The core of the earth is like the “engine” of the earth. Once it cools down, the earth will shut down, and it will soon become as lifeless as Mars.
So what’s going on with the Earth‘s core? How hot is it? Is the earth really running out of electricity?
Discovery and Research of the Earth’s Core
As the center of the earth, the core of the earth is not small, with a radius of about 3470 kilometers and a very high density, with an average weight of about 10.7 grams per cubic centimeter. According to data, the mass of the earth’s core is 31.5% of the total mass of the earth, and its volume is 16.2% of the earth’s volume. It can be seen that, don’t think of it as a mini “core”.
The size of the earth’s core is not small, and the density is very high
People’s understanding of the temperature of the Earth’s core has also gone through a tortuous process. For example, in 1993, the scientist Boehler published research results in the journal “Nature”, believing that the temperature at the interface between the inner and outer cores of the Earth’s core was close to 5000K. In 2013, another study The author published a paper in “Science” in 2013, pointing out that the temperature of the earth’s core is as high as 6000K.
The earth’s core can be roughly divided into two layers. Its inner core is solid and its volume is very small, only about 1% of the earth’s. The outer core is liquid and flows slowly. Judging from the current exploration situation, the dividing line between the solid inner core and the liquid outer core of the earth is about 5155 kilometers, which is still very deep.
Many people think that exploring the core of the earth seems easier than observing the vast universe with the naked eye. Therefore, after the ancients had the intention of “asking the earth”, they should have quickly solved the puzzle of the earth’s core. But in fact, from a certain point of view, the exploration of the earth’s core is even more difficult than the exploration of the universe. Because 200 years ago, we knew nothing about the layers of the earth’s interior.
The earth’s core was discovered by chance. When people studied earthquakes in the 19th century, they found that the transmission speeds of compression waves and shear waves were significantly different, and compression waves were often superior. And there is another significant difference between the two, that is, shear waves cannot propagate through liquids.
In this way, people continue to trace the roots and start using seismic waves to study the structure of the earth’s interior. For example, in 1906, British scientist Richard Dixon Oldham, from seismic records and related research, proved that the velocity of seismic waves will decrease with the increase of depth, which means that the structure inside the earth is layered, it is not Completely solid or liquid.
As research progressed, the original assumption was that the Earth’s core was liquid because shear waves couldn’t travel through it. But later, everyone discovered that things were not so simple, because there is actually a solid inner core wrapped inside the liquid core layer.
The data shows that in 1936, the Danish female scientist Inge Lehmann discovered a new seismic phase in the compression wave shadow area. She proposed that this must be the reflection of another medium layer in the earth’s core, indicating that the earth’s core has a double-layer structure, and the outer core is liquid , the core is solid. After Lehmann, the two-layer core model became the accepted model.
We can use the common “Ferrero chocolate” as an analogy in our daily life. The solid outer layer of chocolate is the crust and mantle, and the outer part of the sandwich is a soft liquid, which is the outer core. The “nut” in the center is naturally It is the inner core.
In addition, people have also discovered during research that the activities of the liquid outer core will form hot mantle plumes at the boundary between the core and the mantle. start exercising. There are also studies that believe that the existence of the outer core has created the earth’s magnetic field, and the magnetic field protects the earth and makes it have the conditions to breed life.
It is not difficult to see that the earth’s core is still very critical to the earth, and it is for this reason that people pay great attention to the situation of the earth’s core. Previously, a Swiss research team discovered the above situation while monitoring the status of the earth’s core.
Is Earth’s core cooling faster?
Many people are curious, how did the research team discover that the core of the earth is cooling? Could it be that a thermometer was built to measure it?
Obviously unlikely. In fact, researchers at the Zurich University of Technology in Switzerland used minerals at the junction between the core and the mantle as reference objects in their experiments.
The mineral, called Brinellite, conducts heat so well that people can estimate the temperature of the Earth’s core by measuring the thermal conductivity of Brinellite. If the temperature of the earth’s core has been maintained at a high level, then the thermal conductivity will remain high. On the contrary, it proves that the temperature of the earth’s core is cooling down.
When you understand this mechanism, you can understand why Swiss scientists believe that the earth’s core is about to “run out of power”. According to the data, the researchers found that the thermal conductivity of Brinellite was higher than expected, about 1.5 times higher than expected. This means that heat conduction that used to occur in this area will be more pronounced.
The more significant heat conduction would inadvertently increase the mantle convection, which would eventually allow the core to cool faster. It can be seen that according to the latest model, the cooling rate of the earth’s core is much faster than previously estimated. Although we can’t predict at what stage the temperature of the earth’s core will be lost, it must have been much worse than before .
In addition, people also found that when the cooling rate is accelerated, some mineral phases at the boundary will change. For example, the brinellite we mentioned above will transform into a perovskite phase mineral. Because of this, the researchers believe that the rate at which the core cools can also be estimated by estimating the proportion of perovskite-phase minerals in the boundary between the mantle and the core.
It is worth mentioning that many people are afraid that the cooling of the earth’s core will eventually affect the survival of human beings. After all, even if there is no volcanic activity and plate movement, it will not have much impact on people, but once the “engine” stops and the magnetic field disappears, the problem becomes very serious.
So, will the acceleration of the cooling rate of the earth’s core cause the terrible consequences that people imagine?
Is core cooling really that scary?
You don’t have to worry too much, because even if the cooling rate is faster than expected, it is difficult to cause an impact during human survival. After all, such changes on the earth often take hundreds of millions of years as an interval, and human civilization may not survive that time.
The change of the earth is often based on the interval of hundreds of millions of years, so the impact of the cooling of the earth’s core will not appear so quickly
If we are really lucky enough to survive until the day when the core of the earth is completely cooled, we should have mastered higher technology and can escape from the earth at any time. At that point, its impact will be negligible.
However, this research is not useless, because it allows us to see that there are still many unknown things hidden deep in the earth, and some past judgments may be wrong. With more understanding, human beings can also plan early for the future.
GIPHY App Key not set. Please check settings