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Earth Science & Geology · Recorded milestone

Plate tectonics

Recorded year1962

Harry Hess uses sonar maps of ocean ridges to propose seafloor spreading, leading to plate tectonics by 1968.

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Built on

Radiometric datingRecorded · 1907enables
Active sonarRecorded · 1918enables
Echo-sounding seafloor surveyRecorded · 1925enables

Led to

Ocean drilling shipRecorded · 1968enables
GPS plate trackingRecorded · 1996enables
Earthquake early warningRecorded · 2007enables

Sources & evidence

Additional source

Dataset updated 2026-10-18. This individual record has not been separately re-reviewed.