Topography Is the study of Earth's surface shape and features. Ocean topography is the study of the ocean floor and the features.

Earth’s Solid-Surface Topography

Topography of Earth’s Ocean Basins

Topography of Pacific Ocean Basin

SONAR

Sound Navigation and Ranging SONAR

C. Echo Sounding Shapes can be determined by measuring the time it takes for the sound to “bounce back” Some marine life also uses this method.

Echo sounder and multibeam sonar Figure 9.11

Satellites: provide great range and speed in collecting data

Satellite Radar Use of space-based radar to reflect off ocean surface, giving a very precise sea surface profile; sea surface profile anomalies closely mimic the underlying seafloor profile

Sonar helps us map the ocean floor

Observing the Ocean Floor http://www.whoi.edu/visualWHOI/observing-the-ocean Alvin takes you there https://vimeo.com/191864908?from=outro-embed

Main Features

Features of the Ocean Floor What is the deepest place in our oceans? What type of plate boundary makes deep oceanic trenches? Where is the sediment carried by rivers deposited in our oceans? What type of plate boundary is located at mid-ocean ridges? How does Earth’s climate effect sea levels?

Continental Shelf The continental shelf the gently sloping edge of the continent. Ocean water is shallow on the continental shelf.

Continental Slope The descending slope which connects the sea floor to the Continental shelf. This is still considered to be part of the Continent.

Continental Rise A gentle slope with a generally smooth surface, built up by the shedding of sediments from the continental block, and located between the continental slope and the abyssal plain.

The Sea Floor Continental Margin – shallow area made of continental crust Deep-Ocean Basin – deep area made of oceanic crust

Abyssal Plain Abyssal plains are flat or very gently sloping areas of the deep ocean basin floor. They generally lie between the foot of a continental rise and a mid-oceanic ridge

Underwater mountain range Mid-Ocean Ridge Underwater mountain range

Valley from oceanic seafloor spreading Rift Valley Valley from oceanic seafloor spreading

Underwater mountains formed from underwater volcano / plateau Seamount / Gyout Underwater mountains formed from underwater volcano / plateau

Trench Long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor.

Mariana Trench The deepest part of the world's oceans The deepest location on the surface of the Earth's crust It has a maximum depth of about 10,911 meters, or 11 kilometers. http://www.mirror.co.uk/news/world-news/incredibly-rare-ghost-fish-filmed-8351082

While we know relatively little about our oceans, the Mariana Trench is the least explored region of the ocean. The Mariana Trench is the deepest segment of the ocean, particularly at its deepest point entitled the Challenger Deep, which reaches down to a whopping 6.85 miles. What we do know about the Mariana Trench is fascinating – it’s filled with strange and unique creatures that have accustomed to the intense pressure of the water and the extreme temperatures found at its depths, like the anglerfish. Although we know more about the Mariana Trench now, than at any other point in history, it’s the least explored place on Eart