Productivity control of fine particle transport to equatorial Pacific sediment
Productivity control of fine particle transport to equatorial Pacific sediment
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DOI：
10.1029/1998gb001102
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发表时间：
2000-09
影响因子：
5.2
通讯作者：
E. Thomas;K. Turekian;K. Wei
中科院分区：
文献类型：
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作者：
E. Thomas;K. Turekian;K. Wei
3He（来自宇宙尘埃）、230Th（在水柱中产生）、重晶石（有机物衰变过程中在水柱中产生）以及 Fe 和 Ti（随风载尘埃到达）的积累率在赤道太平洋核心（TT013-PC72；北纬 01.1°，西经 139.4°；水深 4298 m）均呈正相关。这些积累速率也与非碳酸盐物质的积累速率正相关。它们与构成沉积物主体的碳酸盐的质量积累率没有显着相关。因此，来自不同来源的这些不同成分的积累率的波动必定是由于海洋内某些过程的变化造成的，而不是由于其原始来源的变化造成的。海底洋流对沉积物的聚焦已被提议作为这一过程[Marcantonio et al., 1996]。我们认为，所有这些成分的积累率的变化主要与赤道太平洋上升流区域生产力的变化和新鲜浮游植物碎屑（在腐烂时释放 Ba）清除颗粒（3He、230Th、Fe、Ti）的变化有关。我们推测，由于赤道太平洋生产力是全球海洋生产力的主要组成部分，其随时间的变化可能反映在大气中甲磺酸（二甲硫醚的大气反应产物，由海洋浮游植物产生）水平的变化，并记录在南极冰芯中。
Accumulation rates of 3He (from cosmic dust), 230Th (produced in the water column), barite (produced in the water column during decay of organic matter), and Fe and Ti (arriving with wind‐borne dust) all are positively correlated in an equatorial Pacific core (TT013‐PC72; 01.1°N, 139.4°W; water depth 4298 m). These accumulation rates are also positively correlated with the accumulation rates of noncarbonate material. They are not significantly correlated to the mass accumulation rate of carbonate, which makes up the bulk of the sediment. The fluctuations in accumulation rates of these various components from different sources thus must result from variations in some process within the oceans and not from variations in their original sources. Sediment focusing by oceanic bottom currents has been proposed as this process [Marcantonio et al., 1996]. We argue that the variations in the accumulation rates of all these components are dominantly linked to changes in productivity and particle scavenging (3He, 230Th, Fe, Ti) by fresh phytoplankton detritus (which delivers Ba upon its decay) in the equatorial Pacific upwelling region. We speculate that as equatorial Pacific productivity is a major component of global oceanic productivity, its variations over time might be reflected in variations in atmospheric levels of methanesulfonic acid (an atmospheric reaction product of dimethyl sulfide, which is produced by oceanic phytoplankton) and recorded in Antarctic ice cores.