The proximity of hotspots to convergent and divergent plate boundaries
The proximity of hotspots to convergent and divergent plate boundaries
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热点与会聚和发散板块边界的接近程度
DOI：
10.1029/gl016i005p00433
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发表时间：
1989
影响因子：
5.2
通讯作者：
P. Olson
中科院分区：
文献类型：
--
作者：
S. Weinstein;P. Olson
从Morgan（1972）最初列出的19个热点到沃格特（1981）列出的117个热点，对四种不同热点分布的分析表明，热点优先位于发散板块边界附近。这种接近仅偶然发生的概率是相当遥远的，对于所有四个热点分布都小于0.01。同样的分析还表明，热点优先排除在收敛板块边界附近的区域。对于所检查的四个分布中的三个分布，仅偶然发生这种排除的概率为0.1或更小。我们将这种行为解释为大尺度对流环流对地幔柱上升的影响的结果。地幔热柱是热点最可能的来源，它起源于基底热边界层的不稳定性。羽流从收敛边界以下的区域被下降流抑制，并被夹带到扩展中心下方的上升流中。板块尺度的对流环流驱动的俯冲也可能平流地幔热羽向扩张中心。
An analysis of four different hotspot distributions, ranging from Morgan's (1972) original list of 19 to Vogt's (1981) list of 117 reveals that the hotspots are preferentially located near divergent plate boundaries. The probability of this proximity occurring by chance alone is quite remote, less than 0.01 for all four hotspot distributions. The same analysis also reveals that the hotspots are preferentially excluded from regions near convergent plate boundaries. The probability of this exclusion occurring by chance alone is 0.1 or less for three out of the four distributions examined. We interpret this behavior as being a consequence of the effects of large scale convective circulation on ascending mantle plumes. Mantle thermal plumes, the most probable source of hotspots, arise from instabilities in a basal thermal boundary layer. Plumes are suppressed from regions beneath convergent boundaries by descending flow and are entrained into the upwelling flow beneath spreading centers. Plate-scale convective circulation driven by subduction may also advect mantle thermal plumes toward spreading centers.