Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity‐inclination correlation revisited
Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity‐inclination correlation revisited
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DOI：
10.1029/2008gl035373
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发表时间：
2008-10
影响因子：
5.2
通讯作者：
T. Yamazaki;T. Kanamatsu;Sakiko Mizuno;N. Hokanishi;E. Gaffar
中科院分区：
文献类型：
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作者：
T. Yamazaki;T. Kanamatsu;Sakiko Mizuno;N. Hokanishi;E. Gaffar
对赤道西太平洋西加罗林海盆新近获得的4个活塞岩心进行了古地磁研究，以探讨近40万年来古地磁强度和倾角的变化。以前在该地区使用巨型活塞岩心报告了倾斜强度相关性，但最近一次报告的年轻端的古地磁数据的质量。300 kyr，需要进行检查，因为巨型活塞芯的上部可能会受到过采样的扰动。年龄控制基于一个岩心的氧同位素比和其他岩心的相对古强度的岩心间对比。利用四个岩心构造了古地震强度和倾角叠加曲线。据证实，在104至105年的顺序上的变化发生在倾斜以及古强度。互相关分析表明，在大于25 kyr的时间段内，强度和倾角之间出现了显着的同相相关，古强度和倾角变化的功率谱在100 kyr的时间段内都有峰值。分辨率高于Sint-800叠加（Guyodo和Valet，1999）的区域古强度叠加应该对古强度辅助年代地层学有用。
A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination‐intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen‐isotope ratios for one core and inter‐core correlation using relative paleointensity for other cores. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that variations on the order of 104 to 105 years occur in inclination as well as paleointensity. A cross‐correlation analysis showed that significant in‐phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ∼100 kyr periods. The regional paleointensity stack with higher resolution than the Sint‐800 stack (Guyodo and Valet, 1999) should be useful for paleointensity‐assisted chronostratigraphy.