A study conducted by researchers at Universidade of Pequim revealed that the rotation of the inner core of Terra may have recently stopped. Scientists have analyzed seismic waves generated by earthquakes since the 1960s. The data indicates that the movement has slowed significantly in the last decade, approaching a relative pause in relation to the rest of the planet. Essa change is part of a recurring cycle that occurs approximately every seven decades.
The inner core consists of a solid sphere composed mainly of iron and nickel. Ele is located approximately 5,100 kilometers below the Earth’s surface. Separado of the mantle by the liquid outer core, the inner core rotates independently of the planet’s overall rotation. Sua dynamics result from the interaction between the magnetic field generated in the outer core and the gravitational effects exerted by the mantle.
How scientists detected the change in rotation
Researchers Yi Yang and Xiaodong Song examined variations in the seismic waves passing through the inner core. Essas waves change speed as they pass through different layers of the planet. As of 2009, records showed minimal variations over time. Essa stability suggests that the inner core has drastically reduced its rotational speed compared to the mantle and crust.
The analysis covered data collected over decades. Scientists observed that the nucleus rotated slightly faster than the rest of Terra in earlier periods. Agora, the synchronization has increased, which indicates a deceleration close to a relative stop.
Recurrent cycle observed in past decades
The phenomenon follows a cyclical pattern of approximately 70 years. A similar turn occurred in the early 1970s. Entre the 1980s and 1990s saw a clear change in rotational dynamics. Current data point to the beginning of a new cycle, possibly with a reversal of the direction of rotation.
Experts reinforce that the process occurs gradually. Não is an absolute stop, but greater alignment with the planet’s surface rotation. Essa oscillation is part of the natural behavior of the inner core.
Inner core structure and factors influencing movement
The inner core remains solid despite high temperatures due to extreme pressure. Ele measures about 2,400 kilometers in diameter. The liquid outer core generates the Earth’s magnetic field through the movement of molten metals. Esse field drives the differential rotation of the inner core.
Gravitational effects of the mantle act as a counterweight. Essa balance maintains the overall stability of the system. Alterações in rotation arise from complex interactions between these forces.
Implications for future geophysical studies
The discovery highlights the importance of seismic wave-based methods for monitoring the interior of Terra. Pesquisadores emphasize the need for additional data and innovative techniques. Esses advances allow us to better understand the deep dynamics of the planet.
Geophysicist Hrvoje Tkalcic of Universidade Nacional Australiana noted that the “stop” interpretation should be cautious. Ele indicates greater rotational synchrony, with no evidence of cataclysmic surface impacts. Continuous Estudos help refine models about the behavior of the nucleus.
Details about seismic wave monitoring
Scientists use earthquakes as natural sources of waves. Essas waves propagate across the planet and undergo changes as they cross the core. Registros of global seismographic stations provide accurate information about speeds and trajectories.
Comparing pairs of similar seismic events over time reveals subtle changes. Essa approach made it possible to identify the recent slowdown. Data accumulated since the 1960s strengthens the reliability of the conclusions.
Perspectives for understanding the magnetic field
The inner core indirectly influences the magnetic field generated in the outer core. Mudanças in differential rotation can affect convection processes in the metallic liquid. However, surface effects remain minimal and gradual.
Ongoing research seeks to correlate these variations with other geophysical phenomena. Continuing studies guarantees advances in knowledge of the Earth’s interior.