Total Magnetic Intensity HSI Image - 2019

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. This image is a combined Hue, Saturation, Intensity (HSI) color image of the TMI grid of the Australian region (Magmap 2019), with a grid cell size of 0.0008333 degrees (approximately 80m). This image only includes airborne-derived TMI data for onshore and near-offshore continental areas. The image shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The image can also be used to locate structural features such as dykes.

总磁强度（Total Magnetic Intensity, TMI）数据用于测量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（磁场强度高于正常值）与负异常（磁场强度低于正常值），其分类取决于岩石的磁化率。该数据集通过标准流程处理，以确保记录的响应仅来自地下岩石。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发布的最终数据符合使用需求。本图像为澳大利亚区域2019年磁图（Magmap 2019）的TMI网格数据的色调-饱和度-亮度（Hue, Saturation, Intensity, HSI）合成彩色图像，网格单元尺寸为0.0008333度（约80米）。该图像仅涵盖陆上及近岸陆地区域的航空探测TMI数据，呈现了具有不同磁化率的地下地质体的磁响应特征，同时可用于定位岩脉等构造特征。