AusArray temporary passive seismic station deployment, servicing and retrieval: Geoscience Australia standard operating procedures - Revised Edition 2025

The Australian Passive Seismic Array Project (AusArray) program was developed from a long history of passive seismic imaging in Australia involving many contributors. Building on this history, the Australian Government and academia have united around AusArray. The objective is a standardised and quality controlled national passive seismic data coverage and an updatable national seismic velocity model framework that can be used as a background for higher-resolution studies. This document details the field activities and equipment preparation for temporary passive seismic station deployment, service and retrieval. Equipment cleaning and testing and database details are also described. The standard operating procedures applied during these activities were established during the deployment of two temporary passive seismograph arrays from 2016 to 2020 under the Australian Government’s Exploring for the Future (EFTF) program. These arrays consisted of 120–130 stations deployed in the Northern Territory and Queensland for over a year in a grid pattern with a lateral spacing of half a degree (~55 km). The temporary passive seismograph stations comprised Nanometrics Trillium Compact 120S broadband seismic sensors connected to a Güralp minimus digitiser. Batteries charged by a solar panel powered both instruments. Each station in the array was serviced, i.e. repairs if required and interim data was retrieved, at least once during the deployment. From 2021 to 2024 the broadband seismic instruments were arranged in a grid pattern spaced 2-degrees or ~220 km apart across the entire continent to ensure a robust continental framework. Further deployments will continue under Geoscience Australia’s Resourcing Australia’s Prosperity initiative. Since publication in 2022 the original document was consistently updated with improvements developed from ongoing field operations to create this version completed in August 2025. Major updates include using equipment from the Australian National University (ANU), site testing performing waveform analytics during servicing, and making the sites more secure to prevent damage from animals. Field operations were improved with more details to make the procedures easier to follow and reduce equipment damage.