Scientists have discovered that the residues of microorganisms that have long been extinct in the ocean can affect earthquakes/photos: David McNew/Getty Images
New Zealand Scientists have discovered that small dead organisms buried on the seabed can affect earthquakes and tsunamis. A study by scientists found that calcite sediments left by extinct organisms can affect the movement of tectonic plates.
Hikuranyi subduction zone is the largest fault near New Zealand and can cause strong earthquakes with magnitude of at 8 points or higher. Researchers studying the region found that calcite sediments left by large quantities of single-cell marine organisms tens of millions of years ago could control the levels of movement and friction between the Pacific and Australia's tectonic plates.
researchers explained that the key to this phenomenon lies in whether this calcite can dissolve. If it dissolves, the tectonic plates can slide against each other more easily. If this does not happen, it will block the movement of the plates, preventing the energy released later in the sudden explosion. Caroline Bolton, a structural geologist at Teherunga Waka of the University of Wellington, New Zealand, pointed out that
calcite dissolves faster when it is heavier in loads and lower temperatures. It dissolves more easily at low temperatures, such as at room temperature. But as the temperature rises, it becomes more difficult to dissolve, for example, deeper in the earth... Imagine these tiny, long-dead creatures can affect the mechanical interactions of two huge tectonic plates.
In the subduction zone, the temperature gradually increases with the depth, and the temperature rises by about 10ºC per kilometer. Calcite shells that are insoluble in depths of the surface can have a significant impact on fault movement. The
fault itself is difficult to reach and requires expensive drilling equipment to enter it, so the researchers used the open layers of limestone , amylin and mica on the local coast for their study. The rocks there contain calcite of marine organisms, mainly belonging to a type called foraminiferous (particularly plankton). The next question is how much of this calcite is located in the subduction zone and what state it is in.
According to Carolyn Boulton, the number and behavior of calcite from these organisms is an important part of the problem of how big a next earthquake may be.
Geologists know less about the Hikurange subduction zone than other faults in New Zealand because it cannot be studied at close range. The previous records of earthquakes were not so detailed, and the understanding of earthquake conditions was not so thorough, making it difficult to predict the next strong earthquake.
Researchers say that over the next 50 years, the likelihood of a strong earthquake along this fault is 26%, which could lead to a large tsunami.
Earlier, we reported that scientists discovered DNA fragments from 1 million years ago in the Scosha Sea, located in northern Antarctica, which could be invaluable to describe the history of the region - determining what lives in the ocean and at what time.
