What is the evidence of seafloor spreading?

What is the evidence of seafloor spreading?

The theory of seafloor spreading states that new ocean crust is continually being formed, and that this crust is slowly carried away from its point of origin over a period of time. The study of the repeated reversal of the Earth’s magnetic poles over time has provided convincing evidence of seafloor spreading.

How does magnetic stripes support seafloor spreading?

When lava gets erupted at the mid-ocean ridge axis it cools and turns into hard rock. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges. These patterns of stripes provide the history of seafloor spreading.

Why are magnetic patterns found on the ocean floor puzzling?

Why were magnetic patterns found on the ocean floor puzzling? No rocks were magnetic. They did not show alternating bands of normal and reversed polarity.

What is magnetic striping on the seafloor?

What Is Magnetic Striping? Magnetic Striping is when the sea floor is spreading, and magma from the mantle is rising through the Earth’s crust. That magma then turns into new crust, forming the “Oceanic Crust”.

How does magnetic field affect seafloor spreading?

When the Earth’s magnetic field reverses, a new stripe, with the new polarity, begins. Such magnetic patterns led to recognition of the occurrence of sea-floor spreading, and they remain some of the strongest evidence for the theory of plate tectonics.

How are magnetic patterns found on the seafloor?

Data from magnetometers dragged behind ships looking for enemy submarines in WWII discovered amazing magnetic patterns on the seafloor. Rocks of normal and reversed polarity are found in stripes symmetrically about the mid-ocean ridge axis.

How is the evidence for seafloor spreading discovered?

Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading – evidence from molten material, magnetic stripes, and drilling samples. How was seafloor spreading discovered? This theory later became known as ‘ Sea Floor Spreading ‘. …

How are the ages of seafloor rocks determined?

The age of seafloor rocks increases from the ridge crest to rocks the farthest from the ridges. Still, the rocks of the ocean basins are much younger than most of the rocks of the continents. Describe the pattern the magnetic stripes make in the ocean floor.

Where do the stripes end on the seafloor?

Stripes end abruptly at the edges of continents, sometimes at a deep sea trench ( Figure below ). Magnetic polarity is normal at the ridge crest but reversed in symmetrical patterns away from the ridge center. This normal and reversed pattern continues across the seafloor.