Компьютерын загварчлалын үр дүнгээр Дэлхийн дотоод цөмд өвөрмөц шинж чанартай устөрөгч оршин байж болзошгүйг тогтоов.
Proceedings of the National Academy of Sciences сэтгүүлд нийтлэгдсэн шинэ судалгаагаар Дэлхийн гүнд, газрын гадарга дээр үл олдох устөрөгчийн нэгэн сонирхолтой төлөв байдал оршин байж болохыг эрдэмтэд таамаглаж байна. Супер ионт гэж нэрлэгдэх энэхүү төлөв нь хатуу бүтэцтэй хэдий ч шингэн мэт урсгалтай, цахилгаан дамжуулах чадвартай байдаг ажээ. Судлаачид Дэлхийн цөмийн үндсэн бүрэлдэхүүн болох төмөр болон устөрөгчийн хайлшийн төлөвийг компьютерын загварчлалаар дамжуулан асар өндөр даралт, температурын нөхцөлд судалсан байна.
Туршилтын хүрээнд төмөр-устөрөгчийн хайлшийн хоёр өөр бүтцийг шинжилснээс гексагонал (HCP) бүтэц нь Дэлхийн дотоод цөмийн нөхцөлд илүү тогтвортой байх магадлалтай болох нь харагджээ. Харин куб (BCC) бүтэц нь өндөр температур болон устөрөгчийн агууламж ихтэй нөхцөлд тогтвортой байж болох ч, тухайн нөхцөлд материал хайлах хандлагатай байдаг тул бодит байдалд давамгайлах боломж бага юм. Судалгаагаар устөрөгч нь дотоод цөмд жигд бус тархалттай байж болох бөгөөд төвийн хэсгээс гаднах хил хязгаар руу чиглэн шилжих хөдөлгөөн хийдэг байж болзошгүй гэж үзжээ.
Энэхүү үйл явц нь Дэлхийн соронзон орныг үүсгэгч геодинамогийн ажиллагаанд шаардлагатай химийн хөвөх чадварыг хангахад нөлөөлөх боломжтой юм. Устөрөгчийн энэхүү шилжилт хөдөлгөөн нь зөвхөн цөмийн талстжилтын үйл явцтай холбоогүй бөгөөд цөмийн бүсүүдийн хоорондох бодисын тасралтгүй солилцоог илэрхийлж байна. Судлаачид устөрөгчөөс гадна хүчилтөрөгч, нүүрстөрөгч зэрэг хөнгөн элементүүд ч ижил төстэй замаар тархаж, Дэлхийн цөмийн бүтэц, хувьсалд нөлөөлдөг байж болзошгүйг онцоллоо.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A new study suggests that Earth’s inner core may contain a bizarre form of hydrogen that behaves unlike anything found at the surface. Known as superionic hydrogen, this material can flow like a liquid while still keeping a solid structure and carrying electricity under extreme conditions.
Deep inside Earth, pressure and heat create an environment unlike any place humans can reach. The planet’s core remains hidden thousands of kilometers below the surface, where familiar elements can take on unexpected forms.
Scientists have long studied what lies inside this inaccessible region, especially the role of lighter elements mixed with the core’s main ingredient, iron. Hydrogen has attracted attention because it could influence the core’s composition and the way materials move inside the planet.
A study published in Proceedings of the National Academy of Sciences suggests that superionic hydrogen could be present in Earth’s interior, even though this unusual state of matter does not exist naturally anywhere else on the planet. Researchers used computer simulations to examine how hydrogen behaves when combined with iron under the crushing pressures and intense temperatures found deep underground.
A Hidden Hydrogen State Inside Earth’s Core
The research team tested different models of iron-hydrogen alloys to understand how hydrogen might exist inside the inner core. Instead of forming a separate layer, hydrogen could move through the atomic structure of iron, creating a material with unusual properties.
The simulations focused on two possible arrangements: the hexagonal close-packed (HCP) structure and the body-centered cubic (BCC) structure. Both describe different ways iron atoms could organize themselves while allowing hydrogen atoms to move through the structure.
The results showed that the BCC form is less stable because it has higher free energy and is more reactive. The HCP form appears better suited to the conditions inside Earth’s inner core.
The researchers found that the BCC structure could become more stable at temperatures above 6,400 kelvin and hydrogen concentrations higher than 20 percent under pressures of about 3.6 million atmospheres. But the study indicates that these conditions may also push the material toward melting, making the BCC phase unlikely to dominate.
“Our calculations show that hydrogen can stabilize a superionic BCC phase at sufficiently high temperature and hydrogen content,” the researcherswrote. “However, this stability field is superseded by melting, so only the superionic HCP phase coexists with the liquid in the Fe–H system.”
Hydrogen May Move Between Earth’s Inner And Outer Core
The study also found that hydrogen is probably not spread evenly throughout the inner core. The simulations revealed a hydrogen concentration gradient, with more hydrogen near the outer parts of the center and less toward the center.
This difference could drive superionic hydrogen toward the boundary between the inner core and the outer core. When it reaches this region, the hydrogen may lose its superionic behavior and become part of a liquid mixture.
The researchers explained that this exchange is not only caused by the gradual crystallization of the center. Their work shows that hydrogen can also move continuously between different regions of the core. The inner core is still growing as material solidifies, at a rate of around 1 millimeter per year. This process is linked with the movement of light elements, including hydrogen, throughout Earth’s deepest layers.
Earth’s Magnetic Field Gets a New Clue
The movement of hydrogen and other light elements may help explain why different parts of the core have different compositions. The researchers suggest that these movements can contribute to chemical buoyancy, which helps provide energy for the geodynamo that generates Earth’s magnetic field.
The study found that temperature appears to control where different hydrogen forms exist inside the core more than pressure does. Even though pressure remains enormous throughout the region, changes in temperature determine which structures are stable.
The authors also noted that the same process could affect other light elements, including oxygen and carbon, which may also be present in Earth’s core. The also added that:
“Our results, therefore, demonstrate that the nonuniform distribution of superionic hydrogen in the [inner core] is a direct consequence of equilibrium thermodynamics. This mechanism may also apply to the distribution of other light elements, influencing [the] core’s composition, dynamics, and evolution.”
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