Esperance - Malcolm, WA, 2008 (P1189), 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 Esperance - Malcolm, WA, 2008 survey were acquired in 2008 by the WA Government, and consisted of 84609 line-kilometres of data at 400m line spacing and 60m 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）数据用于表征由地壳中成岩矿物含量差异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）与负异常（磁场强度低于正常背景），其类型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由地下岩石引起。处理所得数据集可通过解译揭示地下地质构造。经处理的数据由GA地球物理学家开展质量核验，以确保GA发布的最终数据满足使用需求。这套测线数据集源自2008年开展的西澳大利亚州（Western Australia, WA）埃斯佩兰斯-马尔科姆（Esperance - Malcolm）调查项目，由西澳大利亚州政府于2008年采集，总测线长度达84609公里，测线间距为400米，飞行离地高度为60米。为压制数据中的长波长信号，研究人员采用独立数据集——全澳大利亚航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）航空磁测数据——对本次调查数据的基准水平进行校正。本次调查数据实质上已基于AWAGS数据集完成平差处理。