Marine science overview

Why do water molecules have emergent properties

• Oxygen and hydrogen have unique characteristics on their own

• When they bond to form water molecules, the compound develops new characteristics called emergent properties

What is a result of water having a high heat capacity

Water can resist temperature changes, moderating climate

What happens to the density of water when water freezes

It decreases, and ice floats in water

How do hydrogen bonds contribute to waters property as a universal solvent

• The oxygen atom in water has a partial negative charge while the hydrogen atoms have partial positive charges

• This polarity allows molecules to surround and interact with various ionic and polar substances

Why does ice float on water and what is the ecological significance of it in aquatic environments

• Ice floats on water because its less dense than liquid water

• This occurs because in its solid form water molecules form crystalline structure due to hydrogen bonding

• This structure holds the molecules further apart than in liquid water, resulting in lower density

• Ecological significance is that it acts as an insulting layer preventing water below from freezing solid this allows marine animals to survive under water during cold months

Role of a solvent in a solution

To dissolve other substances

Why does sodium chloride dissolve easily in water

• Partially positive hydrogen of water molecule surrounds the negative chloride ions

• Partially negative oxygen end in water molecule surrounds the positive sodium ion

• This force breaks the ionic bond between sodium and chloride

How does increase in water temperature impacts the solubility of sodium chloride

• As water heats, the molecules move faster and makes it easier for water molecules the ionic bond in sodium chloride

• This causes an increase in rate of dissolution of sodium chloride so the warmer the water, the saltier it gets

How does an increase in seawater temperature affect the solubility of salts

It increases the solubility of salts

Why does warm water dissolve more salt than cold water

Warm water molecules move faster making it easier to break ionic bonds

How does turbulence and wave action affect gas levels in upper levels of ocean

It facilitates the dissolving of gases, increasing the concentration of CO2 and O2 in upper 200 meters

Why is CO2 more soluble in water than O2

CO2 forms carbonic acid in water while O2 does not combine with water molecules

How does temperature affect gas solubility in ocean

Cold water dissolves more gas than warm water

How does atmospheric pressure influence gas solubility in seawater

High pressure increases gas solubility while low pressure causes gases to be lost to the atmosphere

Why is there more oxygen in freshwater and estuaries compared to open ocean

Freshwaters and estuaries have lower salinity allowing for more gases like oxygen to dissolve

How does evaporation and precipitation impact salinity

• Evaporation causes the salinity to increase because the water is lost from seawater solution to the atmosphere, as the water vapors and salts are left behind, causing an increase in salinity

• Precipitation causes salinity decrease because the addition of water (freshwater) dilutes the salinity of ocean surface

Describe one method that would be best to use to neasure water pH level and explain why

• Would use a pH probe which is an instrument that electronically measures the concentration of hydrogen ions in a solution

• This method is more precise and less subjective compared to other methods

Why does the concentration of oxygen increase after the OML layer

• Very low food resources down there so marine organisms respire less

• Temps get near freezing and O2 dissolves best with cold temps

• The pressure increases and in turn so does the solubility of oxygen

Why is warm water saltier than cold water

• As water heats up, molecules move faster

• Makes it easier to break the ionic bonds in salt

• Allows more salts to dissolve in water

Formula for density

Mass/volume

How does temperature affect density of seawater

As temperature increases, density decreases

Thermocline

Layer between warm less dense water, and cold denser water

How do surface temperatures in Arctic compare to those in tropics

Arctic has surface temps around 10 C and cools at 1C while tropics have higher surface temperatures 

How does salinity affect density of water

Increase in salinity, increase in density

Halocline

Layer in ocean where there is a rapid change in salinity with depth

In what conditions would salty water be found on surface of ocean defying usual conditions

In teh tropics with high evaporation rates and higher temperatures occur

Pycnocline

Area of water where density changes quickly with depth

How does water change from liquid to gas in reference to hydrogen bonds and kinetic particle theory

• As liquid absorbs heat that causes molecules to vibrate and move further away from each other

• The more heat absorbed by water, the higher the vibration between molecules

• As a result hydrogen bonds between water molecules break

What is the crust of the earth

Outermost layer of earth made of solid rock

What is the mantle

underneath the crust, hot, semi-solid rock, capable of slow movement

What is the core

make up the center of the Earth; hot, dense, and under great pressure

Which part of core is liquid, which part is solid

Inner core is liquid, outer core is solid

Theory of continental drift

over 300 million years ago all the continents were connected to form “Pangea”

3 pieces of evidence used for continental drift

• Similar fossils of plants and animals are found on continents that are separated by oceans.
  • Similar geological structures (rock layers in South Africa match those in Brazil)

• The shoreline shape of continents with similar geological features seem to fit like a jigsaw puzzle.

