Anshul Shah

University of Washington, VISIONS’25

Distributed Acoustic Sensing (DAS) is revolutionizing environmental monitoring, offering a groundbreaking new way to observe and understand the oceans in ways that were once unimaginable. By transforming the vast depths of the sea into a transparent realm, DAS has been likened to the first-ever “telescope” for the oceans, revealing phenomena in real-time that were previously invisible to us.

At the heart of this technology is the ability to detect minute deformations in laser light that travels along fiber optic cables, allowing researchers to “sense” a wide variety of underwater events and activities. These include seismic events, tsunami waves, the songs of marine mammals, and even the faint hum of the Earth itself, generated by the constant motion of waves breaking along coasts around the world.

This short documentary explores how DAS works, why it holds the potential to transform our understanding of the deep sea, and its ability to capture real-time data over entire ocean basins using submarine fiber optic cables. The first community-driven experiments funded by the National Science Foundation, were conducted as part of the Ocean Observatories Initiative Regional Cabled Array located off the coast of Oregon. Over a 4-day period the system collected ~30 terabytes of data and imaged tens of thousands of whale calls! Through DAS, researchers have the ability to image ocean phenomena as never before.