Submarine hydrothermal activity along the mid-Kermadec Arc, New Zealand: Large-scale effects on venting
Submarine hydrothermal activity along the mid-Kermadec Arc, New Zealand: Large-scale effects on venting
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DOI：
10.1029/2006gc001495
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发表时间：
2007-07-24
影响因子：
3.5
通讯作者：
Lebon, G. T.
中科院分区：
文献类型：
--
作者：
de Ronde, C. E. J.;Baker, E. T.;Lebon, G. T.
[1]长达2,500公里的Kermadec-Tonga弧是地球上最长的海底弧。在这里，我们报告的第二个一系列的巡航，旨在调查大规模的控制活跃的热液喷口在这个弧。2002年的NZAPLUME II号巡航考察了沿着类似于580公里的中Kermadec弧（MKA）的12个海底火山中心，扩展了1999年对260公里的南Kermadec弧（SKA）进行考察的巡航考察。火山中心之间的平均间距从弧后地壳沿着SKA的30 km向北增加，到弧后地壳沿着MKA的45 km，再到MKA与Kermadec海岭相接处的58 km。火山锥在弧后占主导地位，破火山口在克马德克岭占主导地位。喷发的发生率沿着MKA（83%，12个火山中心中的10个）高于SKA（67%，12个火山中心中的8个），但喷发的相对强度（由羽流厚度、面积范围和溶解气体和离子物质的浓度确定）在MKA中一般较弱。这种模式可能反映了SKA下方类似于17公里厚的海洋Hikurangi高原的俯冲。玄武岩块体的俯冲将大大增加下行板块的流体损失，引发上地幔楔的广泛熔融，并激活SKA的热液系统。相反，MKA南部的火山中心缺乏岩浆补充，因此它们的热液系统正在减弱。再往北，MKA中心与Kermadec Ridge合并，更厚（更老）的地壳中积累了更少但更大的岩浆体，确保了更广泛的分离，火山口占主导地位的火山中心。
[1] The 2,500-km Kermadec-Tonga arc is the longest submarine arc on the planet. Here, we report on the second of a series of cruises designed to investigate large-scale controls on active hydrothermal venting on this arc. The 2002 NZAPLUME II cruise surveyed 12 submarine volcanic centers along similar to 580 km of the middle Kermadec arc (MKA), extending a 1999 cruise that surveyed 260 km of the southern Kermadec arc (SKA). Average spacing between volcanic centers increases northward from 30 km on backarc crust along the SKA, to 45 km on backarc crust along the southern MKA, to 58 km where the MKA joins the Kermadec Ridge. Volcanic cones dominate in the backarc, and calderas dominate the Kermadec Ridge. The incidence of venting is higher along the MKA (83%, 10 of 12 volcanic centers) than the SKA (67%, 8 of 12), but the relative intensity of venting, as given by plume thickness, areal extent, and concentration of dissolved gases and ionic species, is generally weaker in the MKA. This pattern may reflect subduction of the similar to 17-km-thick oceanic Hikurangi Plateau beneath the SKA. Subduction of this basaltic mass should greatly increase fluid loss from the downgoing slab, initiating extensive melting in the upper mantle wedge and invigorating the hydrothermal systems of the SKA. Conversely, volcanic centers in the southern MKA are starved of magma replenishment and so their hydrothermal systems are waning. Farther north, where the MKA centers merge with the Kermadec Ridge, fewer but larger magma bodies accumulate in the thicker ( older) crust, ensuring more widely separated, caldera-dominated volcanic centers.