At https://phys.org/news/2020-07-lava-tubes-exploration-priority-worlds.html … why lava tubes should be a priority when visiting other planets. When magma comes out of the innards of the earth it flows as lava – liquid rock. The process has created some unusual land forms, such as lava tubes. These can be large affairs and several km in length. The Kazamura Cave on Hawaii is 46 miles long. Lava tubes seem to have formed on the moon – and on Mars. Several thousand cave entrances have been catalogued, many of which may be lava tubes. NASA has been busy with a camera. This cave system is not on the moon, or on Mars, but it provides an idea of what a lava tube looks like on the inside.
Meanwhile, it seems tectonic activity is no stranger to northern Europe. At https://phys.org/news/2020-07-new-evidence-of-long-term-volcanic-seismic… … It would seem even northern Europe has an active volcanic and seismic prospect, not least the Eifel region of Germany. In addition, the region between Eifel and the Alps is still seismically active we are assured – although no volcano is about to explode in the near future. This is purportedly due to the land being lifted upwards and stretched apart. GPS data was used in the research. Interesting.