How does the concept of sea -floor spreading help support the idea that continents drift (thereby supporting Wegener’s theory )? As magna is thrust up and hardens forming new crossed, the ocean for on both sides of the mid ocean ridge move outward carrying the continents along with them.
How does seafloor spreading support the hypothesis of continental drift?
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere . ... At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.
What is the hypothesis of seafloor spreading?
sea-floor spreading — a hypothesis, proposed in the early 1960s, that new ocean floor is created where two plates move away from one another at mid-ocean ridges.
What is the major difference between the continental drift and seafloor spreading hypothesis?
Supporters of continental drift originally theorized that the continents moved (drifted) through unmoving oceans . Seafloor spreading proves that the ocean itself is a site of tectonic activity. Seafloor spreading is just one part of plate tectonics. Subduction is another.
What are the three types of seafloor spreading?
There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide, divergent , where plates separate, and transform motion, where plates simply slide past each other.
What are the similarities and differences of plate tectonics and continental drift?
The main difference between plate tectonics and continental drift is that plate tectonics describes the features and movement of Earth’s surface in the present and in the past whereas continental drift describes the drifting of Earth’s continents on the ocean bed.
What is the difference between Pangea and continental drift?
Continental drift describes one of the earliest ways geologists thought continents moved over time. ... He called this movement continental drift. Pangaea. Wegener was convinced that all of Earth’s continents were once part of an enormous, single landmass called Pangaea .
What evidence did Alfred use?
He used fossil evidence , such as that of tropical plants found on the Arctic island of Spitzbergen. He found large-scale geographic features that matched, like the Appalachian Mountains in the United States and the Scottish Highlands, as well as rock strata in South Africa that matched those in Brazil.
What is the first step of seafloor spreading?
1. A long crack in the oceanic crust forms at a mid ocean ridge . 2. Molten material rises and erupts along the ridge.
What are two pieces of evidence for seafloor spreading?
Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading- evidence from molten material, magnetic stripes, and drilling samples . This evidence also led sci- entists to look again at Wegener’s theory of continental drift.
What are the features of seafloor?
Features of the ocean include the continental shelf, slope, and rise . The ocean floor is called the abyssal plain
What are the 4 evidence of continental drift?
They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils .
What is the relationship of continental drift and plate tectonics?
The theory of continental drift suggests that all the land masses on earth were once part of one supercontinent . Plate tectonics is the ability to measure the movement of land masses.
What are the 3 theories of plate tectonics?
The three types of plate boundaries are divergent, convergent, and transform . They are described in the following three concepts. Most geological activity takes place at plate boundaries.
What are 5 pieces of evidence that support continental drift?
The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones .
What are 6 pieces of evidence that support continental drift?
- Fossils.
- Continents fit like Puzzle Pieces. Matching fossils preserved in rocks of the same age but found on different continents. Ex. ...
- Matching Rocks. Puzzle – like fit of continental shelves. Ex. ...
- Mountain Ranges.
- Glacier Striations.
- Coal Beds.
