Submarine

Chemistry

Merge (version control)

Geophysics

Instrumentation (computer programming)

Engineering

Remote sensing

Telecommunications

Geology

Aerospace engineering

Organic chemistry

Optical fiber cable

Submarine pipeline

Microseism

Operating system

Phytoplankton

Survivability

Computer science

SeaWiFS

Nutrient

Seafloor spreading

Information retrieval

Oceanography

Seismology

Optical fiber

Science

Seafloor geophysical instrumentation is challenging to deploy and maintain but critical for studying submarine earthquakes and Earth's interior. Emerging fiber-optic sensing technologies that can leverage submarine telecommunication cables present an opportunity to fill the data gap. We successfully sensed seismic and water waves over a 10,000-kilometer-long submarine cable connecting Los Angeles, California, and Valparaiso, Chile, by monitoring the polarization of regular optical telecommunication channels. We detected multiple moderate-to-large earthquakes along the cable in the 10-millihertz to 5-hertz band. We also recorded pressure signals from ocean swells in the primary microseism band, implying the potential for tsunami sensing. Our method, because it does not require specialized equipment, laser sources, or dedicated fibers, is highly scalable for converting global submarine cables into continuous real-time earthquake and tsunami observatories.

Optical polarization–based seismic and water wave sensing on transoceanic cables