DIPOLE AND NONDIPOLE FIELDS OF THE GEOMAGNETIC FIELD ON THE BASIS OF PALAEOINTENSITIES OF THE BRUNHES VOLCANIC ROCKS.

第一年研制了实验仪器，并用于测试样品的测量。交变磁场消磁器具有120 mT的最大输出，具有恒定的增加和减少磁场的速率。该恒定性为100 mT/60 sec，因为较高的速率往往导致较小的ARM。ARM与比较的NRM或TRM并行采集。这种ARM可以针对各向异性效应校正NRM或TRM强度。最高温度加热时间为10 min。20分钟。分别在第一次和第二次加热中。样品采集自日本的戴森火山、秘鲁的安第斯火山区和中国的大同单成火山。它们都形成于布鲁内时代。Shaw方法的双重加热导致32个样品中有13个样品成功。根据实测的古地震强度和倾角计算得到的垂直地震波，在以往的研究中，垂直地震波在平均垂直地震波周围呈分裂分布。这意味着地球发电机强度的分布可能比古地磁学家之前提出的更复杂。利用Matuyama-Brunhes转换的沉积记录的方向研究了非偶极/偶极场的相对强度变化。这些记录是从日本房总海洋沉积物中获得的。谱分析表明，在转捩场中，短周期变化是显著的，可能在10^2年的量级。

The experimental instruments were developed and used in the measurents of the test samples in the first year. The alternating field demagnetiser has a 120mT maximum output with a constant rate of increasing and decreasing fields. This constancy is of 100mT/60sec because the higher rate tends to result in a smaller ARM.The ARM is acquired in parallel to the NRM or TRM which is compared. Such an ARM can correct the NRM or TRM intensity for the anisotropy effects. The heating time at the top temperature is 10min. and 20min. in the first and the second heating, respectively. The samples were collected from Daisen Volcano (Japan), Andean volcanic region (Peru), and Datong monogenetic volcanoes (China). All of them were formed in the Brunhes epoch. Double heating of the Shaw method results in the success of 13 samples out of 32. The VDMs, calculated from the measured palaeointensities and the inclinations, show the splitted distribution around the mean VDMs in the previous reports. This implies the geodynamo intensities may have more complicated distribution than those previously suggested by the palaeomagnetists. The relative intensity change in the nondipople/dipole fields was investigated using the direcions of the sedimentary records of the Matuyama-Brunhes transition. The records were obtained from the Boso marine sediments in Japan. The spectral analyzes suggest that the short-period variations, probably of the order of 10^2 years, are remarkable in the transition field.