North Atlantic palaeointensity stack since 75ka (NAPIS–75) and the duration of the Laschamp event
North Atlantic palaeointensity stack since 75ka (NAPIS–75) and the duration of the Laschamp event
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DOI：
10.1098/rsta.2000.0571
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发表时间：
2000-03
期刊：
影响因子：
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通讯作者：
Carlo La j;C. Kissel;A. Mazaud;J. Channell;J. Beer
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文献类型：
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作者：
Carlo La j;C. Kissel;A. Mazaud;J. Channell;J. Beer
来自北大西洋的6个相对古强度记录被叠加在一起，创造了最近75KYR(Napis-75)的新记录。这些记录中有五个以前在千禧年尺度上进行了关联，并被放在GISP2年龄尺度上，第六个记录使用磁化率与其他记录联系在一起。从75ka开始，磁场强度表现出一些振荡，第一个最小值约为65ka，然后逐渐增加，以约48ka为中心，达到一个宽泛的最大值。然后在40ka处有一个明显的低点，对应于拉尚事件的方向性异常。另一个强度低，观察到约34ka，在年龄上对应于莫诺湖事件。在经历了33ka的高点和30ka和24ka的两个低点后，场强似乎慢慢增加到研究区间的上限。在10-20KYR区间内，各个记录之间存在一些差异，细微尺度的细节并不总是得到解决。另一方面，在20-75KYR区间内，分辨率良好的千禧年尺度特征与更广泛的趋势叠加在一起。拉尚事件被定向记录在五个核心中，其持续时间似乎约为1500年，这与最近关于地磁漂移起源的说法一致。
Six relative palaeointensity records from the north Atlantic Ocean were stacked together to produce a new record for the last 75 kyr (NAPIS–75). Five of these records have been previously correlated at millennial scale and placed on the GISP2 age scale, the sixth record was tied to the others using magnetic susceptibility. From 75 ka the field strength exhibits some oscillations, with a first minimum ca.65 ka, followed by a progressive increase to a broad maximum centred at ca.48 ka. There is then a well–marked low at 40 ka, corresponding to the directional anomaly of the Laschamp event. Another intensity low, observed at ca.34 ka, corresponds in age to the Mono Lake event. After a high at 33 ka and two lows at 30 and 24 ka with a broad maximum between, the field strength seems to slowly increase to the upper limit of the studied interval. In the 10–20 kyr interval some differences exist between individual records, and fine–scale details are not always resolved. In the 20–75 kyr interval, on the other hand, well–resolved millennial–scale features are superimposed to the broader trends. The duration of the Laschamp event, which is recorded directionally in five cores, appears to be about 1500 years, consistent with a recent suggestion on the origin of geomagnetic excursions.