Strathblane and Catamaran, Tas, 1982 (P835), 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 Strathblane and Catamaran, Tas, 1982 survey were acquired in 1982 by the TAS Government, and consisted of 1511 line-kilometres of data at 500m line spacing and 135m 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）数据用于量化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）两类，具体取决于岩石的磁化率。该数据通过标准流程进行处理，以确保所记录的响应仅源于地下岩石。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地球物理学家开展质量核查，以确保GA发布的最终数据符合使用要求。本次1982年勘测的航线数据集采集自塔斯马尼亚州斯特拉斯布兰（Strathblane）与卡塔马兰（Catamaran）区域，由塔斯马尼亚州政府于1982年采集，数据总长1511线公里，航线间距为500米，地形离地高度为135米。为抑制数据中的长波长成分，研究人员采用澳大利亚全国航空地球物理勘测（Australia-wide Airborne Geophysical Survey, AWAGS）的航空磁测数据作为独立数据集，对本次勘测数据的基准水平进行校正。本次勘测数据已基本校准至AWAGS基准体系。