Human caused #earthquake in #Poland yesterday

There was a magnitude 4.5 earthquake in Poland yesterday caused by human activity. No, not that kind, although I have the computers watching for that sort of thing (and in fact can see tremors from the artillery fire in Ukraine). So what caused this one? Well, not nature. Here’s the impact map …

Click to embiggen.

If you look carefully you’ll see something in the middle of the map. Zooming in we can see what it is:

Can also be embiggened via clicking.

It’s the Żelazny Most Reservoir, the largest tailings reservoir and dam in Europe. This was created from copper mining froth (link to a Wikipedia article for those who didn’t study economic geology in school 😛 ). This mine has been in operation since the 1970’s, and as can be seen here is huge. The mining combined with a lot of water pressure means it’s an unstable situation, and there are concerns about the potential environmental impact in case the dam fails.

Natural earthquakes in Poland are rare. Most of the recent earthquakes have been associated with mining activity such as rock bursts (collapses) or like this one due to hydrological stress from tailings lakes. The company that owns the Żelazny Most site (KGHM Polska Miedź S.A.) seems to have been associated with many of the more recent events.