NEW WQ - Ocean Info

For Kenny: "Later" just means, to me at least, the term probably won't be in the tryout lmao. You can refrain from studying those. "Finish" Just means I haven't finished making the card yet.

What % of all water is ocean?

What % of the Earth’s surface area is ocean?

All water: 97%

Surface area: 70.8%

later: How much ocean water is there?

~332,500,000 cubic miles

Name every ocean.

• Pacific

• Atlantic

• Indian

• Arctic

• Antarctic

Biggest ocean by surface area and volume

Pacific

Surface area: 63.8 million square miles

Volume: 171 million cubic miles

Hottest and coldest oceans and why

Hottest: Indian ocean. Does not connect to Arctic ocean (so very little polar water received); sits at equator

Coldest: Arctic ocean. Receives little direct sunlight, and a good portion of what does hit, is reflected away via the albedo effect.

The ocean as a heat resevoir

Absorbs more than 90% of all excess heat trapped by greenhouse gases in Earth's atmosphere.

High thermal inertia (tendency to resist changes in temperature), so can absorb lots of energy before warming up.

Also, water just generally has a pretty high specific heat capacity, and there is a lot of it in the ocean.

How and why is the ocean so salty?

Land runoff (main): Rainwater is slightly acidic (reacts with CO2 to make carbonic acid), and erodes salt-containing rocks that runoff into the ocean via streams/rivers.

Seafloor vents: Ocean water seeps into seafloor openings, and is heated by magma, causing it to dissolve/pick up metals and minerals from the rock. It then go back into the ocean via vents.

Underwater volcanoes: Eruptions directly release minerals into ocean.

The ocean and its ecosystems as a carbon sink

The world’s largest carbon sink, absorbing ~31% of CO2 emissions.

Caused by the ocean carbon pump, which comprises:

Solubility aka physical pump: From ocean circulation. Colder temps=greater gas solubility; especially near poles, once CO2 dissolves in water (into DIC (dissolved inorganic carbon)), it’s carried via thermohaline circulation into deeper ocean

Biological pump: Transfers CO2 to seabed via food web (starting w/ CO2-siphoning phytoplankton) and marine snow; long-term storage. Sensitive to disturbances; can re-emit CO2 into atmosphere

Mangroves/seagrasses sequester CO2 at rates up to 4x terrestrial forests.

How does ocean acidification work?

CO2 in atmosphere and HO2 in ocean react to form carbonic acid (H2CO3). It’s unstable, and dissociates into H+ (the acid) and HCO3.

(later) Mariana Trench

• Deepest ocean trench (1580 miles deep), in Pacific ocean.

• Absolute bottom = “challenger deep” (deepest point of seabed)

• Formed from subduction of tectonic plates; Pacific plate under Mariana plate.

Phytoplankton and zooplankton

Phytoplankton: Autotrophic (releases O2; 50% of all O2 in atmosphere). E.g. diatoms, cyanobacteria, dinoflagellates

Zooplankton: Feed on phytoplankton (consumes O2). 2 types: Holoplankton and meroplankton (plankton for full life cycle and plankton for portion of life cycle, respectively) E.g. krill, protozoans

Average depth of ocean

Deepest ocean

Shallowest ocean

Average depth: 12,080ft

Deepest: Pacific

Shallowest: Arctic

Sound travel speed in water and why

Sound travels ~4.5x more quickly in water.

All sound is derived from the collision/vibration of particles; basically transports the vibration energy each collision.

In air, each particle is farther apart. Meanwhile, for water, particles are a lot closer together by default, allowing the vibrations to travel a lot quicker.

What causes currents?

• Density differences: From temp and salinity. Thermohaline circulation (see card) to cause large-scale currents.

• Wind: from, e.g. the sun (heats air near equator (creating low-pressure areas), while cooler (heavier) air at poles creates high-pressure areas. Movement of air from high to low (makes wind) cause surface currents.

How do tectonic plates move?

Ridge push: Newly-formed plates are warm and have a higher elevation than the cooler (denser) material further away from an ocean ridge. Gravity causes the higher plate at the ridge to push away.

Slab pull: At destructive plate margins, the denser oceanic plate sinks into the mantle under the influence of gravity, pulling the rest of the plate along with it.

