The Eastern Mediterranean is 100 million years younger than what we thought and is “only” 150 million years old, according to a new study (Age and structure of the Levant basin, Eastern Mediterranean) published in the prestigious Earth-Science Review by Dr. Amit Segev of the Geological Survey, Prof. Eytan Sass of the Hebrew University and Dr. Uri Schattner of the Leon Charney School of Marine Sciences at the University of Haifa.
The study was presented two weeks ago at a meeting of the British Geological Society, which focused on the Mediterranean gas deposits, and included representatives of major energy companies. The age of the Mediterranean is an important component of gas and oil exploration models, and therefore the claim that it is 100 million years younger changes the basic assumptions held by experts in the field.
The fundamental article about the age of the Mediterranean was written 20 years ago, and, based on data available at the time, that study found that the area was created about 250 million years ago. The discovery of the gas reservoirs a decade ago has led to a burst of drilling in the eastern Mediterranean basin, with each drilling being accompanied with new data.
So when Dr. Segev, Prof. Sass and Dr. Schattner began their research, they had hundreds of new data items relating to the sediments, level of magnetism, material density and geological structure of the subsoil – in the coastal shelf and the deep sea. Their analysis of the new and old data together revealed that the Mediterranean was created “only” 150 million years ago.
The researchers explained that at this stage it is impossible to know whether their new finding increases or decreases the chances of finding additional energy reserves, but it is clear that they completely change all the basic assumptions that energy companies are working with today.
For example, the younger the Mediterranean, the less time natural gas has had to escape from the reservoirs, and the greater the chance that there is more gas. On the other hand, the researchers’ new age places its formation closer to the time of huge volcanic eruptions in the region some 150 million years ago, and so it seems that the subterranean reservoir areas were greatly warmed at the time. Warming would have encouraged the gas to escape from the reservoirs, so the chance of finding large reservoirs decreases.
Above all, the findings are very important in order to calculate the chances of discovering oil reserves in deeper layers, seeing as oil is a more desirable commodity than gas.
As part of the new study, the researchers made another discovery, which is more political in nature. According to United Nations Convention on the Law of the Sea (UNCLOS), which defines the rights and responsibilities of nations with respect to the management of marine natural resources, the 12 miles adjacent to the coast are considered part of the territory of each state, while the next 200 miles are considered the exclusive economic area of the same state, making every discovery of an energy reservoir within that area its property.
Because the Mediterranean basin is so small and crowded, no country owns a very large portion, and the sea is carved into slices belonging to each country. UNCLOS states that all the above measurements begin at the transition zone between the terrestrial crust and the sea crust – a coastal strip that until now has been shown to stretch only a few dozen kilometers from shore.
The new study found that for the State of Israel, this crossing strip is located hundreds of kilometers offshore, between Egypt and Cyprus. This could have a positive impact on Israel’s ability to exploit its offshore resources.