Presentation is loading. Please wait.

Presentation is loading. Please wait.

Topography of the Ocean Floor

Similar presentations


Presentation on theme: "Topography of the Ocean Floor"— Presentation transcript:

1 Topography of the Ocean Floor

2 Parts of an ocean wave The winds cause waves on the surface of the ocean (and on lakes). The wind transfers some of its energy to the water, through friction between the air molecules and the water molecules. Stronger winds (like storm surges) cause larger waves.

3 Guyots and Sea Mounts A guyot /giɘʊ/, also known as a tablemount, is a flat-topped seamount. Guyots are most commonly found in the Pacific Ocean

4 Location and formation
There are thought to be an estimated 50,000 seamounts in the Pacific basin. The Emperor Seamounts are an excellent example of an entire volcanic chain undergoing this process. Guyots show evidence of having been above the surface with gradual subsidence, the sinking down of land resulting from natural shifts, through stages from fringed reefed mountain, coral atoll, and finally a flat topped submerged mountain. Their flatness is due to erosion by waves, winds, and atmospheric processes.

5 Mid Ocean Ridge A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, typically having a valley known as a rift running along its spine, formed by plate tectonics

6 The mid-ocean ridges of the world are connected and form a single global mid-oceanic ridge system that is part of every ocean, making the mid-oceanic ridge system the longest mountain range in the world. The continuous mountain range is 65,000 km (40,400 mi) long and the total length of the system is 80,000 km (49,700 mi)[

7 Sea floor Spreading The uplifted sea floor results from convection currents which rise in the mantle as magma at a linear weakness in the oceanic crust, and emerge as lava, creating new crust upon cooling. divergent plate boundary.

8 Continental Shelf Combined with the sunlight available in shallow waters, the continental shelves teem with life Name a few

9 Continental Shelf Food Web

10 The global continental shelf, highlighted in cyan

11 Continental Shelf The continental shelf is the extended perimeter of each continent and associated coastal plain, and was part of the continent during the glacial periods, but is undersea during interglacial periods s (times of freezing and melting) uch as the current epoch by relatively shallow seas (known as shelf seas) and gulfs. The largest shelf – the Siberian Shelf in the Arctic Ocean – stretches to 1500 kilometers (930 miles) in width. Some continients do not have a continental shelf, but rather directly to the slope.

12 The continental slope connects the continental shelf and the oceanic crust. It begins at the continental shelf break, or where the bottom sharply drops off into a steep slope. It usually begins at 430 feet (130 meters) depth and can be up to 20 km wide. The continental slope, which is still considered part of the continent, together with the continental shelf is called the continental margin.

13 Continental Slope The continental slope is a submarine geological feature which connects the continental shelf to the abyssal plain, beginning at a depth of around 460 feet (140 meters). Together, the continental slope and the continental shelf are often referred to as the “continental margin,” in a reference to the fact that the combined features are found at the margins of the Earth's continent. The continental slope also happens to mark the boundary between the part of the world's ocean scientists are familiar with and the mysteries of the deep sea.

14 Life in the Continental Slope
As the continental slope plunges into the deeper parts of the ocean, conditions quickly change. The water becomes much colder and more sluggish. It is also totally devoid of life, and oxygen levels decline as well. As a result, the ocean life along the continental slope is markedly different than that found along the continental shelf, as it must be much more tolerant of extreme conditions. The deeper these animals live, the more intense the pressure gets; organisms from shallower depths, including humans, would literally start to implode from the pressure

15

16 Frilled Shark Fang tooth fish

17 FREAKY CRITTERS from the deep
Frilled Shark Fang tooth fish

18 Abyssal Plain

19 Abyssal Plain Abyssal plains are flat or very gently sloping areas of the deep ocean basin floor. They are among the Earth's flattest and smoothest regions and the least explored. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. The remainder of the sediment comprises chiefly dust (clay particles) blown out to sea from land, and the remains of small marine plants and animals (the plankton), which sink from the upper layer of the ocean, known as Pelagic sediments.

20 Deep Sea Trench Trenches define one of the most important natural boundaries on the Earth’s solid surface, that between two lithospheric plates. There are three types of lithospheric plate boundaries: divergent (where lithosphere and oceanic crust is created at mid-ocean ridges), convergent (where one lithospheric plate sinks beneath another and returns to the mantle), and transform (where two lithospheric plates slide past each other).

21 Length North to South: 11,000 miles Deepest point: Mariana Trench at 35,797 feet Meaning of 'Pacific': 'Peaceful' Average Depth: 14,000 feet Islands in the Pacific: About 25,000 Temperature: 32 °F to 84 °F

22

23


Download ppt "Topography of the Ocean Floor"

Similar presentations


Ads by Google