Earth’s Inner Core is Undergoing Structural Changes

Syllabus :GS 1/Geography

In News  

• A recent study published in Nature Geoscience suggests that the Earth’s inner core is undergoing structural changes.

About the Study

• Methodology: Researchers used seismic waves (shockwaves from earthquakes) to examine Earth’s internal layers.
  • These waves help visualize the Earth’s internal structure, similar to how CT scans work for the human body.
• Observations Made:  
  • Scientists previously assumed Earth’s inner core was solid and rigid. New findings suggest it is softer near the surface.
  • The solid inner core is being influenced by the turbulent molten outer core. This interaction might be altering its rotation and affecting Earth’s day-length.
  • Earlier, it was believed that the inner core rotates independently due to interactions with the mantle. The study suggests that this rotation is now slowing down.

About Earth’s Layers

• Earth is a dynamic planet that undergoes continuous changes inside and outside.
• The Earth is made up of several concentric layers:
  • Crust: The outermost layer; thinnest (35 km on continents, 5 km on ocean floors).  It consists of silica and alumina (sial) on continents and silica and magnesium (sima) on the ocean floors.
  • The Mantle: Located beneath the crust, extends from the Moho’s discontinuity to a depth of 2,900 km.
    • The upper portion is called the asthenosphere (extends up to 400 km) and is the main source of magma.
    • The crust and the upper mantle form the lithosphere with a thickness ranging from 10-200 km.
    • The lower mantle is solid and extends beyond the asthenosphere.

• The Core: Located beneath the mantle at a depth of 2,900 km.
  • The core has very high temperature and pressure and It consists of two parts:
    • Outer core: Liquid state.
    • Inner core: Solid state.
    • Made mostly of nickel and iron, sometimes called the nife layer.
  • The outer core has been known to be turbulent, it was previously believed that this turbulence did not affect the inner core on human timescales.

Source :DTE