Question

4. What evidence is there to suggest that tectonic plates move?

Answer 1

Between 3.5 and 3.2 billion years ago the Earth's interior began to run low on heat generating radioactive elements, the mantle cooled down and there were fewer hot magma plumes. Stable convection cells formed in the mantle and started driving plate movements, and subduction, and plate tectonics began to shape the Earth's surface.

Answer 2

1. Location of mountains and fossils

The ancient mountain ranges (many now eroded to their cores) and the location of rock types and fossils all match up. Earthquakes and Volcanoes, If we map the location of all the earthquakes recorded over time, almost all of them occur along what we recognize as plate boundaries.

2. The Earth’s magnetic = field flips every few hundred thousand years, and the stripes on the ocean floor show a record of those changes. By estimating when the flips occurred and pairing that with the distance the strips have moved from the spreading zone, scientists can estimate how fast the continents are moving.

3. Direct Measurement = Modern technology gives us a range of ways to directly measure the movement of tectonic plates. These methods are based around the idea of measuring distance between two points on Earth by using some intermediary transmitter in space. For example, SLR (Satellite Laser Ranging) uses two lasers on Earth, each of which fires a laser to a satellite orbiting the planet.