Mangana-Alberton, NE Tas, 1989 (P559), 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 Mangana-Alberton, NE Tas, 1989 survey were acquired in 1989 by the TAS Government, and consisted of 2755 line-kilometres of data at 500m line spacing and 243m 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.

总磁场强度（Total Magnetic Intensity, TMI）数据可表征由地壳内造岩矿物成分差异所引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常值）与负异常（磁场强度低于正常值），具体取决于岩石的磁化率。该数据集通过标准流程进行处理，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结构。经GA地球物理学家开展质量检查，确保GA发布的最终数据集符合使用要求。本次涉及的测线数据集源自1989年塔斯马尼亚州政府开展的塔斯马尼亚东北部曼加纳-奥伯顿（Mangana-Alberton）航空磁测，共获取2755线千米的测线数据，测线间距为500米，飞行离地高度为243米。为压制数据中的长波长信号，研究人员采用独立数据集——澳大利亚全域航空地球物理调查（Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次测线数据的基准面进行校正。本次测线数据实质上已基于AWAGS数据完成平差处理。