During the winter of 2013-2014, there was a storm, and in the West of Ireland waves moved a 620 tonne boulder 2.5 metres.
This was just one of over 1000 boulders that moved along Ireland’s coasts during the storms, many of them quite large. Researcher Rónadh Cox said
We had boulders that were north of 100 tonnes, sitting tens of metres above sea level and tens of metres inland of the high tide mark, that got moved several metres, or several tens of metres
Before the storms she and her team had surveyed this section of the coast, so were able to calculate distance of boulder movement after the storms. Now it is quite apparent that the coast is constantly changing even during a single winter. I don’t remember much about the end of 2013-2014, it was a bog-standard winter, but I am now impressed that this level of geological change was possible in the Aran Islands. Rocks even moved on the uplands upon the top of the cliffs, though obviously more movement happened closer to the sea. And all this is in a region that does not experience hurricanes let alone tsunamis.
Even further away from the sea (still on the island of Inishmore) there are rock landscapes where boulders and smaller stones pile up in what appears to be a field of debris created by the ocean. Cox says:
The waves are just surging up these coastal platforms and doing enormous amounts of work at a quarter of a kilometre inland basically
This also gives us a hint of how a greatly disturbed and expanded climate-changed (angry) sea might do to vulnerable coastal areas.