How strong is the memory of the geomagnetic field? A critical appraisal of reversal asymmetry in precambrian rocks of Scotland

地球磁场的极性颠倒了，因此在颠倒之后，磁罗盘指向了相反的地理方向。这种情况在整个地质时期反复发生。一般来说，磁场的反转是反平行的，反转前后的磁化方向彼此成180度。然而，现在有几个例子表明，在岩石中记录的磁化方向表明，一系列的反转可能不是反平行的。这些观测结果可能是几次磁化事件的产物，在这种情况下，方向反映了采样地点地质历史的不同部分，而不是磁场的异常行为。该项目旨在测试古代磁化是否记录了这种不寻常的行为。与许多其他自然系统一样，非典型行为（如疾病）可以像正常状态一样提供信息。因此，这些结果可能会使我们对地球磁场的行为和演变有更深入的了解。

The Earth's magnetic field reverses its polarity such that after a reversal magnetic compasses point in the opposite geographical direction. This has occurred repeatedly throughout geological time. In general, reversals of the field are anti-parallel and the directions of magnetisation before and after a reversal lie at 180 degrees to each other. However, there are now several cases where the directions of magnetisation recorded in rocks indicate that a series of reversal may not have been anti-parallel. These observations might be the products of several magnetisation events and in these circumstances the directions reflect different parts of the geological history of the sampling site and not unusual behaviour of the field. This project is designed to test if ancient magnetisations have recorded such unusual behaviour. As with many other natural systems atypical behaviour (e.g. illness) can be as informative as the normal state. Thus, these results may lead to a greater understanding of how the Earth's field behaves and has evolved.