We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byLillian Western
Modified about 1 year ago
Sea Floor & Sediments Measuring the Depths Soundings Echo Sounder
Measuring the Depths Modern Tools ROV’s LADS Side-scan Sonar Satellites
Sea Floor Bathymetry
Continental Margin Active margin Leading margin Pacific-type Convergent boundary Continental shelf is narrow and irregular
Continental Margin Passive margin Trailing margin Atlantic-type Divergent boundary Sediment build-up on shelf
Shelf Break & Slope
Turbidity Currents Turbidites
Continental Rise Atlantic, Indian, and Antarctic Oceans Not usually found at active margins
Ocean Basin Floor
Abyssal Hills & Seamounts Abyssal hills Most common topographic feature < 1000m Seamounts Steep-sided volcanoes > 1000m
Abyssal Hills & Seamounts Guyots (gee-ohs) Flat-topped seamounts
Sediments Rate of accumulation Distribution Source & abundance Chemical composition History
Size & shape Influences sinking rate and travel time
Particle Size Particle aggregation Electrical attraction Fecal pellets 2200x
Location Neritic Continental margins & islands Pelagic Found on the deep sea floor
Rates of Deposits Neritic Sediments Highly variable River estuaries Quiet bays Relict Sediments
Rates of Deposit Pelagic Sediments Slower than neritic 500-600 m
Source & Chemistry 4 sources: 1. Preexisting rocks 2. Marine organisms 3. Seawater 4. Space
Lithogenous Sediments Terrigenous sediments Fine to coarse Most common Weathering of rocks Transport by rivers, winds, volcanoes and glaciers
Lithogenous Sediments Terrigenous sediments Dominant neritic sediment Clear size distribution
Lithogenous Sediments Pelagic lithogenous sediments Abyssal clay 70% clay-size particles 0.1 cm per 1000 years! Red clay Due to oxidation of iron
Lithogenous Sediments 4 types of clay minerals: 1. Chlorite
Lithogenous Sediments 4 types of clay minerals: 2. Kaolinite
Lithogenous Sediments 4 types of clay minerals: 3. Illite
Lithogenous Sediments 4 types of clay minerals: 4. Montmorillonite
Biogenous Sediments Fine to coarse 2 nd most common Shells & skeletons CaCO 3 [calcareous] SiO 3 [siliceous] Oozes
Biogenous Sediments Coccolithophorids Pteropods Foraminfera Lysocline
Carbonate Compensation Depth The depth at which the amount of calcareous material preserved falls below 20% of the total sediment
Biogenous Sediments Diatoms Radiolarians
Hydrogenous Sediments Derived from chemical reactions in the water
Hydrogenous Sediments Carbonates Limestone-type deposits Shallow, warm water Ooliths
Hydrogenous Sediments Phosphorites Phosphorus in the form of phosphate Continental shelf & slope
Hydrogenous Sediments Salts High rate of evaporation in shallow areas Carbonate salts, sulfate salts, then chlorides
Hydrogenous Sediments Manganese nodules Manganese, iron, nickel, cobalt & copper
Cosmogenous Sediments Sediments derived from space
Lithification Formation of sedimentary rock Temps <200ºC
Diagenesis Chemical changes of sediments when they react with seawater
Sampling Methods Dredges Large bulk samples Benthic organisms
Sampling Methods Grab samplers Mud & sand Quantitative sampling
Sampling Methods Corers Gravity corer 1-2 m cores
Sampling Methods Corers Piston corer Up to 20 m cores
Sampling Methods Corers Box corer Large, undisturbed samples Door
Sampling Methods Platform drilling JOIDES Resolution 1100 m cores
Sampling Methods Acoustic profiling
Sediments as Historical Records Paleoceanography Chemistry of biogenous sediments Ratio of 18 O: 16 O Proportion of these in skeletons reflects abundance of isotopes in water
Seabed Resources Sand & Gravel Annual world production = 1.2 billion metric tons Only significant seabed mining done in the US
Seabed Resources Phosphorite Mined to produce phosphate fertilizers Substantial source in Onslow Bay, NC
Seabed Resources Sulfur Used for production of sulfuric acid
Seabed Resources Coal Produced by burial of plant material in areas of low oxygen Peat
Seabed Resources Oil & Gas Represent >95% of the value of all resources extracted from the sea floor Sedimentary rocks 85-180 million years old
Seabed Resources Gas Hydrates Combo of natural gas (CH 4 ) and water Ice-like structure
Seabed Resources Manganese Nodules Manganese, copper, nickel & cobalt Cobalt is of particular interest
Chapter 4 The Sea Floor and Its Sediments. 4.1 Measuring the Depths Methods for measuring depths: Hand line and wire marked with fathoms, with a lead.
Introduction to Oceanography
Sediments. Sediment thickness of ocean floor Very thin –Mid-Atlantic ridge Very thick –Smooth sea floor.
The Sea Floor and Its Sediments An Introduction to the World’s Oceans Sverdrup et al. - Chapter Four - 8th Ed.
