https://www.volcanodiscovery.com/it/la-palma/news/141424/La-Palma-volcano-update-Earthquakes-continue-becoming-shallower.html
A small island, part of the Canary Islands chain, off the coast of Spain. The island itself is the very top of a large undersea volcano, sort of like the Hawaiian chain.
Earthquake frequency has spiked up recently, and the quakes are getting progressively shallower. This likely indicates magma movement upwards within the mountain. If a significant eruption occurs, it’s fairly likely that a large section of the western shore of the island will slump into the ocean (sort of how the side of Mount St Helens collapsed during it’s eruption, except way, wayyyy larger). This movement of earth into the ocean will displace several dozen cubic
miles of water within a few seconds. That will create a tsunami that will hit most of coastal Europe with a surge of about 30-90 feet of water, and the east coast of the US, Caribbean islands, and much of the east coast of South America with a surge between 150-400 feet of water. All cities on the eastern seaboard within 30-40 miles of the coast/sea level would be inundated, including DC. It would make the Indonesian tsunami event of 2004 look like a broken water main by comparison.
We’d have about 6 hours warning here.