The Earth’s Mantle
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Geology seeks to understand the structure and behavior of Earth’s interior, and the mantle plays a central role in this system.
Located between the crust and the core, the mantle accounts for the majority of Earth’s volume.
Although it is composed largely of solid rock, the mantle does not behave as a rigid body.
Over geological time, its material can slowly flow under intense heat and pressure.
The mantle is commonly divided into the upper mantle and the lower mantle, separated by zones of changing mineral structure.
In the upper mantle, high temperatures cause rocks to deform plastically rather than fracture.
This slow movement drives convection currents, which transfer heat from Earth’s interior toward the surface.
These currents are a key force behind plate tectonics, influencing the movement of continents and the formation of geological features such as mountains and volcanoes.
Advances in seismic technology have allowed scientists to study the mantle indirectly.
By analyzing how seismic waves travel through Earth during earthquakes, researchers can infer variations in temperature, composition, and density within the mantle.
Differences in wave speed suggest that the mantle is not uniform but contains regions with distinct physical properties.
Despite these insights, many aspects of the mantle remain uncertain.
Direct sampling is impossible due to extreme depths and conditions.
As a result, scientists rely on models and indirect evidence, continuously revising their understanding as new data emerges.
The mantle, though hidden from view, remains essential to explaining Earth’s dynamic surface and long-term evolution.
摘要
地函位於地殼與地核之間，占地球體積最大部分，雖由固態岩石構成，卻能在高溫與高壓下長期緩慢流動。
上地函的對流運動負責傳遞地球內部熱能，是板塊構造與地表地質活動的重要動力來源。
科學家透過分析地震波間接推測其溫度與密度差異，逐步理解地球內部結構與演化過程。