ACentury ago, a tidal surge Venice was submerged to a depth almost one metre. The same wave swept through Genoa two days later, closing roads as well as railway lines. This was not what most people would call a tsunami or tide, but a surge caused by a combination.
Part of the water rise was Directional storm surge, where water builds up in front of strong winds. Storm surge height is dependent on the distance of open waters over which the wind blows. For example, if the sirocco wind of the Sahara blows the Adriatic’s length, it may cause dramatic surges.
Another factor is seicheA large-scale version, or sish, of water moving in a bathtub. Seiches can occur anywhere water is large enough to be enclosed or partially enclosed. With the right wind, these reflected waves could grow larger and oscillate like miniature tides. These are common in Great Lakes, and they produce the tidal effect over several days as described in the 1922 incident.
In 1978, 2008, and 2012, there were less dramatic Adriatic surges. These are a serious threat to Venice, but they are fortunately manageable. The two most recent eventsThe winds were not in the most dangerous direction, and the flooding resulted wasn’t serious.
