深部マグマだまりが火山噴火予測を改善する可能性(Clues from deep magma reservoirs could improve volcanic eruption forecasts)

ad

2024-05-10 インペリアル・カレッジ・ロンドン(ICL)

火山噴火は、地域住民や環境に大きな影響を与える危険性があります。従来、火山の活動や地殻上層の溶岩に基づいて予測されていましたが、新研究では地殻深部からの情報が重要とされています。インペリアル・カレッジ・ロンドンとブリストル大学の研究者たちは、火山噴火の頻度や規模が地下深くのマグマ形成に関連していることを示し、より正確な噴火予測が可能になると考えています。この発見は、地域社会の安全確保と環境リスクの軽減に寄与すると期待されています。

<関連情報>

大規模火山噴火の規模、頻度、組成を支配する火源貯留層 Source reservoir controls on the size, frequency, and composition of large-scale volcanic eruptions

CATHERINE A. BOOTH, MATTHEW D. JACKSON, R. STEPHEN J. SPARKS, AND ALISON C. RUST
Science Advances  Published:10 May 2024
DOI:https://doi.org/10.1126/sciadv.add1595

Abstract

Large-scale, explosive volcanic eruptions are one of the Earth’s most hazardous natural phenomena. We demonstrate that their size, frequency, and composition can be explained by processes in long-lived, high-crystallinity source reservoirs that control the episodic creation of large volumes of eruptible silicic magma and its delivery to the subvolcanic chamber where it is stored before eruption. Melt percolates upward through the reservoir and accumulates a large volume of low-crystallinity silicic magma which remains trapped until buoyancy causes magma-driven fractures to propagate into the overlying crust, allowing rapid magma transfer from the reservoir into the chamber. Ongoing melt percolation in the reservoir accumulates a new magma layer and the process repeats. Our results suggest that buoyancy, rather than crystallinity, is the key control on magma delivery from the source reservoir. They identify an optimum reservoir size for the largest silicic eruptions that is consistent with data from natural systems and explain why larger magnitude eruptions are not observed on Earth.

ad
1702地球物理及び地球化学
ad
ad


Follow
ad
タイトルとURLをコピーしました