[1] The barotropic and baroclinic nontidal circulations of the Ría de Vigo (NW Spain) are studied using the three-dimensional finite difference model HAMSOM (Hamburg Shelf Ocean Model). The external forcing acting on the system includes winds, freshwater inflow in the inner part of the ria and all over its surface, and heat exchange with the atmosphere. Modeled velocity is compared with data from an AANDERAA DCM12 acoustic Doppler current meter at one site of the ria, and predicted salinity and temperature fields contrasted with SEABIRD conductivity-temperature-depth data along the main channel of the ria. All predicted current, salinity, and temperature fields are in good agreement with experimental data. A new residual circulation pattern of the Ría de Vigo and its dependence on coastal winds is described. According to this pattern the typical estuarine two-layer circulation overlays in the outer part of the ria with a lateral circulation, resulting in a three-dimensional dynamics. The lateral circulation is induced by interaction between the southward (northward) alongshore coastal jet associated with upwelling (downwelling) winds and the topographic configuration of the ria.

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HighlightsCanyon incision, width and orientation modify tsunami wave arrival and run-up.Shoreward of a canyon head, tsunami height diminishes with increased incision.At both sides of the canyon, tsunami wave height increases.The presence of a canyon incised very close to the coast can produce edge waves. We analyse the variations produced on tsunami propagation and impact over a straight coastline 20 because of the presence of a submarine canyon incised in the continental margin. For ease of 21 calculation we assume that the shoreline and the shelf edge are parallel and that the incident wave 22 approaches them normally. A total of 512 synthetic scenarios have been computed by combining the 23 bathymetry of a continental margin incised by a parameterised single canyon and the incident 24 tsunami waves. The margin bathymetry, the canyon and the tsunami waves have been generated 25 using mathematical functions (e.g. Gaussian). Canyon parameters analysed are: (i) incision length into 26 the continental shelf, which for a constant shelf width relates directly to distance from the canyon 27 head to the coast, (ii) canyon width, and (iii) canyon orientation with respect to the shoreline. 28Tsunami wave parameters considered are period and sign. The COMCOT tsunami model from Cornell 29University was applied to propagate the waves across the synthetic bathymetric surfaces. Five 30 simulations of tsunami propagation over a non-canyoned margin were also performed for reference. 31 32The analysis of the results reveals a strong variation of tsunami arrival times and amplitudes reaching 33 the coastline when a tsunami wave travels over a submarine canyon, with changing maximum height 34 location and alongshore extension. In general, the presence of a submarine canyon lowers the arrival 35 time to the shoreline but prevents wave build-up just over the canyon axis. This leads to a decrease in 36 tsunami amplitude at the coastal stretch located just shoreward of the canyon head, which results in 37 a lower run-up in comparison with a non-canyoned margin. Contrarily, an increased wave build-up 38 occurs on both sides of the canyon head, generating two coastal stretches with an enhanced run-up. 39These aggravated or reduced tsunami effects are modified with (i) proximity of the canyon tip to the 40 coast, amplifying the wave height, (ii) canyon width, enlarging the areas with lower and higher 41 maximum height wave along the coastline, and (iii) canyon obliquity with respect to the shoreline and 42 shelf edge, increasing wave height shoreward of the leeward flank of the canyon. Moreover, the 43 presence of a submarine canyon near the coast produces a variation of wave energy along the shore, Tsunami; multi-scenario; numerical simulation; submarine canyon 54 55

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