A study by two researchers from the University of Alberta has revealed a hidden force deep within the Earth that may affect the speed of the planet's rotation, leading to a slight change in the length of the day by fractions of a thousandth of a second.
Hot Topics
About half of Libyans drink contaminated water What is the scientific reason?
Mauritania's blue treasure is in danger Will the map of fish in the Atlantic be redrawn?
The Citrus Secret Everyone's Talking About: Burn More, Crave Less & Feel Great Naturally
Physicists Huifeng Zhang and Matthew Demberi analyzed records dating from 1964 to 2019, combining seismic data used to track the rotation of the inner core with models of the movement of the liquid outer core reconstructed based on changes in Earth's magnetic field.
After excluding the effects of other factors that may affect the Earth's rotation, such as wind, ocean movement, and the long-term influence of the moon, the researchers compared the remaining changes in day length with the effects of three different mechanisms.
The results showed that the gravitational interaction between the Earth's inner core and the surrounding mantle represents the most consistent explanation for the observed changes.
The inner core is a very hot and dense sphere, composed primarily of iron and nickel, but it is not perfectly spherical. The mass distribution in the mantle is also uneven. As the inner core rotates, the interaction between these uneven distributions produces what is known as gravitational torque. This torque can slightly speed up or slow down the Earth's rotation, thus altering the time it takes for the Earth to complete one rotation on its axis and consequently affecting the length of a day.
The researchers linked this effect to a pattern of changes in Earth's rotation that spans approximately 70 years. They also found that the inner core, although solid, can slowly change shape in response to surrounding forces.
Calculations showed that the assumption of a completely solid inner core did not align well with the observed changes, while the results became more consistent with the data when the model allowed for gradual shape changes. The best estimates suggest these changes occur over a period of 8 to 10 years, while the possible range extends from 2 to 31 years.
The study also provided indications of a possible iron-rich, electrically conductive layer, approximately two kilometers thick, near the base of the mantle, along with clusters of hotter materials with a different chemical composition than the surrounding material. The researchers did not directly observe these materials but inferred their existence through models and calculations.
Despite the importance of the findings, researchers caution against considering the 70-year pattern as a regular and certain cycle, as it is still unknown whether this pattern repeats itself over time or reflects the conditions that prevailed during the seven decades covered by the data.
The results also depend on the models used to describe the movement of the inner and outer liquid cores, and some estimates have changed by up to 30% when different models are used. The study does not explain all variations in day length, particularly changes occurring over periods of 10 to 30 years, which may be more closely related to forces acting at the core-mantle boundary.
Nevertheless, the study offers a new way to understand what is happening deep inside the Earth, and shows how minute changes in the length of the day can reveal information about the movement, composition, and behavior of materials in the planet's interior.
what is your opinion on this news ?do let us know in the comments on tha comment box
if you liked this news article please share on friends & family & don't forget to follow on website & social media