At 11.51 AM today (17 Jan 2018) there was an earthquake of magnitude 4.9 roughly 80km east of Lisbon.
The Richter scale is logarithmic. This means every time you go up a single unit, the quake is ten times more powerful. So a 4.9 quake is 10 times stronger than a 3.9.
The epicentre was at Arraiolos, near to Évora, a UNESCO World Heritage Site.
The tremor was reported to be felt over a wide area, including Badajoz in Spain, and Faro. All I can say is that we felt nothing here.
At this moment, there are no reports of casualties.