Fundamentals of Marine Science Exam 2 Review
What techniques are used to monitor waves along a coastline?
Accelerometer buoy Radarsat Platform with instruments wave staff Bottom mounted pressure transducer
Describe how carbon atoms from the CO2 you exhaled could end up in the shells of a shell-building organism such as a lobster or clam.
After you exhale CO2, it will enter the atmosphere and eventually will find its way to cold ocean waters, such as the North Atlantic. From there it'll dissolve into the ocean water and combine with H2O to produce carbonic acid. This carbonic acid will then break apart into hydrogen ions, bicarbonate ions, and carbonate ions. The carbonate ions will then combine with calcium ions present in the water and form calcium carbonate, which is used by shell-building organisms, like lobsters and clams, to create their shells and inner skeletons.
What forces create storm surges along coastlines?
Barometric: The level of the water rises underneath the storm. Wind stress: blows toward shore and pushes water up on the shore. Both cause the mean water level to rise.
When CO2 dissolves in the ocean, it combines with water molecules to produce what 3 ions?
Bicarbonate, hydrogen, and carbonate ions.
Compare the ocean sediment map with the Deep Ocean Conveyor Belt Map. How can you use these maps to explain the lack of calcareous sediments accumulating in the deepest parts of the oceans and especially the north Pacific.
Carbon sinks are present in the same areas where carbon dissolves into the water, and these areas are in the Northern Atlantic and the Southern Arctic Ocean. Carbon leaves the water at tropical waters near the equator, and this pattern is present in both maps in the upwelling zones (Pacific Ocean and Indian Ocean). Carbon sinks in both the N. Atlantic and Antarctic Pacific oceans on both maps. You can also see the high source of Carbon along the coast of western Africa in the Atlantic Ocean Tropical waters have low amounts of CO2 diffusing into sea surface waters. Cold southern and northern oceans are absorbing more CO2 from the air. There are sources of CO2 along equatorial currents and upwelling. CO2 sinks are found along where new surface water sinks at Greenland and Antarctica as bottom water in the Deep Ocean Conveyor belt. In the areas where the currents change from being a surface current to a deep current, we see a carbon sink, meaning that more carbon is moving to the deep sea where it will stay. The map indicates that there is far more gas exchange between the ocean and atmosphere over areas that have a warm current when compared to a cold current. The correlation between the CO2 flux map and the surface current map shows that where there are surface currents, there tends to be a higher flux of CO2 being transported into the atmosphere. At carbon sinks and downwelling occurs, shallow water is brought into the deep ocean and CO2 is dissolved, leading to less CO2 being evaporated and more CO2 being dissolved where there are deep ocean currents.
Where is most carbon stored in the ocean basins?
Deep Ocean 25,000,000 gigitons
Why are particles such as detritus, sometimes called marine snow, so important in bringing carbon down into the twilight and deep ocean zones?
Detritus is important in bringing carbon down to the twilight zones because it possesses the carbon that isn't struck in the microbial carbon loop. When not consumed, it settles, allowing organisms in the twilight zones to have carbon molecules to consume. Microbial respiration of this sinking material returns C:N:P back to the water column for reuse in upwelled waters. Microbes eat detritus and convert the organic carbon into carbon dioxide and dissolved carbon that marine plants use for photosynthesis. Meanwhile, detritus in the water that is not consumed by microbes or other organisms settle on the seafloor. It also provides a food source, decomposition, and can be sequestered into the largest sink, the sediment. Because it is hard for other forms of carbon to make it into the deep ocean zones. Over time detritus settles on the ocean floor and is preserved, creating carbon-rich sediment that forms limestone and shale, eventually being subducted back into the mantle, beginning the carbon cycle all over again. Some of the marine snow settles on the seafloor and is buried in sediment and can be used as a record of past conditions on Earth. The particles will clump together and sink to the bottom. It is an easy way to transport to the deep sea.
What influence does downwelling have on deep ocean CO2 content and water pH?
Downwelling currents push/transfer dissolved CO2 down into the deep ocean where it will stay moving in slow deep ocean currents along the bottom until it is upwelled, which could take hundreds of years. This process increases the amount of CO2 in the deep ocean.
What are storm surges during coastal storms?
Low-pressure systems Reason water comes to land: the wind has been driving the water for hours and the water has nowhere to go due to shallow land.
How is the "shoreline" position identified along an open coastline?
Mean High Water (MHW) elevation Physical proxies Wet-dry line Dunes
As the carbon moves down through the biological pump, less and less carbon actually makes it down into the deep ocean. How do microbes and zooplankton reduce the amount of carbon that eventually sinks to the ocean bottom?
Microbes and zooplankton reduce the amount of CO2 sinking to the bottom by consumption and cycling of carbon. Most of the carbon remains in the cycle while only a small amount leaves the cycle and sinks. Carbon is taken up into organic matter that eventually decays and also into biominerals such as calcium carbonate. Zooplankton and microbes consume photosynthetic organisms. Zooplankton and higher trophic levels will then respire CO2 back into the water column after eating sinking marine snow/plankton. Microbes also respire CO2 back into the water column. They can reduce the amount of carbon that eventually sinks to the ocean bottom through sequestration and absorption of CO2. Zooplankton/microbes use carbon in shell/plate/bone formation and consume it in their food. Through the detritus of zooplankton and phytoplankton, organic carbon is brought to seafloor sediments. start off as a coccolithophorids creating CO2 and acid in the water taking it away from the shells
How does ocean temperature affect sea level?
