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What is the main focus of Marine Geology?
What is the main focus of Marine Geology?
How does Geological Oceanography differ from Marine Geology?
How does Geological Oceanography differ from Marine Geology?
Which of the following best describes the analogy of the ocean as a punch bowl?
Which of the following best describes the analogy of the ocean as a punch bowl?
What does the term 'paleoceanography' refer to?
What does the term 'paleoceanography' refer to?
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Which of the following is NOT a tool commonly used in Geological Oceanography?
Which of the following is NOT a tool commonly used in Geological Oceanography?
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Which of the following processes is associated with Marine Geology?
Which of the following processes is associated with Marine Geology?
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In what context are the terms 'Marine Geology' and 'Geological Oceanography' often used interchangeably?
In what context are the terms 'Marine Geology' and 'Geological Oceanography' often used interchangeably?
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Which statement reflects a misconception about Marine Geology?
Which statement reflects a misconception about Marine Geology?
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What was a key finding of Sir John Murray during the Challenger expedition?
What was a key finding of Sir John Murray during the Challenger expedition?
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Which ships conducted significant polar research under James Ross?
Which ships conducted significant polar research under James Ross?
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How did oceanographic research find funding during the early 20th century?
How did oceanographic research find funding during the early 20th century?
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What advancements were made in echosounding technology during WWII?
What advancements were made in echosounding technology during WWII?
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What was the primary focus of oceanography for about 70 years after the Challenger expedition?
What was the primary focus of oceanography for about 70 years after the Challenger expedition?
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Which expedition is often associated with the initial major oceanographic research?
Which expedition is often associated with the initial major oceanographic research?
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What misconception did Sir John Murray's findings fail to correct regarding the deep ocean?
What misconception did Sir John Murray's findings fail to correct regarding the deep ocean?
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What is the primary time-scale of interest for geological oceanography?
What is the primary time-scale of interest for geological oceanography?
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Which of the following was a common reason for dismissing Wegener's theory of continental drift?
Which of the following was a common reason for dismissing Wegener's theory of continental drift?
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Why are marine geologists often looked down upon by land geologists?
Why are marine geologists often looked down upon by land geologists?
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What is the main reason most marine geology is limited to ages less than about 175 million years?
What is the main reason most marine geology is limited to ages less than about 175 million years?
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Which technology do marine geologists depend on more than land geologists?
Which technology do marine geologists depend on more than land geologists?
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What role does paleoceanography play in oceanography?
What role does paleoceanography play in oceanography?
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Which statement best describes how geological oceanographers are perceived by other oceanographers?
Which statement best describes how geological oceanographers are perceived by other oceanographers?
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What is a significant aspect of paleoclimate studies relevant for climatology?
What is a significant aspect of paleoclimate studies relevant for climatology?
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What critical information from the past do paleoceanographers study?
What critical information from the past do paleoceanographers study?
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What primarily causes the measured height of the sea at a location to vary?
What primarily causes the measured height of the sea at a location to vary?
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How does the influence of gravimetric anomalies differ from bottom topography?
How does the influence of gravimetric anomalies differ from bottom topography?
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Which optical sensors measure reflected light from the surface?
Which optical sensors measure reflected light from the surface?
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What can be identified using the whole spectrum of light in optical measurements?
What can be identified using the whole spectrum of light in optical measurements?
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What happens to physical drivers such as ocean currents when taking long term data averages?
What happens to physical drivers such as ocean currents when taking long term data averages?
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Which of the following represents a signal rather than noise in oceanographic data?
Which of the following represents a signal rather than noise in oceanographic data?
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What does measuring the ratio of different wavelengths in water help determine?
What does measuring the ratio of different wavelengths in water help determine?
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What type of seafloor characteristic can affect the existence of mounds or depressions?
What type of seafloor characteristic can affect the existence of mounds or depressions?
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What is the primary advantage of piston corers over gravity corers?
What is the primary advantage of piston corers over gravity corers?
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Which factor does NOT contribute to the depth of sediment depth that a corer can achieve?
Which factor does NOT contribute to the depth of sediment depth that a corer can achieve?
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What is the role of the term "piston" in a piston corer?
What is the role of the term "piston" in a piston corer?
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Which satellite is known for providing detailed and accurate data on sea surface levels?