Coriolis effect

Instead of circulating in a straight pattern, air etc deflects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths. (cause by Earth's rotation, which makes certain places spin slower)

Influences wind/wave patterns.

later: Major ocean currents

Oceanic basins

Anywhere on Earth covered by seawater.

later:

Cyclone

Hurricane

Typhoon

Cyclone: Air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Warm-water, low-pressure areas caused by sun's heating causes air to rise and condense. Cold air rushes in to fill the void, but is bent inward/spiraled upward due to Coriolis effect. This needs to repeat for cyclone to continue. South Pacific/Indian Oceans.

Hurricane: Type of tropical cyclone. Describes exact same thing, except originates from East Pacific

Typhoon: Type of tropical cyclone. Describes exact same thing, except originates from West Pacific.

later: How do earthquakes form?

Mid-ocean ridges

A continuous range of underwater volcanoes that wraps around the globe.

They occur along divergent plate boundaries, where new ocean floor is created as tectonic plates spread apart. As they separate, molten rock rises to the seafloor, causing volcanic eruptions of basalt.

E.g. mid-atlantic ridge and east pacific rise.

(later) Types of waves (5)

Wind wave: high-frequency and generated near/due to a wind source

Swell:

Seiche wave:

Capillary wave:

Surface gravity wave:

(later) Breakwaters

Dykes

(later): Seawalls

Levees

(later): Why is the ocean largely blue?

later: Swell

later: Fetch

Wave refraction vs diffraction

Refraction: When wave starts to interact with the sea bed (which slow the waves down), causing them to bend toward shore. Shallower water=slower, shorter waves.

Diffraction: The change in direction after a wave crest has passed either through an opening and then starts radiating from that opening as circle segments, or around an obstacle.

Constructive interference

Destructive interference

1: When two or more overlapping waves meet, and their crests/troughs align to create a single wave with larger amplitude than either of them.

• Occurs when the phase difference between the waves are an even multiple of pi.

2: When two overlapping waves meet out of phase (aka the crest of one aligns with the trough of another) reducing or canceling out their combined amplitude.

• Superposition principle (total wave displacement is= sum of the displacements of the individual waves.)

• Occurs when the phase difference between the waves are an odd multiple of pi

(later): Wave shoaling

Why is stratification less pronounced on the ocean? (2.5)

A few reasons include:

• Wind-forced mechanical mixing

  • E.g. downwelling/upwelling (up/down movement of water)

• Seasonal temps and fluctuation

Freezing point of sea water and why

Freezing: -1.8C (28.4F), which is lower than the usual 31F.

“Freezing point depression” (when added solutes drop freezing point) Due to higher salinity. The salt molecules arrange themselves around water molecules, preventing them from interacting and forming ice crystals. So, colder temps needed.

Average density of sea water

1.025kg/L

later: Stokes drift

later: Ekman spiral

Thermohaline circulation and effects

Definition: Deep-ocean currents driven by differences water density (which is controlled by temps (thermo) and salinity (haline)).

• Begins in polar regions. As ice forms, salt is excluded, meaning surrounding water gets saltier, leading to higher density/for the water to sink. Surface water pulls in to replace it, and this repeats.

  • The water moves around/is a major driver of global conveyer belt.

Effects:

• Regulates global climate by redistributing heat and nutrients

(later): At equilibrium, how much of its most abundant gases are in the ocean?

Garbage patches

What are the 5 main ones?

Garbage patches are caused by gyres, rotating ocean currents that trap marine debris (mostly microplastics (due to photodegradation weakening bonds/breaking down plastics) and fishing gear).

• Great Pacific (The largest garbage patch)

• South Pacific

• North Atlantic

• South Atlantic

• Indian Ocean

Most biodiverse ocean

Most biodiverse body of water (and about it)

Pacific

"The Coral Triangle”, located right at Southeast Asia. Has:

• more than 76% of the world's shallow-water reef-building coral species

• 50% of its razor clam species

• six out of seven of the world's sea turtle species

• world's largest mangrove forest: the Sundarbans.

What are the most abundant types of garbage in garbage patches? Why, and what percent are they?