Seismically enhanced solute fluxes in the Yangtze River headwaters following the AD 2008 Wenchuan earthquake
Seismically enhanced solute fluxes in the Yangtze River headwaters following the AD 2008 Wenchuan earthquake
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DOI：
10.1130/g37246.1
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发表时间：
2016-01-01
期刊：
影响因子：
5.8
通讯作者：
Wang, Xulong
中科院分区：
文献类型：
--
作者：
Jin, Zhangdong;West, A. Joshua;Wang, Xulong
大地震改变了地球表面的物理和化学过程，引发了山体滑坡，使岩石破裂，改变了大范围的渗透率，并影响了水文路径。由此产生的对全球化学循环的影响尚不完全清楚。这里我们展示了公元2008年汶川7.9度大地震后，位于长江(中国)源头的闽江的溶解化学变化。震后闽江地区的总溶质通量增加，与之类似的是Na~*/Ca比值(其中Na~*是经大气和蒸发岩贡献校正后的Na~+)和0.000644/-0.000146的锶-87/锶-86同位素比值的增加。这些变化与硅酸盐来源的贡献增加相一致。我们推测，硅酸盐碱度的二氧化碳消耗速率增加了4.3+/-0.4倍。如果类似的变化与其他大地震有关，那么增加的溶质输出可能会直接将构造活动与风化和碱度通量联系起来，这些通量为生态系统提供养分，影响海水化学演变，并引导地球的长期碳循环和气候。
Large earthquakes alter physical and chemical processes at Earth's surface, triggering landslides, fracturing rock, changing large-scale permeability, and influencing hydrologic pathways. The resulting effects on global chemical cycles are not fully known. Here we show changes in the dissolved chemistry of the Min Jiang, a river in the Yangtze River (China) headwaters, following the A.D. 2008 M-w 7.9 Wenchuan earthquake. Total solute fluxes transported by the Min Jiang increased after the earthquake, accompanied by an similar to 4x increase in Na*/Ca ratios (where Na* is Na+ corrected for atmospheric and evaporite contributions) and a 0.000644 +/- 0.000146 increase in Sr-87/Sr-86 isotopic ratios. These changes are consistent with enhanced contribution from silicate sources. We infer that the CO 2 consumption rate via silicate-derived alkalinity increased 4.3 +/- 0.4 times. If similar changes are associated with other large earthquakes, enhanced solute export could directly link tectonic activity with weathering and alkalinity fluxes that supply nutrients to ecosystems, influence seawater chemistry evolution, and steer Earth's long-term carbon cycle and climate.