When it comes to the things below our Earth’s crust, we don’t tend to think too much about them, but perhaps we should. There are things below our feet that we could never imagine and well, that much is becoming more and more apparent.
A study published in recent times that came out just this past year really brings a lot to the table in regard. Basically, this study suggests that there could be something hiding within our planet’s core. Yes, the core. While we don’t know much about all of this just yet, as time passes and more research is done there is no telling what we may end up uncovering.
The abstract of this study goes as follows and was posted under the title ‘Evidence for the Innermost Inner Core: Robust Parameter Search for Radially Varying Anisotropy Using the Neighborhood Algorithm’:
The model of cylindrical anisotropy in the inner core (IC) states that seismic rays traveling parallel to the Earth’s rotational axis travel faster than those parallel to the equator. There have been continuing discrepancies in estimates of the strength and orientation of anisotropy, with some evidence suggesting that such a model may not be supported by available data. Here, we scrutinize the radial dependence of anisotropy within the IC, where the nature of anisotropy has been shown to change anywhere between a 300 and 800 km radius. We use recent time travel data from the International Seismological Centre in conjunction with the neighborhood algorithm to provide a robust means of testing this idea, through an examination of an ensemble of models that satisfactorily fit the data. This can be done with no explicit regularization and without the need for subjective choices associated with binning of phase data. In addition, uncertainty bounds are calculated for anisotropic parameters using a likelihood ratio approach. We find evidence to suggest that commonly employed spatial averaging (binning) methods may be detrimental to obtaining reliable results. We conclude that there is no significant change in the strength of anisotropy with depth in the IC, Instead, we find a change in the slow direction of anisotropy to 54 degrees within the innermost IC at an 650 km radius with fast direction parallel to the Earth’s rotational axis.
I know, that in itself sounds pretty confusing, but it brings a lot to the table. Basically, this is seemingly confirming the existence of some kind of innermost core present within our core itself. This meaning that there has to be some kind of change that went down in the past.
The Australian National University wrote as follows on the topic:
Lead author of the study, PhD researcher Joanne Stephenson, says while this new layer is difficult to observe, its distinct properties may point to an unknown, dramatic event in the Earth’s history.
“We found evidence that may indicate a change in the structure of iron, which suggests perhaps two separate cooling events in Earth’s history,” Ms Stephenson said.
“The details of this big event are still a bit of a mystery, but we’ve added another piece of the puzzle when it comes to our knowledge of the Earths’ inner core.”
Ms Stephenson says that investigating the structure of the inner core can help us understand more about the Earth’s history and evolution.
“Traditionally we’ve been taught the Earth has four main layers: the crust, the mantle, the outer core and the inner core.
“The idea of another distinct layer was proposed a couple of decades ago, but the data has been very unclear.