Researchers made use of earthquake reading technology to have a better idea of the Earth’s inner appearance. It seems that the core is made up of two layers, an outer core, and an inner core, both of which differ in composition and structure.
The Earth’s inner-inner core, beyond the reach of humans. Photo credits: Lachina Publishing Services
The depths of our planet remain inaccessible to us. Though scientists have documented what might possibly be beneath its outer surface, no journey to the center of the Earth can be entertained as plausible idea, or endeavour. However, researchers have made do with their resources and gleaned much data as to what is lying beneath our feet. It has long been thought that our planet’s core (the innermost ‘layer’) is made of solid iron. Now, it seems that the latter has a smaller core – an inner-inner core.
Seismic waves emitted by earthquakes have allowed scientists to detect the presence of the inner-inner core. Researchers from the University of Illinois and Nanjing University have made use of earthquake reading technology to get to their ends. Their findings were published in the journal, Nature Geoscience. They recorded seismic waves forming ripples that result in the ringing of the inside of the Earth, much like a bell. They have used this technology to “peer into the center of the Earth”.
The Earth has many layers: the crust, the mantle, and the core. The core is seemingly not a solid single layer. Rather, it has two layers: an outer inner core and an inner-inner one. The former might be made of molten iron and the latter of solid iron.
The inner-inner core is around half of the diameter of the whole inner core. The inner core revealed its outer part being around the size of the Moon. The middle layer though has dramatically different structure and contents.
The iron crystals found in the different spots were found to be in different directions. Those situated in the outer layer of the core faced north and south while those from the inner layer pointed east and west. The iron crystals located in the inner-inner core probably behave differently.
The difference between the layers suggests that the outer and inner layers of the core were created in a different form or were part of different phases.
The researchers affirmed that the results of their study indicate that the inner core might have evolved during the tectonic changes that occurred in the early history of Earth.