Isostatic Residual Gravity Anomaly Grid of Onshore Australia 2016

This grid is derived from gravity observations stored in the Australian National Gravity Database (ANGD) as at February 2016 as well as data from the 2013 New South Wales Riverina gravity survey. Out of the approximately 1.8 million gravity observations 1,371,998 gravity stations in the ANGD together with 19,558 stations from the Riverina survey were used to generate this image. The grid shows isostatic residual gravity anomalies over onshore continental Australia. The data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day.
The isostatic corrections were based on the assumption that topographic loads are compensated at depth by crustal roots following the Airy-Heiskanen isostatic principle. A crustal density of 2670 kg/m3 was used for the isostatic correction, with an assumed density contrast between the crust and mantle of 400 kg/m3. An initial average depth to Moho at sea level of 37 km was used in the calculation. The isostatic corrections were then applied to the Complete Bouguer Gravity Anomaly Grid of Onshore Australia 2016 to produce the Isostatic Residual Gravity Anomaly Grid of Onshore Australia 2016.

本重力格网数据源自2016年2月存储于澳大利亚国家重力数据库（Australian National Gravity Database, ANGD）中的重力观测资料，以及2013年新南威尔士州里弗赖纳（Riverina）重力调查获取的数据。本次格网生成共使用约180万条重力观测数据中的1,371,998条ANGD内重力测站数据，外加里弗赖纳调查的19,558条测站数据。该格网展示了澳大利亚陆域大陆的均衡剩余重力异常分布。本格网所用数据自20世纪40年代至今，由澳大利亚联邦、各州及领地政府、矿业与勘探行业、高校及科研机构采集获取。
本次均衡校正基于艾里-海斯卡宁（Airy-Heiskanen）均衡原理，即地形负载通过深部地壳根域实现补偿的假设。均衡校正采用地壳密度为2670 kg/m³，假定地壳与地幔间的密度差为400 kg/m³。计算过程中采用海平面处莫霍界面的初始平均深度为37 km。随后将该均衡校正应用于2016年澳大利亚陆域完全布格重力异常（Complete Bouguer Gravity Anomaly）格网，最终生成2016年澳大利亚陆域均衡剩余重力异常格网。