The relationship between volcanism and global climate changes in the Tropical Western Pacific over the mid-Pleistocene transition: Evidence from mercury concentration and isotopic composition
The relationship between volcanism and global climate changes in the Tropical Western Pacific over the mid-Pleistocene transition: Evidence from mercury concentration and isotopic composition
复制标题
更新世中期热带西太平洋火山活动与全球气候变化的关系：来自汞浓度和同位素组成的证据
DOI：
10.1016/j.scitotenv.2022.153482
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发表时间：
2022
影响因子：
9.8
通讯作者：
Qi Han
中科院分区：
文献类型：
--
作者：
Yipeng Wang;Wenlong Pei;Jialei Yang;Yujin Fan;Rui Zhang;Tiegang Li;James Russell;Fan Zhang;Xiaoxiao Yu;Junjie Hu;Yuehua Song;Zhiyong Liu;Minglei Guan;Qi Han
火山是地球系统的一个重要组成部分，在大的空间和时间尺度上影响海洋与大气之间的相互作用。热带西太平洋是一个火山活动区，对全球气候变化具有重要影响。然而，高分辨率的火山活动在这一地区的连续记录是缺乏的，导致显着的不确定性之间的耦合地球深部，气候变化和大气CO2在TWP。为了解决这一问题，汞（Hg）水平，同位素组成，汞/总有机碳（Hg/TOC）的比例确定在站点U1486跟踪火山活动在整个中更新世过渡（MPT）从1.3百万年到0.6百万年。我们的研究结果异常高的汞浓度和汞/总有机碳的比例提供了整个MPT随时间变化的火山活动的证据。汞同位素的特征是Δ 199Hg值接近于零，这与火山活动是沉积物中汞的主要来源相一致。汞/总有机碳比值的光谱分析表明，在~100 kyr和~23 kyr时具有显著的周期性，在~41 kyr时信号较弱，与米兰科维奇周期一致。对Hg/TOC和LR 04 δ 18O叠加记录的交叉谱分析表明，火山活动的峰值比温度最低值滞后约6kyr，并且比称为冰川终止的δ 18O最低值早约14kyr ± 2kyr。火山活动在这个网站的记录也是一致的大气CO2的显着上升和整个MPT的底栖生物碳同位素的负偏移。这项研究提供了火山活动，气候变化和大气CO2之间的反馈TWP的直接沉积证据。
Volcanoes are a significant component of the Earth system, influencing the interaction between oceans and the atmosphere over large spatial and temporal scales. Being a volcanically dynamic region, the Tropical Western Pacific (TWP) can significantly impact variations in global climate. However, high-resolution continuous records of volcanic activity in this region are lacking, resulting in significant uncertainties regarding the coupling between the deep earth, climate changes, and atmospheric CO2in the TWP. To address this issue, mercury (Hg) levels, isotopic compositions, and Hg/total organic carbon (Hg/TOC) ratios were determined at site U1486 to track volcanic activity throughout the mid-Pleistocene transition (MPT) from 1.3 Myr to 0.6 Myr. Our results of anomalously high Hg concentrations and Hg/TOC ratios provide evidence of time-varying volcanism throughout the MPT. Mercury isotopes in the Hg-enriched sediments were characterized by near-zero Δ199Hg values, which is consistent with volcanism acting as the primary source of Hg to the sediments. Spectral analysis of the Hg/TOC ratio showed significant periodicity at ~100 kyr and ~ 23 kyr as well as a weaker signal at ~41 kyr consistent with Milankovitch cycles. A cross spectral analysis of Hg/TOC and the LR04 δ18O stack record suggests that the peak in volcanism lags the temperature minimum by ~6 kyr, and occurs prior to the δ18O minimum known as the glacial termination by ~14 ± 2 kyr. The records of volcanic activity in this site are also consistent with a prominent rise in atmospheric CO2and negative excursion of benthic carbon isotopes throughout the MPT. This study provides direct sedimentary evidence in the TWP of the feedback between volcanic activity, climate change and atmospheric CO2.