West Eucla Basin (Seemore, Loongana), WA, 1983. (P490), 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 West Eucla Basin (Seemore, Loongana), WA, 1983. survey were acquired in 1983 by the WA Government, and consisted of 24580 line-kilometres of data at 1500m 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.

总磁场强度（Total Magnetic Intensity，TMI）数据用于测量地壳内造岩矿物成分差异引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常基准）与负异常（磁场强度低于正常基准），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于地下岩石。经处理得到的数据集可通过地质解译揭示地下地质结构。经处理的数据由GA的地球物理学家进行质量核验，以确保GA发布的最终数据符合使用要求。本次测线数据源自西澳大利亚州（WA）西埃克拉盆地（西莫尔Seemore、隆加纳Loongana区域）1983年的勘测项目，由西澳州政府于1983年采集完成，总测线长度达24580线公里，测线间距为1500米，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——全澳航空物探调查（Australia-wide Airborne Geophysical Survey，AWAGS）航空磁测数据——对本次勘测数据的基准水平进行校正。本次勘测数据实质上已根据AWAGS数据完成平差处理。