Marine Science. Chapter 2 – The Sea Floor. FOCUS QUESTIONS. What are the major physical features of the Earth’s surface? What explanation have scientists developed for the existence and distribution of these features? How do these features affect the Earth’s oceans?. Our Fledgling Planet.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Chapter 2 – The Sea Floor
Materials have settled in the planet according to their density.
d = m/V
Lithosphere (crust – very thin)
Asthenosphere (upper mantle – fluid)
Mesosphere (mid to lower mantle – solid but very hot)
Core (mixtures of iron – inner is solid, outer is molten)
… than Oceanic crust.
See Table 2.2 on page 24
Plate tectonics – the study of the processes by which the lithosphere moves laterally across the asthenosphere.
There are areas where plates spread apart…
…and areas where plates collide.
Mid-ocean Ridges/ Rifts
Subduction zones/ Trenches
India Collision Animation
Above: Mid-Atlantic Ridge Left: Iceland –showing ridge
Above: The Glomar Challenger was the first research vessel specifically designed in the late 1960s for the purpose of drilling into and taking core samples from the deep ocean floor.
Geologists noted the similarities between the fossils and sediment deposits found on opposite sides of the Atlantic Ocean.
Although this model has been contested, it describes a stationary magma source over which plates slide.
A. Continental shelf – The shallow gently sloping section of the continental margin that extends from the shore to the point where the slope gets steeper.
B. Shelf break – The section of the continental shelf where the slope abruptly becomes steeper, usually at a depth of 120 to 200 m (400 to 600 ft).
C. Continental Slope – The steeper, seaward section of the continental margin.
D. Continental Rise –The gently sloping area at the base of the continental slope.