Urban Sensing Using Existing Fiber-Optic Networks

TL;DR

This paper demonstrates how existing fiber-optic telecommunication networks can be repurposed as dense seismic sensors to accurately detect, localize, and analyze urban seismic sources and their temporal variations.

Contribution

It introduces a novel method of using fiber-optic networks as seismic arrays, enabling city-wide seismic source localization without deploying dedicated seismometers.

Findings

Successfully localized urban seismic sources in San Jose, CA.

Found strong correlation between seismic source power and urban features.

Demonstrated cost-effective urban seismic monitoring using existing infrastructure.

Abstract

The analysis of urban seismic signals offers valuable insights into urban environments and society. Yet, accurate detection and localization of seismic sources on a city-wide scale with conventional seismographic network is unavailable due to the prohibitive costs of ultra-dense seismic arrays required for imaging high-frequency anthropogenic sources. Here, we leverage existing fiber-optic networks as a distributed acoustic sensing system to accurately locate urban seismic sources and estimate how their intensity varies over time. By repurposing a 50-kilometer telecommunication fiber into an ultra-dense seismic array, we generate spatiotemporal maps of seismic source power (SSP) across San Jose, California. Our approach overcomes the proximity limitations of urban seismic sensing, enabling accurate localization of remote seismic sources generated by urban activities, such as traffic, construction, and school operations. We also show strong correlations between SSP values and environmental noise levels, as well as various persistent urban features, including land use patterns and demographics.