This has happened many times throughout earth s history.
Sea floor spreading age of rocks.
The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century.
Sea floor spreading a theory thought up by harry hess in the late 1950s was drawn up in relation to the differing ages of rocks which make up oceanic crust ie the ocean floor.
How do the ages of the rocks on the ocean floor support the theory of seafloor spreading answers the ages of the rocks become older the farther the way they are the closer they are the younger it.
Every once in a while the currents in the liquid core which create the earth s magnetic field reverse themselves.
These age data also allow the rate of seafloor spreading to be determined and they show that rates vary from about 0 1 cm 0 04 inch per year to 17 cm 6 7 inches per year.
Hydrothermal vents are common at spreading centers.
Seafloor spreading is a geologic process where there is a gradual addition of new oceanic crust in the ocean floor through a volcanic activity while moving the older rocks away from the mid oceanic ridge.
Scientists can determine the age of the seafloor by examining the changing magnetic field of our planet.
Past 160 million years by seafloor spreading at the oceanic ridges and the continental lithosphere accumulated over the past 4 billion years.
It is called a geomagnetic reversal.
See plate tectonics the largest.
At spreading rates of about 15 cm 6 inches per year the entire crust beneath the pacific ocean about 15 000 km 9 300 miles wide could be produced in 100 million years.
Basalt the once molten rock that makes up most new oceanic crust is a fairly magnetic substance and scientists began using magnetometer s to measure the magnetism of the ocean floor in the 1950s.
In this series of 4 investigations they explain how the age of crustal rocks provides evidence of seafloor spreading.
Older rocks will be found farther away from the spreading zone while younger rocks will be found nearer to the spreading zone.
A history of ocean floor mapping and dating the ocean floor is a mysterious place that marine geologists and oceanographers have struggled to fully grasp.
At a spreading center basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.
The mid ocean ridge is where the seafloor spreading occurs in which tectonic plates large slabs of earth s lithosphere split apart from each other.
Students will model core sampling identify patterns in data on the age of the ocean floor use magnetic data to model seafloor spreading and explore the density of oceanic and continental crust.
