For anyone wondering how earthquakes are possible here in the copenhagen area when it isn't on a tectonic plate border
Think of the Earth's crust like a long wooden ruler.
If you stand on both ends of a wooden ruler and push hard toward the middle, you are applying force at the edges. But the ruler doesn't break under your hands, it snaps right in the middle where the wood is naturally a little weaker.
That’s exactly what just happened. The borders of our tectonic plate (thousands of kilometers away in Iceland and the Mediterranean) are constantly pushing and squeezing. That pressure traveled quietly through the solid rock until it hit an ancient, deeply buried "crack" right under Denmark, a place called the Sorgenfrei-Tornquist Zone and caused it to instantly snap. So the way this earthquake occured isn't the same as we see in places like Turkey or California, which is a result of the plates shifting and smashing into each other.
A tiny bit of rare planetary history right under our feet today. This earthquake was only a 4.2 on the ricter scale and it still felt terrifying even if it was only for a second, I cannot imagine how much more terrifying it would be in areas with frequent earthquakes.