Earthquake swarms in non-volcanic regions: What fluids have to say
Earthquake swarms in non-volcanic regions: What fluids have to say
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DOI：
10.1029/2009gl039615
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发表时间：
2009-09-04
影响因子：
5.2
通讯作者：
Strauch, Gerhard
中科院分区：
文献类型：
--
作者：
Braeuer, Karin;Kaempf, Horst;Strauch, Gerhard
产生震群的详细过程是复杂的，尚未完全了解。大多数地震群发生在火山地区和大洋中的裂谷。在这里，我们报告新的He-3/He-4数据的自由气体监测在富含CO2的脱气位置靠近Novy Kostel焦点区（NKFZ）位于西部埃格裂谷。NKFZ以地震群的复发而闻名，震源区在6至12公里深之间。在NKFZ附近的脱气位置，在过去的15年里观察到幔源氦的逐渐增加-实际上是中欧最高的He-3/He-4比值（> 6 Ra）。He-3/He-4异常指示岩浆活动。我们假设，2008年10月最新的强震群是由一个隐藏的岩浆侵入过程，从上地幔到下地壳，已表示了三个月的持续增加的He-3/He-4的比例在2006年春季在所有脱气地点附近的NKFZ。引文：Brauer，K.，H. Kampf和G. Strauch（2009），Earthquake swarm in non-volcanic regions：What fluids have to say，Geophys.保留信函：36，L17309，doi：10.1029/2009GL039615。
The detailed processes generating earthquake swarms are complex and not fully understood. Most earthquake swarms occur in volcanic regions and mid-ocean rifts. Here, we report new He-3/He-4 data of free gases monitored at CO2-rich degassing locations close to the Novy Kostel focal zone (NKFZ) located in the western Eger rift. The NKFZ is known for the recurrence of earthquake swarms at which the focal zone ranges between 6 and 12 km depth. At degassing locations neighboring to the NKFZ a progressive increase of mantle-derived helium has been observed during the last 15 years - actually the highest He-3/He-4 ratios (>6 Ra) in Central Europe. The He-3/He-4 anomalies indicate hidden magmatic activity. We assume that the latest strong earthquake swarm in October 2008 was initiated by a hidden magma intrusion process from the upper mantle into the lower crust that has been indicated by a three month lasting increase of the He-3/He-4 ratios in spring 2006 at all degassing locations near the NKFZ. Citation: Brauer,K., H. Kampf, and G. Strauch (2009), Earthquake swarms in non-volcanic regions: What fluids have to say, Geophys. Res. Lett., 36, L17309, doi:10.1029/2009GL039615.