The program and tasks of the important oceanographic mission of the American research vessel “JOIDES Resolution”, which will carry out offshore drilling around Santorini from mid-December 2022 to mid-February 2023, were presented by foreign and Greek scientists in yesterday’s “hybrid”. (live and online) event of the Department of Geology and Geoecology of EKPA.

The purpose of the drilling is to reconstruct the geological history of the Christiania, Santorini and Columbo volcanic complex by collecting sediment cores through the sediments and volcanic layers of the seafloor. Expedition 398 IODP is part of the International Ocean Discovery Program (IODP).

Drilling is planned at six key locations (12 alternatives have been identified) at depths of 300 to 700 meters and 230 to 860 meters below the seabed. The ship starts from Spain, explores the volcanoes around Santorini and stops in Crete. On board will be 28 scientists from nine countries, as well as many technicians and engineers. Three women scientists will take part in the international oceanographic mission from the Greek side: Associate Professor Paraskevi Nomiko (Department of Geology and Geoenvironment of the Hellenic Academy of Sciences), Dr. Olga Kukusiura (Department of Geology of AUTH) and Researcher Paraskevi Polimenakou (ITHAVBIK Institute ELKETE).

According to Ms. Nomiku, “The structure of the active tectonic Christiana-Santorini-Columbo zone runs through the islands of Santorini-Amorgos with a length of more than 140 kilometers and includes the volcanic centers of Christiana, Santorini and Columbo, which are ideal natural laboratories for studying the interaction of volcanism and tectonics. These volcanoes are located within a 100 km sea basin where mud and volcanic materials have been accumulating for about four million years, providing a wealth of information about the history of these volcanoes. Recording past explosive eruptions provides information about their frequency, size, and intensity, as well as marine geology. It also includes a number of active faults that have generated major earthquakes, such as the 1956 maximum 7.5 Richter earthquake on Amorgos. The research team, having studied the geophysical data they had, chose suitable places for research drilling, and when the collected cores are analyzed, the volcanic danger of the area will be clear. New quest Exp. 398 will extend this quantitative information to the entire region of the Greek volcanic arc.

The importance of the mission, as well as Greece’s contribution to it in gathering more important data on the region’s volcanoes, was emphasized in their greetings by EKPA Chair of Geology Prof. Asimina Antonaraku, EKPA Distinguished Professor of Geology Dimitris Papanikolaou (retired of the pioneers of the mission for many years) and President Greek Geological Society Athanasios Ganas. Ms. Nomiku emphasized that during the mission there will be absolute transparency and timely reporting of the findings, as daily reports will be prepared for the Greek authorities and the public.

Leading professor of volcanology Tim Druitt from the French University of Clermont-Auvergne noted that there are more than 1,000 potential active volcanoes in the world and 800 million people live within a radius of 100 km from an active volcano. “That is why,” he said, “it is very important to understand what causes a volcanic eruption and what we can learn from their behavior in the past, as well as the potential threats of a possible eruption in the future.” As a typical example of a violent volcanic eruption, he cited the Tonga eruption last January, one of the most violent ever recorded, when a volcanic plume reached a height of 35 km in the atmosphere, and the recorded wave impulses seemed to make repeated cycles around the Earth. “Volcanologists have realized that there is still a lot we don’t understand about these types of eruptions,” he said.

Druitt noted that “Santorini is one of the most explosive volcanoes in the world. Each of the layers visible on the flanks of the caldera was formed during previous volcanic eruptions, some of which were particularly violent. The volcanic history of Santorini, recorded in its rock formations on land, has been carefully studied by scientists. However, this record is incomplete, and it is time to move on to maritime space, where the preservation of the volcanic record is likely to be much more complete. It will also allow us to interpret volcanic events up to millions of years ago. And let’s not forget this: the study of past volcanic activity gives us information about what we can expect from possible future activity.”

Of another nearby underwater volcano, Columbo, he said that it “definitely poses a big threat to Santorini in the future and we need to learn more about the history of its eruption.”

Two wells inside the caldera

The expedition will drill at two locations in the Santorini caldera. Druitt said that “drilling in the caldera will be carried out under special conditions so that biologists can take samples and characterize any microbes that live in rocks deep inside the caldera. We already know that there are colonies of microbes at the bottom of the caldera, and we will be able to study what happens to these life forms when they are buried by repeated volcanic eruptions up to 360 meters below the seabed.”

He also stressed that “Of course, we will publish our results, which will be available to scientists, the public and authorities. However, we will not deal with archaeological issues, we will not deal with works that have commercial applications, we will not look for hydrocarbons. There is no reason to be concerned if drilling could cause an explosion, since the magma under the caldera is much deeper than we are drilling. In addition, the well is very narrow, so it could not cause an earthquake. In addition, our plans have been carefully reviewed by IODP security experts who have extensive experience in these matters.”

According to Dr. Carol Cotterill of Columbia University’s Lamont-Doert Geoobservatory, who is responsible for information work at the IODP, the mission has enormous information potential, as Santorini is an iconic site for both volcanology and archeology, attracting millions of tourists every year. There will be two mission monitors: one aboard and one ashore. Promotions on social media, blogs and websites nationally and internationally will run continuously during the mission.

Dr. Steffen Kuteroff of Germany’s Helmholz GEOMAR Center for Oceanographic Research said the offshore research drilling vessel JOIDES Resolution, or “JR”, is 143 meters long and 21 meters wide, with its 62-meter-tall drilling crane being the vessel’s highest point. vessel. With his crane, JR can drill up to 2 km below the seabed in oceans up to 6 km deep. He and Thomas Ronge from Texas A&M University in the USA assured that all necessary measures will be taken to protect the environment when drilling in the Aegean. and marine life.

Exhibition

From 21 to 25 November (hours 09:00 – 17:00), the periodical exhibition “In Search of the Secrets of the Earth” is open at the Museum of Paleontology of the Department of Geology and Geoenvironment of the EKPA on the Zografou Campus. This is an educational interactive exhibition for all ages that shows how offshore exploratory drilling can be used to solve the Earth’s geological mysteries. The report, which was first presented in Santorini, will include information specifically about the expedition around the island this winter.

Source: RES-IPE