View of a large sinkhole in the vicinity of Mina Alcaparrosa, in Tierra Amarilla, Atacama region. DPA via Europa Press
The mystery about the origin of the gigantic sinkhole that appeared a few weeks ago in Tierra Amarilla (Atacama region), 800 kilometers north of Santiago, is close to being solved by experts in geomechanics.
The hole has been expanding on the land of the Alcaparrosa copper mine of the Ojos del Salado mining company, of the Canadian Lundin Mining, until it reaches 36.5 meters in diameter and 64 meters deep - the height of a 26-meter building. floors-.
The Minister of Mining, Marcela Hernando, assured this week that "there is an overexploitation that would be related to the sinking" and that three public entities will present charges against the mining company.
“The Gaby 4 mansion was designed and authorized for an exploitation of 400 thousand tons and according to the data obtained in the investigation, it was detected that 300 thousand tons have been extracted and inside the mansion there are at least 300 thousand more tons. ”, said the minister this Thursday after meeting with local authorities and representatives of the Ministries of Housing, Public Works and the Environment.
"That clearly means that there is overexploitation that would be related to the sinking and that in turn could have affected the existing aquifer in the place," she added.
From the Ojos del Salado mining company they have assured that the sinkhole "does not generate risks for the population since it is 600 meters from the nearest house, while it is more than 800 meters from any other populated center or public service", according to Edwin Hidalgo, manager of External Communications and Public Affairs of the company.
The greatest concern of the authorities involved in the matter has to do with the aquifer that, "when it breaks due to mining activity" has caused "water to drain into the mine," said the minister.
The mayor of Tierra Amarilla, Cristóbal Zuñiga, pressed for the technicians to give forceful answers about the causes that originated the sinkhole "and how to explain that a new circle of cracks is appearing."
In three sectors near the hole they have detected cracks on the surface, which are being monitored by the Chilean National Service of Geology and Mining (Sernageomin) with a radar system, drones and extensometers.
This Friday they have started geophysical studies to confirm that the cracks are not increasing their dimensions.
Ojos del Salado has ruled out that in the sectors of the cracks there is an excavation or underground mining operations and there are no nearby towns.
Hidalgo, spokesman for the company, maintained that they were detected before the sinking occurred, "as part of study work in the area, and are part of an event independent of the sinkhole."
Sernageomin, the Superintendence of the Environment (SMA) and the General Directorate of Waters (DGA) will present legal actions against the Ojos del Salado mining company for the sinkhole.
For their part, deputies from the area are working on the creation of an investigative commission in the lower house.
In the middle of the month, the SMA ordered the mining company six urgent and transitory measures, including carrying out a soil stability study in the area of direct influence of the event, considering a radius of 500 to 800 meters, and the delivery of a technical study to verify whether the volumes of water historically extracted by the mining company have generated or not a detriment to the alluvial aquifer of the Copiapó River or another present in the area.
The company has 30 business days to execute orders issued on August 12.
subscribe here
to the newsletter of EL PAÍS América and receive all the key information on current affairs in the region.
