Applications and challenges of urban seismology - learnings from Singapore

Urban seismology has emerged as a distinct field for understanding the close interactions between human activities and the near-surface environment, particularly in densely populated regions. This presentation shares research experiences and insights from Singapore, a highly urbanized and dynamic setting. We examine case studies demonstrating the versatility of urban seismic methods in addressing engineering, environmental, and geophysical questions. These include using ambient noise monitoring for mapping bedrock interfaces, mitigating construction risks during tunneling, characterizing reclaimed land, and quantifying urban activities. By leveraging a combination of nodal seismometers and distributed acoustic sensing (DAS), our work has provided high-resolution subsurface models and continuous monitoring capabilities tailored to urban needs.

However, unique challenges arise in urban environments, including complex and temporally varying noise sources, limited sensor deployment options, and non-linear interactions between seismic waves and infrastructure. These issues are further compounded by the need to adapt conventional active and interferometric seismic workflows to account for heterogeneous urban conditions and to achieve meaningful resolutions for shallow subsurface features.

Our findings from Singapore underscore the potential of urban seismology to inform city planning, hazard mitigation, and sustainable infrastructure development. At the same time, they emphasize the necessity of developing innovative techniques and data processing strategies to overcome the complexities of urban noise and constrained observational settings. These learnings provide a foundation for extending urban seismology applications to other metropolitan regions worldwide.