Ocean101-Ch04 - Some Important Concepts in Chapter 4 !...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Some Important Concepts in Some Important Concepts in Chapter 4 Chapter 4 ! Bathymetry — the measurement of water depths and mapping of sea floor features — uses several types of technology. ! The sea floor has two distinct regions: continental margins and deep- ocean basins. ! Continental margins are the relatively shallow areas of the ocean floor near shore. Geologically they are part of the adjacent continent. Passive vs. active continental margins are distinguished by their plate tectonic setting. Major features : continental shelf, shelf break, continental slope, continental rise, submarine canyons, submarine fans. ! Deep-ocean basins differ from the continental margins in tectonic origin, history, and composition. Most important features of the deep- ocean basins were formed by plate tectonic processes. Major : mid-ocean ridge, transform faults & fracture zones, hydrothermal vents, abyssal plain, abyssal hills, seamounts & guyots, oceanic trench & volcanic arc. High Tech Methods for Surveying the Deep Sea Floor for Surveying the Deep Sea Floor Ocean Planet (Smithsonian, NASA)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Sophisticated technology — such as these deep- diving bathyscaphes bathyscaphes * — allows scientists to study even the deepest areas of the ocean floor. Alvin Trieste *= “deep ships deep ships Bathymetry : Measuring Ocean Depths : Measuring Ocean Depths Early bathymetric studies were often performed using a weighted line dropped to measure depth. Advances in Bathymetry Echo sounding Multibeam systems Satellite altimetry
Background image of page 2
3 Echo sounding is a method of measuring depth using powerful sound pulses. The time it takes for the sound pulse to travel to the sea bed and bounce back is a measure of the depth. Distance = Rate x Time Bathymetry Bathymetry Fig. 4.2a, p. 79 Bathymetry Bathymetry Multibeam Multibeam systems systems can provide more accurate measurements than echo sounders. Multibeam systems collect data from as many as 121 beams to measure the contours of the ocean floor. Fig. 4.3, p. 79 Bathymetry Bathymetry Satellite altimetry is an indirect way of measuring depth and detecting sea floor features. Satellites measure the sea surface height from their orbits by bouncing rapid pulses of radar energy off the ocean surface. Sea floor features like submerged mountains have more mass than sea water.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/09/2012 for the course OCEA 101 taught by Professor Gwynethjones during the Winter '12 term at Bellevue College.

Page1 / 12

Ocean101-Ch04 - Some Important Concepts in Chapter 4 !...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online