Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA
Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA
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美国黄石公园的树轮 14C 将地震群与二氧化碳峰值联系起来
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
H. Heasler
中科院分区：
文献类型：
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作者：
W. Evans;D. Bergfeld;J. McGeehin;J. King;H. Heasler
解释黄石火山口（美国西部）的浅层地震活动和膨胀-收缩周期的机制通常会引起岩浆衍生的盐水或气体从韧性带的偶发性逃逸，但没有相关的变化，在表面流出的岩浆成分被记录在案。我们对来自火山口内泥火山热区的树芯中的单个年轮进行了分析，将14 C的急剧下降25%与1978年的当地地震群联系起来。这意味着二氧化碳排放量增加了五倍，这清楚地将群震活动与岩浆衍生流体的上流联系起来，并表明岩浆二氧化碳脉冲可以迅速穿过5公里厚的脆性带，甚至穿过黄石公园巨大的热液储层。1978年的地震早于每年的形变调查，但随后的地震群和形变变化之间公认的联系表明，二氧化碳可能会推动这两个过程。
Mechanisms to explain swarms of shallow seismicity and inflation-deflation cycles at Yellowstone caldera (western United States) commonly invoke episodic escape of magma-derived brines or gases from the ductile zone, but no correlative changes in the surface efflux of magmatic constituents have ever been documented. Our analysis of individual growth rings in a tree core from the Mud Volcano thermal area within the caldera links a sharp ∼25% drop in 14 C to a local seismic swarm in 1978. The implied fivefold increase in CO 2 emissions clearly associates swarm seismicity with upflow of magma-derived fluid and shows that pulses of magmatic CO 2 can rapidly traverse the 5-km-thick brittle zone, even through Yellowstone9s enormous hydrothermal reservoir. The 1978 event predates annual deformation surveys, but recognized connections between subsequent seismic swarms and changes in deformation suggest that CO 2 might drive both processes.