Which satellite is known for providing detailed and accurate data on sea surface levels?
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What capability do submersibles provide that ROVs typically do not?
What capability do submersibles provide that ROVs typically do not?
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What is a significant limitation of deep ocean drilling operations?
What is a significant limitation of deep ocean drilling operations?
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How does the TOPEX/Poseidon satellite enhance our understanding of marine geology?
How does the TOPEX/Poseidon satellite enhance our understanding of marine geology?
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What is the expected sedimentation rate in deep ocean areas as mentioned?
What is the expected sedimentation rate in deep ocean areas as mentioned?
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What is the primary function of Side-scan sonar?
What is the primary function of Side-scan sonar?
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Which equipment is best for obtaining detailed bottom images over wide swathes?
Which equipment is best for obtaining detailed bottom images over wide swathes?
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What describes the usage of air guns in seismic surveys?
What describes the usage of air guns in seismic surveys?
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What does 'TWT' represent in seismic surveying?
What does 'TWT' represent in seismic surveying?
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How does Synthetic Aperture Sonar differ from traditional sonar?
How does Synthetic Aperture Sonar differ from traditional sonar?
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What is the result of using Single Beam Echo Sounding?
What is the result of using Single Beam Echo Sounding?
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Which method is typically used to look beneath the seafloor?
Which method is typically used to look beneath the seafloor?
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What is the significance of the term 'Aperture' in Synthetic Aperture Sonar?
What is the significance of the term 'Aperture' in Synthetic Aperture Sonar?
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Study Notes
Unit 1: Introduction to Marine Geology/Geological Oceanography
- Course Introduction: The course covers marine geology, geological oceanography, and paleoceanography.
- Definitions: Marine geology examines the characteristics and history of the Earth's sea-covered parts. Geological oceanography studies the history and tools of marine geology, including paleoceanography. Paleoceanography studies the history of the oceans in the geological past.
- History of Geological Oceanography: The study of the oceans' history and geological processes.
- Tools of Geological Oceanography: Instruments and techniques used in the field.
Marine Geology and Geological Oceanography
- Scope: The study of the character and history of the Earth's water-covered portions, from coastal areas to deep-sea trenches and abyssal plains.
- Processes: Geological processes shaping ocean floors, oceans' water, and climate.
- Extends beyond the water: The study also includes uplifted marine sediments, plate tectonics, ophiolites, and paleoclimates.
Ocean as a Punch Bowl
- Bowl: Ocean basins. Shaped by plate tectonics and modified by weathering, erosion, and sediment deposition.
- Punch: Water, dissolved particles (living and non-living, e.g., silt, bacteria, whales).
Marine Geology vs. Geological Oceanography
-
Interchangeable use: Often used interchangeably, but sometimes distinguished based on origin:
- Geologists interested in oceans versus oceanographers interested in geological processes.
- Interests and areas of focus: Geology or oceanography?
Interests in Marine Geology/Geological Oceanography
- Marine Geology: Plate tectonics, volcanoes, earthquakes, minerals, rocks, and terrigenous sediments.
- Geological Oceanography: Physical, chemical, and biological processes (biogeochemistry). These processes affect geology (mineral precipitation, sedimentation, diagenesis) and climate.
Time Scales of Interest
- Geological Oceanography: Primarily focused on the present and near future (modern sedimentation, coastal processes, biogeochemical cycles, and climate).
- Marine Geology: Examines oceanographic processes extending further back in time, becoming the domain of geologists.
- Marine Geology limitations: Primarily interested in the last ~175 million years.
Marine Geology vs. Land Geology
- Historical Focus: Land-based geologic studies have historically been more common due to practical logistics.
- Limited Seafloor Data: There is a scarcity of older seafloor data.
- Logistics: Doing geology on land is practically easier than in the more challenging ocean environment.
Other Differences Between Marine and Land Geologists
- Data Access: Marine geologists rely more on remote sensing and satellite data due to accessibility constraints that limit direct sampling.
- Tools and Techniques: Multi-beam technology, sonar, and underwater vehicles are increasingly used.
Geological Oceanographers vs. Other Oceanographers
- Pecking Order: Geological oceanographers are often seen as having a lower standing compared to other oceanographers (physical, biological, chemical).
