Research line

Marine Geophysics

Eduardo Contreras R., academic of the Department of Geophysics of the University of Chile, leads this line of work in the INSUD and in the following paragraphs he explains the work that will be carried out.

“We will focus on the study of the structure and characteristics of the Nazca Ocean Plate and the offshore region of the South American continental plate. The process of subduction begins at the ocean floor, that is, when the oceanic plate begins to subduct or touch below the continental plate. We seek to understand the importance of the Nazca Plate and the part that makes contact with the continental plate that is under the sea», commented the DGF professor and researcher of INSUD.

““Subduction processes begin at the ocean floor. If we do not understand the beginning of subduction, we can hardly understand the subduction process globally.”

What is the relevance of this line?

The academic Eduardo Contreras argued that «the subduction processes begin in the ocean floor; thus also with respect to the largest earthquakes that have occurred in Chile, its rupture area is almost 80% under the sea. So, if you do not understand the beginning of subduction, you will hardly understand the process of complete subduction and that is where the importance of studying this line lies»

What crossings stand out with the other lines of research?

The professor of the DGF stressed regarding the line of volcanism that «the oceanic plate of Nazca is the one that brings stored water that later is expelled to depths of 100-150 km due to the high conditions of pressure and temperature and that affects the fusion partial causing magmagtism and thus promoting volcanic activity in the Andes. In this way, if you do not understand what the structure of the oceanic plate is, you will not understand the volcanic processes globally in the process of subduction. «

Regarding the line of seismology, he stressed that for the modeling of tsunamis, one of the main inputs needed is related to the knowledge of the topography of the seabed. «Marine geophysics provides key information to carry out tsunami modeling,» Contreras concluded.

What will be the study areas?

Like the rest of the lines, the work will be mainly carried out in two large areas of the country: the large north and in the south in the Los Lagos region.

However, the DGF academic stressed that «if during the three years of the project an earthquake or a major volcanic eruption occurs in another place in Chile, including certain areas of Peru (since geology has no borders) it will be incorporated in our study. «

“Understanding the natural environment of a country located in a subduction zone is crucial to reduce the impact of natural hazards”

Eduardo Contreras, principal research of Marine Geophysics line

Marine data collection

The INSUD researcher commented that due to the high costs of marine subsoil investigations, since they are complex, expensive and must be carried out on board a scientific research vessel, work will firstly focus on the analysis and study of data that were previously collected.

«Data that we have already acquired will be used, and we will continue our applications to get on board Cabo de Hornos research vessel, and thus be able to collect more marine records,» said Contreras. In early 2018, the INSUD researcher, Andrei Maksymowicz embarked on this ship of the Chilean Navy, together with students of the Department of Geophysics, with the purpose of collecting data in the area near the earthquake that occurred in Illapel during 2015. On the occasion they were the only scientific group on board the ship that performed marine geophysics. His research focused on two areas: performing high resolution bathymetry and using the marine sub-bottom profiler of the ship, to analyze the structures of the Nazca Oceanic Plate, located immediately west of the subduction under the continent.

Another field work carried out at the end of 2014, including a team led by Professor Contreras and researchers from the University of Kiel and GEOMAR Institute (Germany), installed a submarine seismometer network that focused on monitoring the seismic activity in the rupture zone of the Iquique earthquake (April 2014). The cruise lasted approximately one week aboard the OPV  Toro from the Chilean Navy that, together with SHOA, participated in this scientific project.

Regarding the data collected in north and south Chile, Eduardo Contreras reported a collaboration project, during 2016 and 2017, between researchers from the Research Institute of the University of Texas at Austin, the Oregon State University of the United States and the DGF – University of Chile, aboard the American R / V  Marcus Langseth of the University of Columbia. During this expedition, images of the seabed and marine subsoil were obtained, to better understand the surface and internal structure of the Nazca Plate. The expedition lasted approximately 40 days and three areas of central and south Chile were studied, where the ruptures of the Illapel earthquakes in 2015, the Maule in 2010 and the Valdivia in 1960 were generated.

How will this research line point to the formation of human resource?

Eduardo Contreras pointed that, like other work lines, postgraduate students – master and doctorate – associated with the project will be incorporated