Site testing in the Northwest of Argentina

P. RECABARREN, D. GARCÍA LAMBAS, H. MURIEL, F.STASYSZYN, V. RENZI, R. VRECH, J. VIRAMONTE AND M. SARAZIN

Hawai

Simposio; Symposium on Seeing; 2007

National Science Foundation

We present different results of the characterization of the Tolar Grande - Macon Range site in the North-West of Argentina. This project is being developed by the IATE Group of Córdoba Observatory in collaboration with ESO in the framework of the E-ELT project. We present and discuss one year of image quality measurements with MASS and DIMM, three years of meteorological data and detailed studies of seismic activity and geo-technical aspects as well as diverse logistic issues.Geographic descriptionThe NW of Argentina between, 23º 15´ and 24º 30´ South latitude and 65º 30´ and 67º30´ West longitude, Known as Puna region, is a high plateau ranging between 3000 and 4000 m. There are several mountain ranges with peaks reaching more than 6000 m.General facilities of the areaSalta is the main city, comparable or larger than the Chilean Calama and Antofagasta.Salta provides facilities and infrastructure such as airports, universities, communications, electric power stations, hotels, car and truck rentals, shopping centers, etc.San Antonio de los Cobres: is the main town of our interest area (3781 m.a.s.l., 3200 inhabitants) through a 120 km paved road from Salta.Tolar Grande: Small town of 175 inhabitants (3550 m.a.s.l) close to the site: MacónRange 320 km away from Salta (200 from San Antonio de los Cobres through a nonpaved road in good conditions. A railway track from Salta City to Antofagasta (Chile)through San Antonio de los Cobres, Tolar Grande and Socompa pass.The Candidate Site (Macón Range)Four candidate locations were preliminary selected after GOES satellite images, NIMBUS data analysis, analysis of tectonic and geographical issues as well as severalexploration trips to the area. Macón Range: Toward the East of Arizaro Salt Flat, thereis the Macon Range, at 5450 m.a.s.l. extends from the southeast of Mount Rincon, in the Chilean border to the South East of Tolar Grande Town, at the East of the middle of Arizaro salt flat. Macon Range runs in north to south direction and there are no comparable altitudes to the west near 50 km.Macón range has several features that make it suitable for large observational developments. The combined facts of wind regularly from the WNW and E directions,the North- South layout of the Macon range and the presence of the large Arizaro SaltFlat at the West of Macón and Pocitos Salt flat at the East, provides particularconfiguration that strongly suggest a laminar wind regime on the top of the ridge.Tolar Grande (which offers several facilities) is located between the Macon Range and the Arizaro Salt Flat.