Southern Cross, WA, 1956 (P161), magnetic line data, AWAGS levelled

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Southern Cross, WA, 1956 survey were acquired in 1956 by the WA Government, and consisted of 11000 line-kilometres of data at 1600m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.

总磁强度（Total Magnetic Intensity, TMI）数据用于表征地壳内造岩矿物成分差异所引发的地球磁场强度变化。磁异常可依据岩石磁化率的差异分为正异常（磁场强度高于正常背景场）与负异常（磁场强度低于正常背景场）。该数据集通过标准化流程开展处理，以确保记录的响应仅源自地下岩石。经处理后得到的数据集可通过解译揭示地下地质构造。经处理的数据会由GA地球物理学家进行质量核验，以保障GA发布的最终数据符合使用需求。本次1956年南十字（Southern Cross）测线数据集采集于西澳大利亚州（Western Australia, WA），由西澳大利亚州政府于1956年完成获取，测线总长度达11000线千米，测线间距为1600米，飞行地形离地高度为150米。为约束数据中的长波长成分，研究人员采用独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次测线数据的基准水平进行校正。本次测线数据实质上已基于AWAGS完成平差处理。