No Evidence for Milankovitch Cycle Influence on Abyssal Hills at Intermediate, Fast, and Superfast Spreading Rates
No Evidence for Milankovitch Cycle Influence on Abyssal Hills at Intermediate, Fast, and Superfast Spreading Rates
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DOI：
10.1029/2018gl079400
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发表时间：
2018-10-16
影响因子：
5.2
通讯作者：
Mueller, R. Dietmar
中科院分区：
文献类型：
--
作者：
Goff, John A.;Zahirovic, Sabin;Mueller, R. Dietmar
最近的一个假说认为，深海丘陵地形与米兰科维奇旋回所表示的海平面周期性有关，预测深海丘陵海拔与地壳年龄有关。我们测试这个预测堆叠（平均）测深作为年龄的函数，以提高年龄相关的信号，同时抑制随机（主要是故障）组件。叠加适用于中间、快速和超快速扩张海脊两侧的测深数据。在这些地区使用最近汇编的可靠的磁异常识别，与推断的时间不确定性类似的0.01百万年，产生了修订的数字地壳年龄模型。我们利用深海丘陵的统计特性来预测的变化的年龄叠加的零假设，即深海丘陵是随机的地壳年龄;年龄叠加的配置文件是显着不同的零，只有当它超过了这个预期的变化由一个很大的保证金。我们的研究结果不支持存在的Milankovitch驱动的信号在深海丘陵topology.Plain语言摘要最近的研究表明，深海丘陵，划线的海底功能所造成的断层和岩浆活动在大洋中脊扩张，与地球的气候周期。这一假说认为，伴随气候变化的海平面升降将调节深海压力，从而调节有助于深海山丘形成的岩浆产出。它还做出了一个重要的预测：作为地壳年龄的函数，各处的深海丘陵都将具有相干信号。在这里，我们通过“叠加”或平均深海丘陵水深作为年龄的函数来测试这一预测，这应该会抑制任何随机成分（例如，断层）并增强任何相干分量。然而，我们发现，没有统计上显着的年龄相关的信号，因此，没有证据表明，在这种分析的气候驱动的信号在深海丘陵。
A recent hypothesis contends that abyssal hill topography is linked to sea level periodicities expressed by Milankovitch cycles, predicting that abyssal hill elevation is correlated to crustal age. We test this prediction by stacking (averaging) bathymetry as a function of age to enhance age-dependent signal while suppressing random (primarily faulted) components. Stacking is applied to bathymetry data flanking intermediate, fast, and superfast spreading ridges. Revised digital crustal age models were generated in these regions using a recent compilation of reliable magnetic anomaly identifications, with inferred temporal uncertainty of similar to 0.01 my. We utilize statistical properties of abyssal hills to predict the variability of the age-stack under the null hypothesis that abyssal hills are random with respect to crustal age; the age-stacked profile is significantly different from zero only if it exceeds this expected variability by a large margin. Our results do not support the presence of Milankovitch-driven signals in abyssal hill topography.Plain Language Summary Recent studies suggest that abyssal hills, lineated seafloor features created by faulting and magmatism at mid-ocean spreading ridges, are linked to the Earth's climate cycles. This hypothesis contends that the rising and falling of sea level that accompanies climate change will modulate pressure at depth and thus the magmatic output that contributes to abyssal hill construction. It also makes an important prediction: Abyssal hills everywhere will have a coherent signal as a function of crustal age. Here we test this prediction through "stacking" or averaging abyssal hill bathymetry as a function of age, which should suppress any random component (e.g., faulting) and enhance any coherent component. We find, however, that there is no statistically significant age-dependent signal and therefore that there is no evidence in this analysis of a climate-driven signal in abyssal hills.