Эрдэмтэд дэлхийн мантийн 270 сая жилийн хувьслыг дуурайлган үзүүлснээр далайн ёроолд орших олон арван мянган уулын гарал үүслийг шинээр тодорхойлжээ.
Хятадын Шинжлэх ухааны академийн Геологи, геофизикийн хүрээлэнгийн профессор Лиү Ли-Жүний удирдсан баг компьютерын өндөр нарийвчлалтай загварчлал ашиглан мантийн дулааны үйл явцыг судалсан байна. “Nature Geoscience” сэтгүүлд зургаадугаар сарын 10-нд нийтлэгдсэн уг судалгаагаар далайн ёроолын 40 мянга гаруй уул нь зөвхөн “халуун цэг”-ийн онолоор тайлбарлагдах боломжгүйг тогтоожээ. Өмнө нь зөвхөн 50 орчим уулын гинжин хэлхээг мантийн урсгалтай холбон тайлбарладаг байсан бол энэхүү шинэ загвар нь тархмал байрлалтай уулсын үүслийг илүү тодорхой болгосон байна.
Судалгааны үр дүнд мантийн гүнээс дээшлэх халуун материалын урсгал буюу “мантийн өд”-үүд нь дэлхийн царцдасын дор дулааны бүсүүдийг үүсгэдэг болохыг тогтоожээ. Эдгээр “исгэх бүс” гэж нэрлэгдэх халуун цэгүүд нь тектоник хавтангуудын дор удаан хугацаанд хадгалагдаж, олон цэгт галт уулын идэвхжил үүсгэн, тархмал уулсыг бий болгодог байна. Мөн мантийн өдүүд дээшлэх явцдаа салж хуваагдах нь галт уулын олон төв үүсэхэд нөлөөлдөг болохыг загварчлал харуулжээ.
Энэхүү судалгаа нь мантийн физик болон гадаргуу дээрх галт уулын үйл ажиллагааны хоорондын уялдааг тайлбарлаж, далайн ёроолын геологийн тогтоцын талаарх ойлголтыг өргөжүүлж байна. Дулааны аномали буюу хэвийн бус халуун бүсүүдийн температур нь далайн ёроолын уулсын өндөртэй шууд хамааралтай болох нь тогтоогдсон нь уг загварын ач холбогдлыг нотлох бас нэгэн баримт болжээ.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A new high-resolution simulation of Earth’s interior is reshaping how scientists explain the origin of tens of thousands of underwater mountains on the ocean floor. The model reconstructs 270 million years of mantle evolution and connects deep thermal processes to both long volcanic chains and scattered seamounts.
Seamounts are one of the most widespread volcanic features on Earth, yet they remain largely invisible because they sit far below sea level. They appear in contrasting forms: some line up into long chains like the Hawaiian–Emperor system, while others stand alone across vast ocean basins. With more than 40,000 identified, they represent a major part of Earth’s volcanism, but their origins are still not fully explained.
For decades, the hotspot hypothesis has been the main explanation for volcanic chains. It describes mantle plumes rising from deep inside Earth and melting rock as tectonic plates move above them. But this idea only covers a small fraction of observed structures. The Institute of Geology and Geophysics of the Chinese Academy of Sciences (CAS) reported that only about 50 seamount chains clearly match this model, leaving most seamounts without a consistent explanation.
A 270-million-year Look Inside Earth’s Mountain System
A team led by Professor Liu Lijun at CAS built large-scale computer simulations that reconstruct mantle dynamics over 270 million years. The study, published in Nature Geoscience on June 10, follows how mantle plumes rise from near the core-mantle boundary and evolve as they move upward.
The model doesn’t just track plume paths. It also shows how these structures interact with surrounding mantle layers over time, allowing researchers to connect deep thermal patterns with present-day seamount locations. The authors noted that this time-evolving approach helps bridge a gap between mantle physics and surface volcanism.
The Pacific Plate is a central example in the reconstruction. Early plume activity there appears to have built up large amounts of heat beneath young oceanic crust, shaping wide regions of the upper mantle over long geological periods.
Hidden Heat Zones That Feed Scattered Volcanoes
A key result of the study is the role of asthenospheric thermal anomalies, regions of unusually high temperature in the upper mantle created by plume-derived heat. The CAS team explained that these zones form when hot material spreads and accumulates beneath moving tectonic plates.
In the Western Pacific, the simulations show a close match between these thermal zones and clusters of scattered seamounts. The paper explained that this pattern suggests volcanic activity does not always require a single narrow plume. Instead, broad hot regions in the mantle can generate multiple eruption points spread across large areas.
“Most Cretaceous seamounts in the Pacific Ocean formed above major plume heads ponding beneath the young oceanic plate, where the resulting hot zones fuelled widespread intraplate volcanism without age progression,” thr authors noted.
The researchers describe these regions as “seamount brewing zones,” where long-lasting heat increases the likelihood of volcanic formation in different locations rather than along a single line. It shifts the picture away from tidy volcanic chains as the only dominant structure.
How Mantle Plumes Break Apart and Remain Active?
The study also found that mantle plumes can break apart during their ascent. The simulations show splitting either near the deep mantle source or within the mantle transition zone. This produces secondary plumes and increases the number of volcanic centers.
That mechanism helps explain why many seamounts appear isolated, without clear alignment to a volcanic chain. Instead of a single continuous plume, multiple smaller upwellings can form and evolve independently over time.
Another important pointed is the persistence of heat in the asthenosphere. The model shows that thermal anomalies can remain for long periods, slowly shifting with mantle flow. The researchers also report a clear relationship between the temperature of these anomalies and seamount height: warmer regions tend to correspond to taller volcanic structures.
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