DATE2025.04.25 #Press Releases
New numerical simulation reveals the long-lasting volcanism of the Moon
-- The volcanism is aided by the switch in dominant mechanisms of magma ascent --
Summary
A research group led by Dr. Ken'yo U of the Department of Earth Sciences and Astronomy at the University of Tokyo, in collaboration with Dr. Gaku Nishiyama of the Department of Earth and Planetary Science at the University of Tokyo, has revealed that the long-lasting volcanism of the Moon is caused by a switch in the dominant mechanisms of magma ascent (Figure).
Geological observations of the Moon have shown that active volcanism took place at 3-4 Ga and continued for billions of years in the region called the Procellarum KREEP Terrane (PKT). To understand this volcanic history, the group calculated a 2-D model of magmatism and mantle convection, considering a locally enriched area of heat-producing elements (HPEs) beneath the crust to model this localized long-lasting volcanism in the PKT.
Their results show that localized volcanism continues for billions of years owing to ascending partially molten plumes. However, the mechanism of ascent of plumes changed with time. The early volcanic activity is caused by the ascent of partially molten plumes that are generated by strong internal heating at the base of the mantle. On the other hand, the later activity is driven by counterflows of sinking basaltic blobs formed by the early magmatism. The simulations also suggest the importance of an HPE-enriched area for the ascent of magma driven by counterflows to the surface.
Their model suggests that later plumes caused by sinking basaltic blobs are the cause of the long-lasting volcanism in the PKT. The implications of the simulations, e.g., the existence of basaltic blobs in the lunar uppermost mantle, provide motivation for future exploration of the Moon. Their results would be critical to the upcoming scientific exploration of the planned lunar seismometer network.
Figure: Snapshots of the distributions of (top) temperature and (bottom) magma fraction for around 3 Ga.
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Journal
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Journal Name Geophysical Research LettersTitle of paper