In Brief

The BedrettoLab (Bedretto Underground Laboratory for Geosciences and Geoenergies) is a unique research infrastructure run by ETH Zurich making it possible to take a close look at the Earth’s interior. It is located in the Swiss Alps 1.5 kilometres below the surface and in the middle of a 5.2 kilometres long tunnel connecting the Ticino with the Furka railway tunnel.

Equipped with the latest technology, the BedrettoLab offers ideal conditions to conduct experimental research focusing on the behaviour of the deep underground when accessing and stimulating it. Such an access is required to advance scientific knowledge in various domains including geothermal energy and earthquake physics. It is also of relevance to develop novel techniques and sensors for these purposes.

Learn more about the scope of the project.

ETH Zurich logo  Swiss Competence Center for Energy Reasearch Supply of Electricity logo Werner Siemens Foundation logo European Union Funding Horizon 2020 logo

News

BedrettoLab Open Days

Last weekend, more than 200 visitors came to Bedretto and toured the BedrettoLab.

On Friday, 2 June, collaborators of the Earth Science Department of ETH Zurich were invited to see what the BedrettoLab team has built over the last few years. In each of the five tours, three members of the BedrettoLab team guided around 20 visitors through the tunnel, 2.5 km to the BedrettoLab and back. This event was an excellent opportunity to not only show the infrastructure and provide insights into current research projects but also to foster the research network within the Earth Science Department community.

The next day, the BedrettoLab opened its doors to the public. Around 100 interested people signed up for the six guided tours to explore the BedrettoLab. With the long Covid related break that made public tours impossible, this event marked a milestone to present the lab to the public and show what has been set up since the inauguration of the BedrettoLab in 2019. 5 June 2023

Researching the geological evolution of the Rotondo massif

Alberto Ceccato is a structural geologist and investigates geological phenomena such as earthquakes and faults. With a variety of research methods, he is aiming to find out more about the geological processes and mechanisms that controlled the development of those faults through time. This knowledge helps other researchers of the BedrettoLab like geophysicists or engineering geologists to better understand the geological characteristics of the faults they are interfering with. Usually Alberto’s research journey starts with a field trip where he gets a very close look at the rocks. Last summer, he spent around one month in the Rotondo massif telling us now about his research adventure and his findings.

In June 2022, I started with field work for my research on the Rotondo massif. My aim was to find out more about the faults that we are dealing with in the BedrettoLab, about their age, their quantity and their main characteristics with regards to their mineralogy, length, and orientation. The typical tools of a structural geologist during its fieldwork are a compass, a notebook, a tablet, a hand lens and a camera. As I entered quite difficult terrain, I also always had a GPS-tracker with me.

Field observations

On the notebook, I wrote down any interesting detail that I observed regarding the geological characteristics of the Rotondo massif: the contents of minerals of the rocks, their size and distribution in space, the distributions of the structures and fractures in the massif, etc. The structures that I am most interested in are faults. For a structural geologist, a fault is not just a plain of two rock volumes touching each other. It is a large volume of rock that had been crushed and transformed by strong mechanical forces, sometimes associated with earthquakes, and developed in geological ages which means several millions of years. The final result of these processes, what we actually see in the field, is the formation of fault rocks, so called gouges and cataclasites: fine grained rocks made of quartz, micas, and clay minerals born from past earthquakes and rock deformations along faults. Most of the time, these fine-grained rocks are eroded easily, and they usually form valleys and gullies into which water infiltrates. However, hiking around the Rotondo massif I have found several well-preserved outcrops where it is still possible to see and study in detail such faults and fault rocks.  

On the tablet that I also carried with me, I used a dedicated GIS (geographic information system) software where I mapped the faults that I could recognize on the field. By adding my observational data into a digital map, I got an overview of the whole area and how the different faults are distributed. Additionally, precise drone pictures from the area helped to get detailed images of the area that I am looking at which is around 8 km2 large. Altogether, the data collected from my field work consists of hand notes, digital mappings, photos, drone images and lastly rock samples.

Looking back 295 million years

After about 30 days spending in the mountains, I returned to my office at ETH Zurich to start with analytical work on my computer and in our laboratory. With a certain grinding method, our laboratory technician created a very thin layer of rock that makes it possible to be analysed under the microscope. This allowed me to learn more about the micro-structure and geochemical composition which are indicators for the geological process generating the fault rocks at the age of the fault. With the combination of the large-scale methods in the field and the microscopic scale research methods, I was able to draw the story of the Rotondo massif back from the origins up until today.

It is quite long and troubled, starting at around 295 millions of years ago, when the Rotondo granite solidified from hot magmas deep in the Earth’s crust. Plate tectonic forces acting during the formation of the Alps squeezed and crashed the Rotondo granite, leading to the development of a sequence of different sets of faults and fractures. Each of these sets is characterized by different minerals, chemical compositions and fault orientations, suggesting that each set formed at different depth and temperature conditions through the geological history. Some of these faults and fractures likely generated during earthquakes, and thus further analysed will help us to understand the geological characteristics which might control earthquake generation in the Rotondo granite. 26 April 2023

This text was published in the latest issue of the "Gazzettino di Bedretto" (in Italian).

Virtual Tour

Click on play and get a deep insight into the BedrettoLab.

Newsletter

News and interesting facts from the Bedretto lab fresh in your inbox! Sign up for the newsletter here: