1931 Dogger Bank earthquake
1931 CE.
Shown on the map at 54.147°, 1.850°.
The Dogger Bank earthquake of 1931 is the strongest earthquake recorded in the United Kingdom since measurements began. It had a magnitude of 6.1 on the Richter scale, and it caused a shaking intensity of VI (Strong) to VII (Very strong) on the Mercalli intensity scale. The location of the earthquake in the North Sea meant that damage was significantly less than it would have been had the epicentre been on the British mainland.
Text from the Wikipedia article 1931 Dogger Bank earthquake, licensed CC BY-SA 4.0.