LIGHT POLLUTION

Even though the second and third regions of Chile are located in what is one of the most inhospitable places in the world, its enourmous wealth in minerals has attracted mining companies over the years to exploit it and this has also made it necessary to create cities that will support the mining activity. The coastal cities are mainly used to export the minerals whereas the inner cities are directly suporting the mines. Some of the mines put out as much light as some of the major cities all by themselves and therefore are just as much a threat to an observatory as the cities. The cities have room for growth espeacially if the mining activity picks up, which it certainly seems to be doing.

CTIO Light Pollution page
Study of light pollution growth

Population growth in the North of Chile

The following table shows the growth of the cities in the second, third and fourth regions over the last ten years as well as a projection of their growth until 2005, the information used to generate this table and its corresponding graph was provided by INE, the chilean institute for statistics. The table is divided into three sections which correspond to the three regions of interest (II,III,IV Regions respectively).

The following image shows the above information in a graph.

Mining and City Centers in the North of Chile and its effect on light pollution

"Over a dozen mining projects will be developed in Chile during the first two years of the new millennium.  The mining community expects that in the near future metal prices will be considerably better than the ones registered in the last couple of years. The improved prices will enable investors to persevere with the new investments planned to be made in Chile.  The estimated amount of investment in new projects is upwards of US$9 billion.

During 1998 copper price averaged US$0.75 cents per pound, 25 percent lower that the price registered in 1997.  Exports for 1998 were US$5,4 billion, while in 1997 it amounted to US$7,1 billion.  During the first semester of 1999 total exports totaled US$6,7 billion, but this figure was due mainly to the volume exported rather than to better prices.  This result in volume was due to several positive factors such as the beginning of operations at Dona Ines de Collahuasi and the increased production of the mines Radomiro Tomic (CODELCO), La Escondida and Cerro Colorado.  All of these mines are located in the Second Region of Chile."  www.mining-journal.com

Mining activity in the North seems to be getting larger every year, with most mines making heavy investment to double their production, this means that mines will be getting bigger and brighter. The selection of possible sites mainly avoided areas within 50km line of sight of any major mine.


Major Mines and Cities in the North of Chile (luminescence)


 

Escondida mine

The Escondida Mine is owned and operated by Minera Escondida Limitada which has as its main shareholders BHP-Mining and RTZ. High grade copper ore is mined at 65,000 tons per day from an open pit, milled and floated to produce a copper concentrate. The mine was expanded in 1995 to increase production to 115,000 tons per day. At the start of its present phase IV expansion plan it was producing 127000 tons of copper a year, at the end of the expansion it will be producing 175000 tons a year. It is located at an elevation of 3,000 m in the Andes, 150 km southeast of Antofagasta. Water is a scarce commodity in this high desert area and recovered from a wellfield of limited capacity 45 km from the mine. Tailings disposal was initially discharged into a "salor" (closed drainage area) without need for embankments or containment structures. This ultimate tailings deposit, which will be the largest in the world (3 billion tons),is encroaching on the ultimate pit limits.
 
 

El Abra mine

Phelps Dodge and CODELCO are the main partners on the El Abra mining project, at present it is producing about 225000 tons per year of copper.The El Abra mine is located about 80km North of Chuquicamata in the second region  at an elevation of 4000 meters, Comercial operations at the El abra site began in 1996. A state-of-the-art conveyor system at El Abra transports 10000 tons per hour of crushed oxide ore from the mine to the processing plant, a distance of more than 14 kilometers. (above picture)
 
 

Collahuasi Copper Mine

The Collahuasi porphyry copper deposit commenced operation in 1998, with a projected annual production rate of 380000 tons of Copper. It is located in the first region.  The operation is a joint venture between Falconbridge and Minorco, with minority Japanese partners. The Collahuasi mine is a large scale mine with reserves of 3.1 billion tons, 2 billion tons of which is accessible. It is has been the mine with the largest single investment in Chilean history of aproximately 1.8 billion dollars and has a lifespan of 25 years at present production.

Remarks

Even though the world copper prices have been going down over the past few years, there have been major investments in chilean mining in the 1st and 2nd regions.The main mining activity is centered around Calama, with Chuquicamata and El Abra, to the North in the Cordillera with Dona Ines de Collahuasi and at Escondida. These mines limit the places a potencial site could be located, Escondida and Chuquicamata are quite inconviently placed as there are a few good sites within 50 to 100 km of these mines. Cerro Quimal for instance is located in an isolated place in the Atacama Desert, it has no mountain obstructions, but has however a direct line of sight of Calama and the Chuquicamata mine. Further investigation would be required of the light output of the mines to determine if they really make observing difficult on the proposed sites and on other potencially good sites such as Quimal.