5 February 2019
Cobre Las Cruces, Spain: another massive mining landslide
Whilst attention has been focused on the events at Brumadinho in Brazil, another massive mining-induced landslide occurred in Spain on 23rd January, this time at the Cobre Las Cruces mine. Manuel Jesús Florencio has an excellent article online about the failure (in Spanish). This is a very big event, with an estimated volume in the order of 15 million cubic metres (i.e. considerably larger than the landslide at Brumadinho). Fortunately, there were no casualties.
Manuel Jesús Florencio’s article includes this image of the aftermath of the landslide:-
A very substantial section of the northwest corner of the mine has collapsed to generate a landslide about 1.3 km in length. You can get a sense of the scale of the landslide by comparing the Google Earth image of the mine prior to failure (this image was collected in June 2016):
With the Planet Labs image of the site after the landslides (this is a Planetscope four band image):-
This is a closer view of the landslide:-
Geotecniafacil.com has a nice article (again in Spanish) about the background to this landslide. It notes that Cobre Las Cruces is the largest open case copper mine in Europe, but that the core deposit is overlain by blue marls that cause may geotechnical problems. It notes that once weathered these materials are extremely weak, with no cohesion and a very low effective friction angle. This is consistent with the failure seen in the images, which seems to have retrogressed a large distance into the slope, implying a low shear plane angle.
Production is expected to be halted for six months, suggesting that this will be an exceptionally expensive event.
Acknowledgement and reference
Thanks to Carlos Jimémez and Joan Rossello for highlighting this event to me.
Planet Team (2019). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com