EARTH × TECHNOLOGY
The Sea Floor Is a Conveyor
1963 to 1968 CE
Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan
The sea floor records the reversals of the Earth's magnetic field as stripes of alternating polarity, and the stripes on either side of a mid-ocean ridge mirror each other. There is only one way to get that pattern: rock is being made at the ridge and carried away in both directions. Continental drift had been proposed fifty years earlier and rejected for want of a mechanism. Here it was, printed on the ocean floor.
Why it matters
It turned geology from a collection of regional explanations into one theory, and it is why this timeline can speak of supercontinents assembling and breaking at all. Every date on the earth layer here assumes it.
Dating & uncertainty
Continental drift was proposed in 1912 and rejected for half a century because nothing could be found to move the continents. The magnetic stripes of the sea floor, symmetrical about the ridges, supplied the missing mechanism in 1963, and the full theory of plates followed within five years.
Sources
- Vine & Matthews (1963), Nature · Magnetic anomalies over oceanic ridges
- Wilson (1965), Nature · A new class of faults and their bearing on continental drift
- Merdith et al. (2021), Earth-Science Reviews · Extending full-plate tectonic models into deep time
Earth history as one day
23:59:59.99881.2 ms before midnight
if Earth’s 4.54 billion years were compressed into a single day
See it on the timeline