Hi all. In this post I want to introduce myself and explain what I am doing the whole day.
I am Martin and I am a PhD-student at the University of Potsdam, Germany. My Project is part of the StRATEGy graduate school with 12 different PhD-projects from a geoscientific background focusing on NW Argentina. My part is the Seismology of the area.
You remember these old Western movies or the Lucky Luke comics were someone is trying to hear the arriving train while putting their ear on the railroad track? That’s a quite similar to Seismology, but instead of the ear we use seismographs and instead of tracks we listening to the earth.
Our plan for the following months is to install a network of 12-13 seismographs in northwestern Argentina in the area between Salta and Tucumán. The reason for our curiosity you can see in the map above. As we all know, in South America the Nazca-plate is subducting under the South American plate and forming the Andes mountains. Due to that mechanism we can observe volcanoes (red triangles) and a lot of earthquakes (colored circles). Along the subducting Nazca-plate you can observe earthquake only in specific depths (Wadati-Benioff-Zone); the further you go east from the pacific ocean, the deeper the earthquakes will be. In the map above the increasing depth is illustrated by the color change blue – greenish – yellowish – orange to red/white. But, in the frontal part of the orogene were the mountains end in the topographic map we observe very shallow earthquakes between 10 – 20km. And these very shallow earthquakes in the broken foreland (as the geologists call it) are the main interest of my work and study.
You can clearly see that there are much more and stronger (the bigger the circle, the bigger the magnitude) deep earthquakes than shallow earthquake. But the people living in this area are only interested in the shallow ones because they can feel these ones. And these events can also create damage like the event from October 2015 when an earthquake destroyed a school building in El Galpón.