Mt Elizabeth magnetic grid

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 Mt Elizabeth magnetic grid has a cell size of 0.00083 degrees (approximately 91m). The units are in nanoTesla (or nT). The data used to produce this grid was acquired in 1993 by the WA Government, and consisted of 50696 line-kilometres of data at 400m line spacing and 60m terrain clearance.

总磁场强度（Total Magnetic Intensity，缩写TMI）数据用于衡量地壳中成岩矿物含量差异所导致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），其分类依据为岩石的磁化率。该数据已通过标准流程进行处理，以确保记录的响应仅源自地下岩石。处理后得到的数据集可通过解译工作揭示地下地质构造。经处理的数据已由GA的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要求。本次伊丽莎白山（Mt Elizabeth）磁网格数据的单元尺寸为0.00083度（约合91米），数据单位为纳特斯拉（nanoTesla，缩写nT）。本网格所用数据由西澳大利亚州政府（WA）于1993年采集，总测线长度达50696线公里，测线间距为400米，地形离地航高为60米。