1984 Llŷn Peninsula earthquake
|Date||19 July 1984|
|Depth||20.7 kilometres (13 mi)|
|Areas affected||United Kingdom
|Max. intensity||6 EMS - Slightly damaging|
The 1984 Llŷn Peninsula earthquake struck the Llŷn Peninsula in Gwynedd, north-west Wales on Thursday 19 July 1984 at 06:56 UTC (07:56 BST). It measured 5.4 on the Richter scale, and is the largest known onshore earthquake to occur in the UK since instrumental measurements began. 
The effects were felt throughout Wales, most of England and parts of Ireland and Scotland. There were many reports of minor damage to chimneys and masonry throughout Wales and England, the biggest concentration of damage being in Liverpool, which is located around 65 miles north-east of the epicentre. Minor injuries were also reported in the areas surrounding the epicentral area, and rockslides occurred at Tremadog in Gwynedd. 
- "BGS FAQ What are the largest two instrumental, onshore earthquakes?". BGS. Archived from the original on 9 October 2007. Retrieved 10 October 2007.
- "19 July 1984 Lleyn Peninsula". BGS. Retrieved 10 October 2007.
- "USGS Significant earthquakes of the world 1984". USGS. Archived from the original on 12 October 2007. Retrieved 10 October 2007.
- "Manchester Earthquake Sequence report (Mentions this event)". BGS. Retrieved 10 October 2007.