Flinders Island, Tasmania, 2007 (P1142), 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 Flinders Island, Tasmania, 2007 survey were acquired in 2007 by the TAS Government, and consisted of 18426 line-kilometres of data at 200m line spacing and 90m 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，简称TMI）数据用于量化地壳中成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（磁场强度高于正常背景场）与负异常（磁场强度低于正常背景场），其类型取决于岩石的磁化率。该数据通过标准处理流程开展预处理，以确保记录的磁场响应仅源自地下岩石。经处理得到的数据集可通过地质解译揭示地下地质结构。预处理后的数据会由GA的地球物理学家开展质量核查，以确保GA发布的最终数据满足实际使用需求。本次2007年塔斯马尼亚州（Tasmania，简称TAS）弗林德斯岛航磁测量的测线数据集，由塔斯马尼亚州政府于2007年采集完成，总测线长度达18426测线公里，测线间距为200米，飞行离地高度为90米。为压制数据中的长波长干扰，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，简称AWAGS）航空磁测数据——对本次测量数据的基准场进行校正。本次测量数据已基本校准至AWAGS基准体系。