Ocean temperature melts ice sheets and glaciers causing sea levels to rise mostly coming from West Antarctica. Water stores a lot of heat and makes the water less dense
How does ocean acidification affect different types of carbonate-secreting marine organisms?
Organisms with more protective coverings on their shells and skeletons such as crustaceans are less affected by ocean acidification than organisms with less protective shells such as conchs. It can lead to coral bleaching and the loss of important zooxanthellae that corals depend on to survive. Drops in metabolic rate drops in immune response, decreased availability of CaCO3, hypercapnia. Ocean acidification can cause a drop in metabolic rate or immune response that can be harmful to fish. The acidification of the ocean can also change the acoustic properties of the ocean which harms animals that use echolocation to communicate.
What organisms move CO2 into the ocean carbon cycle? By what process?
Phytoplankton brings CO2 into the ocean carbon cycle through photosynthesis.
How do we measure the temperature and heat stored in the ocean?
Satellite altimetry and Argo floats
What is the global trend in sea level over the past century?
Sea level is rising: average of 1-2 mm per year for the 20th century and 3.3 mm per year during the last decade
How is the current sea level along your local coastline defined and measured?
Sea level is the elevation along the shoreline where the ocean meets the land Measured using satellite altimetry
What other oceanographic processes influence relative sea level in an area?
Seasonal Cycles: The effects of variation in sea surface temperature, barometric pressure, and strength/orientation of ocean currents cause seasonal variations in sea level. Florda: Gulf Stream El Nino Waves Tides Strom Surge Wind blowing
Why are storm waves so much more important in changing the coastline than simple day-to-day waves?
Storms transfer energy from the atmosphere to the ocean, driving the mixing of the surface layers.
Know all of the components that result in the total water level along a generic shoreline.
TWL = Mean sea level + Tide + Non-tidal residuals + Wave runup Four concepts: Waves, Tides, Water level anomalies, and sea level rise HAVE EXAMPLES FOR EACH ONE: Wave runups, tides, sea level rise (global/local), water-level anomalies (storm surge, el nino, seasonal effects)
What is ENSO and how might it affect relative sea-level in an area?
The El Niño-Southern Oscillation (ENSO): Warmer water extends to the eastern Pacific. When water warms, it expands, resulting in higher sea levels in the oceans. The upwelling of cold water off the coasts of the Americas is reduced during an El Niño. Fish either die or relocate to regions where they can find more food when this happens.
What is the lysocline and the carbonate compensation depth? How does its depth change between ocean basins?
The carbonate compensation depth (CCD) is the particular depth level in the oceans where the rate of supply of calcium carbonate to the sea floor is balanced by the rate of dissolution. The reason for this is as organic material settles to the water column microbial decomposition is dissolving. It becomes more acidic. Sinking of thermohaline circulation which builds up CO2. The shells dissolve. The lysocline is the depth in the ocean dependent upon the carbonate compensation depth, usually around 3.5 km, below which the rate of dissolution of calcite increases dramatically because of a pressure effect. Biological carbon pump, microbial decomposition. As you get deeper, the water gets more acidic. Acidic water is with depth. All the productivity sinks creating acid. Physical pump. Great ocean conveyor belt - 1200 year water and CO2 water goes up
What is glacial isostasy? How do we measure it in North America? Where is it causing the land surface to rise? Sink?
The glacial isostatic is when glaciers push down on the asthenosphere, creating a depression in the lithosphere where asthenic material beneath it flows out. Extremely accurate GPS measured glacial isostasy. Alaska is rising and mid-Atlantic states are sinking. Why Virginia has bad flooding: we had massive amount of ice which pushed down on the earths crust. Think of it as when someone sits on a couch, the ice caused the land to pop up somewhere else and when the pressure is released the land will go back down.
What influence does upwelling have on surface ocean CO2 content and water pH?
Upwelling brings deep cold water to the surface where the water is warm and some of the dissolved CO2 is released back into the atmosphere.
What are the three primary controls on the amount of energy in surface gravity waves, created by winds.
Wind speed (velocity) Fetch (distance) duration of wind blowing
What are the possible causes for local (relative) sea level to be different than the global average signal?
Winds - The dominant winds in a region affect the shape of the seas. Temperatures - Because hot water is more voluminous than cold water, sea levels in the Tropics may rise faster. Oceanic currents -Changes in oceanic currents caused by global warming could have a direct impact on local sea-level rise. global sea level as we measure it with satellites, it shows that it is going up 2-3mm per year. It not being the same everywhere (relative) ocean absorbing heat so it expands (balloon in a hot car), melting of mountain glaciers
What is the difference between local (relative) and eustatic (global) sea level?
eustatic sea level: satellite data showing a rise in sea level. The distance from the center of the earth to the sea surface. Local sea level: relative sea-level rates based on tide gauge records. The height of the water as measured along the coast relative to a specific point on land
