Volcanic Processes in the Chilean Andes
Daniel Díaz, academic from the Department of Geophysics of the University of Chile leads this line of work in the INSUD and in the following paragraphs explains the work that will be carried out:
Our focus on this line is volcanic eruptions as natural disasters. All the phenomena that occur between subduction and the surface crust are triggered by different reasons – such as dehydration or phase changes, for example – So, what we are looking for is to understand what happens at intermediate and large depths, what is impossible to analyze if it is not with indirect methodologies, since you can not draw a sample and study it. Therefore, from geophysics and with different methodologies it will be possible to have a notion of what is happening and the consequences that this has on the surface and in the generation of natural disasters, commented the INSUD researcher, Daniel Díaz.
What is the relevance of this line?
The research work in this area of the Anillo project is different from what has been done to date in the Department of Geophysics. Professor Díaz explained that during this time there has been a more brief study of what is under the volcanoes, but the work that will be developed from the INSUD points to the identification of structures of the order of 50 to 100 km deep that are related to subduction and that trigger volcanic systems.
«We will focus on the dehydration processes of the Nazca plate upon entering subduction and what that generates from the base of the continental crust towards the surface, leading to the production of volcanic systems. We will complement this with measurements that point to lower depths. «
Will you work with new equipment?
«We are going to buy three long-period magnetotelluric equipment, that is not available in Chile. These instruments serve to reach depths of the order of 100 km. It is expected that we will have them available in the country during the months of October-November of this year. Other geophysical equipment is also being acquired to carry out complementary studies and, in addition, the instruments will be provided by international institutions linked to the INSUD network.
Will the birth of a volcano or eruptions over time be studied?
Both processes will be studied. Here in Chile many volcanic arcs have been originated by systems of subduction different from those that we can observe at present. What we have now is product -or what we have had in recent years is product- of a subduction of a certain type that releases fluids and interacts in a certain way with the cortex; and that comes to the surface in a certain way and that may be changing.
«It is necessary to understand that volcanic systems are generated and live for a while and then change, but they are all long-term processes and we will see a kind of photo of the moment, which will help us understand not only what is happening now but also how this system should evolve forward «commented the DGF academic.
In which areas of Chile will work?
«In the north we will work at the height of San Pedro de Atacama, near the Lascar volcano and close to the El Tatio area. Here we will be working during the first year of work of the INSUD «
The second year of work will focus on the south of the country at the height of the volcanoes Osorno, Puyehue and Cordon del Caulle, in a specific area yet to be defined.
«During this time we have been studying in a more superficial way what is under the volcanoes, but the work that will be developed from the INSUD points to the identification of structures of the order of 50 to 100 km of depth that are related to the subduction and that unleash volcanic systems.»
Daniel Díaz, principal investigator of the Volcanic Processes line in the Chilean Andes
How do you dialogue with the other lines?
«We have the common objective that is to focus on the phenomena that are linked to subduction and that generate natural disasters in Chile. That is, from all the lines we want to see what subduction produces in the continental crust and that leads to triggering different events «Diaz added that the understanding of the disasters associated with subduction is in a constant dialogue between all the lines.
The faults are one of the zones or points of dialogue between the lines of the INSUD, since there is a direct relationship between fault systems and volcanism. One of the points highlighted by Professor Díaz is the mapping and identification of geological faults present to a large extent in the north of the country that is working in conjunction with the Marine Geophysics line. This part of the work is being carried out by Andrei Maksymowicz, a researcher associated with the Ring.
«There are many covered faults and systems that are not very well known and we will see how we can identify these systems and link them to the occurrence of volcanism in certain areas. There are many volcanic systems throughout Chile that seem to be «commanded» by faults, which can facilitate the ascent of fluids to the surface, due to the characteristics of faults «.
Human Capital Formation
In this line, as in the others of INSUD, we will be working on the training of postgraduate students. To date, the volcanology line has an associated Magister’s thesis student who develops his research in the north of Chile (Felipe Reyes).