Continental drift — Science definition
Alfred Wegener's idea that continents were once joined together and have since slowly moved to their current positions.
Where it is taught
- Evidence for Continental Drift — Earth’s Interior & Plate Tectonics, Earth & Space Science, Grade 9
In use
That idea — continents wandering across the globe over vast stretches of time — became known as continental drift.
Evidence for Continental Drift
Questions using continental drift
Problem 1
- Isaac Newton
- Alfred Wegener
- Charles Darwin
- Albert Einstein
Answer and explanation
Alfred Wegener
Alfred Wegener proposed continental drift in 1912, based on evidence like matching coastlines and fossils.
Problem 2
- Matching fossils of the same species on continents now separated by oceans
- Modern GPS measurements of plate motion
- Satellite photographs of Earth
- Identical languages spoken on separated continents
Answer and explanation
Matching fossils of the same species on continents now separated by oceans
GPS and satellites didn't exist in 1912 — Wegener relied on evidence like matching fossils, rock layers, coastlines, and climate clues.
Problem 3
Answer and explanation
Wegener could not explain a physical mechanism for how huge, solid continents could move or plow through solid ocean floor, so most scientists didn't accept the idea until seafloor spreading was discovered in the 1960s.
Problem 4
- The invention of the seismograph
- Seafloor spreading and paleomagnetic stripes on the ocean floor
- The discovery of Mesosaurus fossils
- Wegener's original 1912 publication
Answer and explanation
Seafloor spreading and paleomagnetic stripes on the ocean floor
Seafloor spreading, confirmed by symmetric paleomagnetic stripes recorded in ocean-floor rock, finally explained how continents could move — giving plate tectonics its mechanism.