WA Array: A High-Resolution Passive-Source Seismic Survey to Image the West Australian Lithosphere

Abstract

In late 2022, the Geological Survey of Western Australia commenced the deployment of a new 10 yr seismic imaging array, Western Australia (WA) array. With the geological history of WA stretching from the Archean to the present, WA array is a natural platform for the study of lithospheric structures pre- and post-establishment of the modern plate tectonics. Despite being a stable craton, certain parts of WA have high seismic activity. This large-scale initiative will map areas of seismic risk for industrial infrastructure and future land use planning and investigate its relationship with the crustal and lithospheric mantle structures using a variety of methods. An economic objective is to identify prospective regions for mineral and energy exploration, especially in areas that have previously been underexplored or for new commodities such as hydrogen. The WA array imaging program will cover the whole State, more than 2.5 million square kilometers, using a grid station spacing of 40 km. The data acquisition is predicted to take 10 yr during which time 1600 stations will be deployed. It is anticipated that this will become one of the largest passive seismic investigations yet instigated. Here, we present and discuss the array design, current deployment status, initial modeling results, expected model updates, and potential implications for the program.