The Earth’s crust and mantle beneath the oceans, known as the oceanic lithosphere, behaves in a mysterious way. It seems to move over a weaker region called the asthenosphere, which has different physical properties. This boundary between the lithosphere and asthenosphere is called the lithosphere-asthenosphere boundary (LAB). Scientists are not sure why these distinct properties exist and how they allow the lithosphere to move over the asthenosphere.
A team of researchers from Japan has studied the effect of water on rocks similar to those found in the asthenosphere. They found that water has a significant effect on the seismic properties of these rocks. It enhances energy dispersion and reduces the rocks’ elastic moduli. The presence of water also weakens the asthenosphere, allowing the lithosphere to move smoothly over it.
These findings suggest that the asthenosphere contains water. This difference in water content between the two layers of the LAB can explain the sharp drops in seismic wave velocity and consistent attenuation observed in the asthenosphere.
The researchers note that further research is needed to explore the effects of iron on the rocks’ properties.
Understanding the presence of water in the asthenosphere can provide insights into volcanic and seismic activities. This study contributes to our understanding of tectonic plate movement and helps us better understand various tectonic activities.
>>Join our Facebook Group be part of community. <<