GSWA Broome North Canning 1 ppm Thorium Grid Geodetic

The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected 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 radiometric thorium grid has a cell size of 0.00083 degrees (approximately 90m) and shows thorium element concentration of the Broome, WA, 2009 (North Canning 1) in units of parts per million (or ppm). The data used to produce this grid was acquired in 2009 by the WA Government, and consisted of 76474 line-kilometres of data at 400m line spacing and 60m terrain clearance.

放射性测量法（radiometric method，即伽马能谱法（gamma-ray spectrometric method））通过探测地表附近的伽马射线自然变化，来反映钾（K）、铀（U）与钍（Th）的天然放射性衰变所产生的信号。采集所得数据将通过标准流程进行处理，以确保记录的信号仅源于地下岩石的放射性衰变。经处理后得到的数据集可通过解译，用以揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量核查，以确保GA发布的最终数据符合使用需求。
本次放射性钍格网数据的单元格尺寸为0.00083度（约合90米），展示了2009年西澳大利亚州（Western Australia，WA）布鲁姆（Broome）区域（北坎宁1号（North Canning 1））的钍元素浓度分布，浓度单位为百万分率（parts per million，ppm）。用于生成该格网的数据由西澳大利亚州政府于2009年采集，涵盖76474线公里的测线数据，测线间距为400米，飞行离地高度为60米。