Context: Recent geological studies have revealed that the northern region of Iraq, particularly around the Zagros Mountains, is experiencing slow but geological changes. A research team has identified a sinking oceanic slab beneath the Earth’s surface that is gradually pulling this area downwards. This phenomenon is a result of complex tectonic processes occurring over millions of years.

Key-findings of the Study

• Neotethys Oceanic Plate Rupture: The study reveals that the Neotethys oceanic plate (once the seafloor between the Arabian and Eurasian continents) is slowly breaking off horizontally. This rupture is extending from southeast Turkey to northwest Iran.

• The sinking of this oceanic plate (part of plate tectonics) beneath the Earth's surface contributes significantly to the bending and subsiding of the region’s surface.

Surface Depression and Sediment Accumulation:

• Over millions of years, the immense weight of the Zagros Mountains has caused the Earth's surface around the mountains to bend downward. Sediments eroded from the mountains accumulated in the depression, forming plains like Mesopotamia in the Middle East.

• Depression of 3-4 km deep is observed, which could not be solely explained by the weight of the mountains. Instead, the sinking oceanic plate beneath the region is playing a key role in pulling the surface downward, making space for more sediment to accumulate.

Why is it Sinking?

• The sinking is caused by a tectonic process. The Earth’s surface is made up of large plates, and these plates are constantly moving.

• Tectonic Plates: The plates that make up the Earth's surface are constantly moving, and where they meet, they can cause changes to the land above.

• Neotethys Slab: Below the Zagros Mountains, there is a piece of ocean floor called the Neotethys slab. This slab is slowly sinking into the Earth’s mantle (the layer below the crust). This process started millions of years ago when the oceanic plate broke off, and it's still happening today.

• Plate Collision: The sinking is happening because the Arabian Plate and the Eurasian Plate are colliding. This collision has created the Zagros Mountains, and the sinking slab is pulling the land down with it.

Implications for Earthquake Prediction

• The findings have significant implications for earthquake prediction by enhancing the understanding of the planet’s interior dynamics. The study helps develop more accurate geological models depicting deep-earth activity.

• Earthquakes result from the displacement of rock layers along faults, which can occur at various depths and scales. Understanding the geological configuration and rock geometry enables scientists to predict the location, depth, and magnitude of potential earthquakes.

Relevance to Energy and Regional Safety

• The study is particularly relevant to the region, given its vulnerability to seismic activity. In February 2023, massive earthquakes in southern and central Turkey and northern Syria resulted in tens of thousands of deaths and widespread destruction.

• Additionally, understanding the region’s topography and historical changes helps identify depths with high geothermal gradients, crucial for sustainable electricity production.

About Plate Tectonics

• Plate Tectonics: The movement of tectonic plates causes the collision of continents and oceanic plates. The collision of the Arabian Plate with the Eurasian Plate resulted in the formation of mountain ranges like the Zagros.

• Oceanic plates are typically denser than continental plates and tend to sink beneath them when plates collide. The Neotethys oceanic plate is an example of this sinking process.

• Orogeny (Mountain Building): The Zagros Mountains were formed through a process known as orogeny, where tectonic plate collisions lead to the uplift of large rock masses, creating mountains over millions of years.

Zagros Mountains (Kurdistan Region, Iraq)

• The Zagros Mountains stretch across southwestern Iran, extending from the border regions of eastern Turkey and northern Iraq to the Strait of Hormuz.

• The range is approximately 1,600 km long and 240 km wide.

• Geological Composition: The oldest rocks in the range date back to the Precambrian period (over 541 million years ago). Most rocks are limestone and shale, with formations from the Mesozoic Era (252 million to 66 million years ago) and the Paleogene Period (66 million to 23 million years ago).

• Formation and Tectonic Activity: The range was formed through orogenies (mountain-building events) caused by the Arabian Plate moving beneath the Eurasian Plate during the Miocene and Pliocene epochs (23 to 2.6 million years ago).

• Highest Peak: The highest point is Mount Dena, which reaches an elevation of 4,409 meters (14,465 feet).

Mesopotamia (Middle East)

• Mesopotamia, located between the Tigris and Euphrates rivers, is a historic and fertile plain that has accumulated sediments from the erosion of the Zagros Mountains over millions of years.

• The depression caused by the weight of the Zagros Mountains has influenced the topography of this region, which has historical significance for civilization.