Lottie! Hello! 🙂 Tsunamis are created when a huge event occurs that displaces water in the ocean. This could be a tectonic plate moving (the Earth’s crust is made up of HUGE slabs of rock called tectonic plates), an underwater volcano erupting OR a meteorite hitting the sea and creating a huge wave!
The UK is very nicely protected from tsunamis by Europe, so don’t expect any to hit you!