Oceans. Pacific largest Atlantic Indian Arctic smallest Name the Oceans.
Oceanography Stratigraphy 2. Terrigenous Sediments (Lithogenous) 3. Biogenous Sediments 4. Calcareous Ooze 5. Siliceous Ooze 6. Hydrogenous Sediments.
Earth Science, 10e Edward J. Tarbuck & Frederick K. Lutgens.
An Invitation to Marine Science, 7th
© 2012 Pearson Education, Inc. Earth Science, 13e Tarbuck & Lutgens.
Chapter 5: Marine Sediments Fig Sediments reveal Earth history Sediments lithified Mineral composition Sedimentary texture Past climate Plate motions.
Chapter 5 - Sediments Distribution of sediments on the sea floor
1 Distribution of sediments Distribution of sediments Seabed Resources Seabed Resources Sediments are particles of organic or inorganic matter that accumulate.
© 2016 Cengage Learning. All Rights Reserved. 5 Oceanography, An Invitation to Marine Science | 9e Tom Garrison Sediments.
Today: Chapter 17, part I Earth beneath the Ocean Techniques of mapping the ocean floor Which parts make up a continental margin, and what is the difference.
CH 14.1 The Ocean Floor Oceanography – the study… 71 % of earth covered by oceans Southern Hemisphere is 81 % water Northern Hemisphere is 61 % water 4.
Ocean Basins Structure of the Oceans From Continental Shelf to Abyssal Depths.
Sediments Chapter 5. Sediments Particles of organic or inorganic matter that accumulate in a loose, unconsolidated form. Sediments are classified by particle.
Sediments Sediment particles that accumulate in a loose, unconsolidated form. Originate from weathering and erosion of rocks activity of living organisms.
SEDIMENTS Text Book – Chapter 5 Why do we care about oceanic sediments? -Continents are sites of erosion; -Oceans are sites of depositions; -Therefore.
© 2011 Pearson Education, Inc. CHAPTER 4 Marine Sediments.
Chapter 4 Marine Sediments
CHAPTER 4: Marine Sediments Fig. CO-4 S. Marine sediments Eroded rock particles and fragments Eroded rock particles and fragments Transported to or produced.
Place these notes in your Notebook.
CHAPTER 4: Marine Sediments Fig. CO-4. Marine sediments Eroded rock particles and fragments Eroded rock particles and fragments Transported to ocean Transported.
Marine Sedimentation. Streams Rivers Glaciers Landslide (Gravity)
Chapter 5: Marine Sediments Fig Marine sediments Eroded rock particles and fragments Transported to ocean Deposit by settling through water column.
© 2009 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their.
Marine sediments Eroded rock particles and fragments Transported to ocean Deposit by settling through water column Oceanographers decipher Earth.
Marine Sediments Chap 5.
Oceanography 101, Richard StricklandLecture 5© 2006 University of Washington 1 Sediments of the Sea Floor Figure 3.20.
Oceans – Part I Introduction Composition of Seawater Features of the Sea Floor Sediments.
Earth Science 14.3 Seafloor Sediments
Bellringer Explain in complete sentences what are pros and cons of coal energy use.
Multimedia Manager A Microsoft® PowerPoint® Link Tool for forOceanography An Invitation to Marine Science 6 th Edition by Tom Garrison
Chapter 4 Marine Sedimentation ©2003 Jones and Bartlett Publishers.
The Ocean Floor Ch. 23.
OCEAN ____________ Chapter 12. ________ enter the ocean through rivers, glaciers, waves, winds, dissolution of ___________ particles, and chemical reactions.
Warm Up 2/10/09 1)Which regions are thought to be the most level places on Earth? a. mid-ocean ridgesc. continental slopes b. deep-ocean trenchesd. abyssal.
14 Chapter 14 The Ocean Floor. The Blue Planet 14.1 The Vast World Ocean Nearly 71 percent of Earth’s surface is covered by the global ocean. Oceanography.
1. Today, ships use echo sounding, or sonar, to find the distance to the ocean floor. By tracking how long it takes for the signal to reach the bottom.
Study Guide available! Web site (dusk.geo.orst.edu/oceans) Go to the syllabus page and click on the Study Guide for Test#1.
Ocean-Floor Sediments (19.3)
Chapter 4 Marine Sedimentation.
Chapter 5 Sediments. © 2006 Brooks/Cole, a division of Thomson Learning, Inc. Look For The Following Key Ideas In Chapter 5 Sediment is particles of organic.
Sediments! ☺ January 19, Wentworth Scale of Grain Size Boulder Cobble Pebble Granule Sand Silt Clay.
Marine Sediments and Sedimentation. Tools used to collect and study Sediments How can sediment be collected from the sea floor? How can it be collected.
The Ocean Floor Chapter 14 pg 393.
Exit Choose to view chapter section with a click on the section heading. ►Continental-Shelf SedimentsContinental-Shelf Sediments ►Deep-Ocean SedimentsDeep-Ocean.
Chapter 23.1 Studying the Ocean Floor
© 2017 SlidePlayer.com Inc. All rights reserved.