Only 0.001% of Earth’s Deep Seafloor Visually Explored, Finds New Study

A landmark study published in Science Advances reveals the staggering gap in visual exploration of the Earth’s deep ocean — defined as areas 200 meters or more below sea level. Despite covering two-thirds of Earth’s surface, this ecosystem remains largely uncharted.

Key Highlights:

Importance of Visual Imaging in Deep Ocean Research:

• Essential for contextualizing biological and geological sample collection.
• Critical for calibrating remote-sensing data.
• Helps understand marine biodiversity and geological formations.

Scope of the Study

• Conducted by U.S.-based researchers using data from:
• 43,681 visual dive records
• 34 institutions across 14 countries
• 120 Exclusive Economic Zones (EEZs) and high seas
• Data sources: Institutional archives, public databases, and published scientific literature.

Methodology and Estimates

• Two analytical approaches:
• Area-based estimation: Imaged area between 1,259 km² to 2,130 km²
• Duration-speed method: Estimated 3,823 km² covered in 66 years
• Conclusion: Only 0.001% of deep seafloor has been visually imaged.

Geographical Disparity and Bias

• 97% of dives from only five countries:
• United States, Japan, New Zealand, France, Germany
• No dive records from Africa and most of Latin America
• Topographic bias:
• Overrepresented: Canyons, escarpments
• Underrepresented: Abyssal plains (which dominate ocean floor)

Implications and Challenges

• Current visual data equals only half the area of Goa.
• Inferences on deep-sea ecosystems drawn from an extremely limited sample.
• If 1,000 imaging platforms operate at present speed (~3 km²/year/platform), it would still take 100,000 years to image the entire deep seafloor once.

TH