GSQ Mt Isa Southwest magnetic grid geodetic

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 GSQ Mt Isa Southwest magnetic grid geodetic has a cell size of 0.00083 degrees (approximately 88m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 2006 by the QLD Government, and consisted of 139836 line-kilometres of data at 400m line spacing and 80m terrain clearance.

总磁强度（Total Magnetic Intensity, TMI）数据用于表征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值）与负异常（磁场强度低于正常背景值），其极性取决于岩石的磁化率。该数据需经过标准化流程处理，以确保所记录的磁场响应仅源于地下岩石的影响。经处理得到的数据集可通过解译揭示地下地质构造特征。处理后的数据将由GA地球物理学家开展质量核查，以确保GA发布的最终数据满足使用需求。本次GSQ芒特艾萨西南磁测大地测量网格的单元尺寸为0.00083度（约88米），数据单位为纳特斯拉（nanoTesla, nT）。用于生成该网格的数据由昆士兰州政府（QLD Government）于2006年采集，总测线长度达139836线公里，测线间距为400米，采集时的地形离地高度为80米。