Active volcanoes of the Central Andes: An Argentinian perspective

BERTIN D; ELISSONDO M; PABLO CAFFE; WALTER BAEZ; LINDSAY J

Congreso; XV Congreso Geológico Chileno; 2018

Compared to its Chilean counterpart, the ArgentinianCentral Volcanic Zone (CVZ) of the Andes has not held the same attention interms of active volcanism and volcanic hazards. Indeed, although that the mostrecent global volcanic database mentions 30 Quaternary volcanoes, 19 of themactive (Siebert et al., 2010), localdatabases list up to 250 Neogene and Quaternary volcanic centers, 36 of themvery youthful-looking (e.g. de Silva and Francis, 1991). These studies weretaken into account by Elissondo and Villegas (2011) for addressing thequestions: 1) How many volcanoes are in the Argentinian CVZ?, 2) How many ofthem are active?, and 3) How deep do we know them?. Thus, they defined 20active volcanoes following the activity criteria of Ewert et al. (2005), yet none of them were included into the preliminarymonitoring project led by the newly government-funded Argentine Observatory ofVolcanic Surveillance (OAVV; García etal., 2017, and references therein).The Argentinian CVZ covers an area of about 60,000 km2,spanning the Jujuy, Salta, Catamarca and La Rioja provinces, in the mostnorthwestern extreme of Argentina, towards its international border with Chile.It includes scoria cones, lava fields, domes, lava-domes, tuff rings, tuffcones, maars, calderas, and small-to-medium sized stratovolcanoes,compositionally ranging from basalts to rhyolites. In spite of the extensivegeochemical (e.g. Maro et al., 2017),structural (e.g. Zhou et al., 2013)and geophysical (e.g. Mulcahy et al.,2014) research done in this zone since the 1980s, there are scarce stratigraphical,morphometrical, geomorphological and geochronological studies. Furthermore,volcanic hazards have only been assessed from a quite broad perspective(Perucca and Moreiras, 2009; Elissondo etal., 2016, 2017).The overall poor state of the hazards? knowledge ofthese volcanoes has led to a planning focused on a better understanding of thistopic, conducted by colleagues from the Jujuy, Salta, and Tucumán universities,in collaboration with Mexican, Italian, and Spanish researchers (e.g. Norini et al., 2014; Báez et al., 2016; Grosse et al.,2018). On a wider perspective, a regional-scale volcanic hazards assessment iscurrently being carried out by people from the University of Auckland (NewZealand), together with researchers from the University of Jujuy, theUniversity of Salta, and scientists from the Argentinian Geological and MiningSurvey. Despite that this project is still in its first year, their preliminaryresults suggest that volcanic phenomena in the region are comparable both interms of magnitude and coverage, and possibly recurrence, with those of theChilean CVZ. That is to say, we hypothesize that the volcanic hazards in theArgentinian CVZ have been overlooked so far.