Paleoceanography
- Definition: The study of the history of oceans in the geologic past, relating to circulation, chemistry, biology, geology, and patterns of sedimentation and productivity.
- Applications: Provides a critical time dimension for understanding past climates and allowing for predictions of future climates. Using past climates, current climate models can be tested.
Early Exploration Stage
- HMS Beagle (1831-1836): Darwin's voyage.
- Polar Research (e.g., ships "Erebus" and "Terror"): Depth soundings.
The First Oceanographic Expedition
- Challenger Expedition (1872-1876): A significant step in early oceanography. Sir John Murray—a key figure in Marine Geology—recognized marine sediments, deep-sea oozes, and plankton assemblages
After the Early Periods
- 70 Years Later (post-Challenger): Continental drift was initially disputed. Oceanography technology was still expensive and funding was a limitation.
- Early 20th Century: Linking research to national interests/pride to gain funding and propel oceanographic work.
- WWI: Restored German pride via acoustic profiling.
- WWII: Acoustic sounding improved to detect submarines to use its technology in topographic mapping.
1950s-1960s
- Marine Explosion Seismology: Use of explosives and studying sediments (Replaced by air-guns later). Discovery of fracture zones.
- Isotope Use: Paleotemperature analysis, highlighting Cesare Emiliani's role as a paleoceanographer.
1970s-Present
- Deep Ocean Drilling: The Glomar Challenger and Joides Resolution enabled deep-sea core sampling, significantly advancing paleoceanography.
- International cooperation: Large international programs for multi-year research became more common.
- Submarine Technology: Underwater vehicles and satellites aided exploration and remote-sensing.
- Computer Modeling: Advanced computer models help study and understand complex ocean processes.
Deep Ocean Drilling Project (DOCP)
- Glomar Challenger (1968): Pioneering research ship.
- Joides Resolution: Later vessel for deep-sea core sampling.
International Ocean Discovery Program (IODP)
- From 2013: Continuation of deep-sea core sampling—using the Joides Resolution and Chikyu to sample deep-sea cores.
Modern Oceanographic Research
- International Cooperation: Increased international collaboration due to the high cost of modern oceanographic research.
- Modern Tools: Underwater vehicles (submersibles, ROVs, AUVs), satellite remote sensing, supporting technologies are crucial.
Collecting Samples of Sea Floor
- Early Bottom Dredges: Scraped sediments in wire/canvas bags.
- Grab Samplers: Took "bites" out of the seafloor to collect sediments.
- Gravity Corers: Used weighted core barrels to drive the core into the seafloor.
- Piston Corers: Can collect much longer cores than gravity corers by freely falling.
Remote Sensing Methods:
- Altimeters: Measure altitude above the sea surface—crucial in geophysics and geology.
- Optical Sensors: Use light's spectrum for photography to capture information about coastlines, sediments, and shallow water features.
- Other Sensors: Methods measure ratios of wavelengths to assess water contents (suspended sediments, dissolved matter, chlorophyll).
Sounding Equipment: Studying the Sea Bed
- Single Beam Echo Sounding: Maps along straight lines.
- Side-Scan Sonar: Provides scans in two or more swaths to visualize wider areas.
- Synthetic Aperture Sonar (SAR): Multiple sonar data recordings allowing a more detailed representation of the bottom than single-beam sonar.
- Multi-Beam Echo Sounders (MBES): Provide a wide range of swaths and a more complete mapping of the bottom.
Seismic Surveys
- Sound Source: Usually air-guns—generating strong, low-frequency sounds that penetrate deeper into the seafloor
- Acoustic Receivers (Streamers): Measure signals that are reflected off various layers in the ocean floor.
Supporting Technologies
- GPS: Geographic Positioning System – crucial for knowing the location of ocean floor measurements.
- Computer Modeling: Analysis and modeling of seismic signals and other oceanographic data, including modeling of past climates.
- Isotopic Analysis: To determine past climates and other ecological information.
- Sediment Traps/Buoys: Monitoring and collecting physical properties of the sea bottom and biological communities within it.
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Description
Test your knowledge on marine geology and geological oceanography with this insightful quiz. Explore key concepts, historical expeditions, and tools used in the field. Discover how these disciplines interrelate and their significance in understanding ocean processes.
