate for using scaling laws to infer seafloor deformations. We also performed a field survey, three days after the event and present field observations from seven locations, including the island of Chrisi, where our highest measurement of 0.95 m was located. Runup along the coast of southern Crete ranged from 0.24 to 0.87 m. One tide gauge record is available for this event, and we did image analysis to obtain accurately timed water surface elevations from eyewitness videos and images. We undertook high-resolution hydrodynamic simulations using published moment tensor solutions to identify the source of the tsunami. Simulations were performed with two models, MOST (a nonlinear shallow water model) and COULWAVE (a Boussinesq-type model), to infer how different approximations of the parent equations of motion affect predictions for tsunamis of this size, which are fairly common in the Eastern Mediterranean and routinely trigger Tsunami Service Providers to issue warning messages. Based on the inter-model comparison, we conclude that the shallow-water equations are adequate in modelling this event at the distances considered, suggesting that such codes can be used to infer the tsunami source and to estimate tsunami impacts. Last, our field work revealed lack of knowledge of tsunami hazards, as most eyewitnesses remained near the waterfront, filming the associated unusual water motions instead of taking shelter on high ground. 

For many practical and theoretical purposes, various types of tsunami wave models have been developed and utilized so far. Some distinction among them can be drawn based on governing equations used by the model. Shallow water equations and Boussinesq equations are probably most typical ones among others since those are computationally efficient and relatively accurate compared to 3D Navier-Stokes models. From this idea, some coupling effort between Boussinesq model and shallow water equation model have been made (e.g., Son et al. (2011)). In the present study, we couple two different types of tsunami models, i.e., nondispersive shallow water model of characteristic form(MOST ver.4) and dispersive Boussinesq model of non-characteristic form(Son and Lynett (2014)) in an attempt to improve modelling accuracy and efficiency.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/cTXybDEnfsQ 

The abstract is based on the project of "extended reality" for effective communication of hazards from extreme coastal events, such as tsunamis and hurricanes. The project attends to use augmented reality (AR) and mixed reality (MR) to allow, for example, a coastal resident to see a digital tsunami crashing onshore and bulldozing through a community, all while standing on their beach or in their driveway. This type of experience provides an emotional impact and long-lasting memory that will guide future planning decisions and proactivity. In this abstract, we focus on applying mobile augmented reality (AR) to a tsunami simulation system and creating this digital extreme event experience. The tsunami modeling studies use the methods and models described in Tavakkol & Lynett (2017), Lynett et al. (2017) and Lynett & Tavakkol (2017).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/TD4qI5QdAEc 

This paper describes a two-dimensional scalar transport model solving advection-diffusion equation based on GPU-accelerated Boussinesq model called Celeris. Celeris is the firstly-developed Boussinesq-type model that is equipped with an interactive system between user and computing unit. Celeris provides greatly advantageous user-interface that one can change not only water level, topography but also model parameters while the simulation is running. In this study, an advection-diffusion equation for scalar transport was coupled with extended Boussinesq equations to simulate scalar transport in the nearshore.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/aHvMmdz3wps 

The time series of free surface elevation measured in and outside the shadow zone were compared and analyzed in the time-frequency domain by employing the continuous wavelet transform. Regardless of the conditions of the ERF wave in the shadow zone, an increase in magnitude of energy is noticeable not only in the peak frequency within a range of approximately 0.8 to 1 Hz but also in the low-frequency range of around 0.1 Hz corresponding to second up to third crest of the leading wave. To determine the effective frequency of ERF waves and evaluate their runup characteristics, we applied a new method of describing the ERF wave, which consists of linear superposition of two solitary waves. As a result, the ERF waves show the same trend in runup characteristics as for solitary waves. 

Testing took place from January to June 2019 and included natural and built environment tests with an emphasis on obtaining loading data for a 10x10 array of structures in the inundation zone. Bare earth tests were conducted first to get baseline velocity and wave height data. Then, the array of structures was added to the inundation zone. In addition to the same velocity and wave height sensors used in the bare earth experiments, some of the structures recorded pressures, moments, and loads. Debris in the form of wood blocks was added to both the bare earth and array tests to see how it changed the results. Sea walls are often used as a form of protection from waves and storm surge, so a wall of varying lengths was added to the array tests. These 5 main basin setups correspond to the 5 events below. Many different conditions were tested for each of these experiments. The "ALL_Experimental_Trials" table in the Sensor Information Section describes the conditions of every trial of the experiment and must be used to understand the data in every event folder. Please see the report for details as well.