An alternative mechanism for recent volcanism on Mars
An alternative mechanism for recent volcanism on Mars
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火星近期火山活动的另一种机制
DOI：
10.1029/2007gl030083
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发表时间：
2007
影响因子：
5.2
通讯作者：
D. Breuer
中科院分区：
文献类型：
--
作者：
S. Schumacher;D. Breuer
火星表面的图像表明，火山活动是火星最近发生的过程，最年轻的熔岩流的年龄约为 2 Ma。有趣的是，这些年轻的熔岩流仅限于塔尔西斯和极乐世界古老的大型火山中心，与周围地区相比，这些火山中心的地壳较厚。火山中心的起源及其长期的火山活动通常可以用从核-地幔边界产生的强烈地幔柱来解释。然而，在火星条件下，它们在过去数十亿年中的存在和维持是不确定的。另外，地壳的隔热可能导致长期的火山活动。我们发现，与地幔相比，局部增厚的地壳具有较低的导热性，并且富含放射性热源，导致上地幔显着的横向温度变化，即使在目前的火星地幔中也足以产生部分熔化。
Images of the Martian surface indicate that volcanism is a recent process on Mars with ages of the youngest lava flows of about 2 Ma. Interestingly, these young lava flows are confined to the large, old volcanic centers of Tharsis and Elysium, which exhibit a thickened crust compared to surrounding areas. The origin of the volcanic centers but also their longstanding volcanic activity is often explained by strong mantle plumes arising from the core‐mantle boundary. However, their existence and sustainment during the last few billion years is uncertain under Martian conditions. Alternatively, the thermal insulation by the crust could cause the longstanding volcanic activity. We show that a locally thickened crust, which has a lower thermal conductivity and is enriched in radioactive heat sources in comparison to the mantle, leads to significant lateral temperature variations in the upper mantle sufficient to generate partial melt even in the present Martian mantle.