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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. 

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 focus of the discussion will be on the debris and vessel transport capacity of the tsunami induced currents in ports and harbors. The tsunami events in the past 15 years proved that understanding these processes within the port/harbor basin has paramount importance in safety, recovery and the long-term resilience planning of the facilities; as all of these depend on the ability of structures or infrastructure to resist damage and the capability of harbors to become functional after the event. This endeavor requires an accurate representation of the flow field around the floating objects. Particularly, when the size of an average container ship is considered among with its’ fairly high draft to depth ratio, the interaction between flow and the vessels gets stronger. Therefore, in this study, the developed numerical tool, which is coupled with a 2HD nonlinear shallow water model, takes the interaction between the flow and the objects into account, and provides accurate results in a computationally efficient way. We will also present example simulation results of a numerical modelling study aimed at providing the quantitative guidance on maritime tsunami hazards in ports and harbors. This information can be used in pre-disaster recovery planning with the identification of the safe mooring spots or where the debris will likely accumulate after future tsunamis. Whilst the harbor’s ability to resist damage is a function of reducing the exposure to hazardous conditions as well as the maintaining/upgrading the structures/infrastructure within the harbors. 

The retreat of glaciers in response to global warming has the potential to trigger landslides in glaciated regions around the globe. Landslides that enter fjords or lakes can cause tsunamis, which endanger people and infrastructure far from the landslide itself. Here we document the ongoing movement of an unstable slope (total volume of 455 × 10⁶m³) in Barry Arm, a fjord in Prince William Sound, Alaska. The slope moved rapidly between 2010 and 2017, yielding a horizontal displacement of 120 m, which is highly correlated with the rapid retreat and thinning of Barry Glacier. Should the entire unstable slope collapse at once, preliminary tsunami modeling suggests a maximum runup of 300 m near the landslide, which may have devastating impacts on local communities. Our findings highlight the need for interdisciplinary studies of recently deglaciated fjords to refine our understanding of the impact of climate change on landslides and tsunamis.