Theory of plate tectonics

suggests that lithosphere is broken
into sections called plate tectonics which move on top of mantle

Evidence of plate tectonics

• distribution of fossils

• geologic matching of rock formations

• jigsaw-like fit of continents

• paleomagnetic st

What are convection currents

movement of fluids or air based on density difference caused by differing temperatures

3 steps for formation of convection currents

1. As magma heats up its molecules spread out, becomes less dense, and rises above cooler magma

2. Near the asthenosphere magma cools and begins to sink

3. This forms a circular cell of molten rock capable of moving the lithosphere plate above it

Features at transform boundaries

• Earthquakes

• Tsunamis

Features at convergent boundary

• Trenches

• Volcanoes

Features at divergent boundary

• Earthquakes

• Ridges

• Hydrothermal vents

How do volcanoes form at convergent boundary (4 steps)

1. Plate subducts and is exposed to friction

2. This causes rock to melt

3. Melted rock is less dense and rises to surface

4. This forms volcanoes ob non-subducting plate

How do volcanoes form at divergent boundary (3 steps)

1. Crust pushes away from the ridge

2. This movement causes small cracks to form on ocean floor

3. Magma rises to surface through cracks and forms volcanoes

Explain the movement of two plates at convergent boundary

1. Oceanic plate subducts under the continental plate

2. Oceanic plate is more dense than continental plate

Compare oceanic and continental plate

• Oceanic plate is slimmer but more dense than continental plate

• Continental plate is thicker and made of granite

• Oceanic plate made of basalt

Steps for earthquakes to form

1. Energy is released from seabed

2. All water moves above seabed

3. Water holds onto energy and moves very quickly through deep water

4. Water gets to shallower water and slows down but height grows very tall

Steps for hydrothermal vents to form

1. Cold water seeps through cracks in thin crust surrounding divergent boundaries

2. Water flowing into a magma chamber dissolves mineral from rocks 

3. Super heated water coming from hydrothermal vents is under pressure, hot and rich in dissolved nutrients and this forms hydrothermal vent plume

4. Superheated water meets near freezing ocean floor and cools

5. Minerals precipitate out of solution (solidify and pile on top of each other)

6. This causes a vent/chimney for the water and can be 60m high

What is an abyssal plain

Flat, sandy region of the ocean floor found at transform boundaries or between boundaries

How do abyssal plains form

1. As new seafloor is formed the old rock is pushed further and further away

2. Over time the rocks are covered with sediment and organic material

What are paleomagnetic stripes/magnetic polarity reversal

• Measured the magnetism of the ocean using magnetometers

• Earths crust is laid out in alternating stripes of normal polarity and reversed polarity

• Evidence shows that striped pattern began at mid ocean ridges where crust is weakest and magma pushed through

Compare chemical and physical weathering in marine environments

• Chemical weathering changes the rock’s composition chemically

• Physical weathering breaks rocks into smaller pieces without chemical change

Characteristics of chemical weathering

• Caused by reactions with water and oxygen

• Releases dissolved minerals into the ocean

Characteristics of physical weathering

• Caused by temperature changes or wave action

• Increases sediment size and volume

Describe how sedimentation shapes muddy shores

• Muddy shores are found in protected areas with little wave or current action

• Fine sediments like silt settle out of suspension due to low water movement 

• Sedimentation is the main process responsible for the formation of muddy shore

Explain how deltas form at the mouths of rivers

1. Rivers pick up sediment as they flow downstream

2. As the river widens at the mouth, water slows down

3. Sediments settle to the bottom, forming sandbars

4. Over time, the buildup forms a fan shaped delta with possible tributary channels

Identify and describe two types of erosion and how they transport sediment

• Ice erosion: glaciers crush rock and transport sediment within or on top of the ice

• Water erosion: rivers and runoff carry sediment to the ocean

Explain how erosion and sedimentation work to form estuaries

• Estuaries are sheltered from strong wave action so very little erosion occurs

• The water is calm, allowing fine particles like silt and sand to settle (sedimentation) 

State two reasons why rock shores are resistant to erosion

• Made of granite which is resistant to weathering

• Open and exposed, but rocks are large and tightly packed

Explain how water erosion can contribute to sedimentation in marine environments

1. Water erosion picks up and carries sediments through rivers and runoff

2. As water slows (when it reaches ocean) sediments begin to settle

3. Larger particles settle first while finer particles may stay suspended and travel further

Identify the main processes involved in shaping sandy shores and describe how they affect the shoreline

• Wind and wave erosion: moves sand along the beach and up and down the shore

• Gradual slope forms due to loose sediment settling and constant motion

• These processes constantly shift and reshape the shoreline 

Compare estuaries and deltas in terms of their formation and environmental conditions

• Estuaries form where freshwater meets saltwater in partially enclosed body; deltas form where a river deposits sediment at its mouth

• Estuaries have brackish water and are sheltered from waves; deltas are more open and subject to sediment build up

• Estuaries are turbid and nutrient-rich due to fine sediments; deltas are shaped by sediment slowing and settling

Describe how sediment size and water speed affect deposition

• Faster-moving water can carry larger particles

• As water slows larger particles settle first

• Fine particles like silt can stay suspended longer and travel farther

Describe the 4 types of erosion

• Ice erosion: glaciers drag and crush rocks, carrying sediment embedded in ice

• Gravity erosion: rocks fall from cliffs and move toward the ocean

• Wind erosion: wind blows sand or dust from one place to another

• Water erosion: rivers and runoff carry sediment into the sea

Explain how the morphology of a rocky shore affects sedimentation

• Rocky shores are steep and made of resistant granite

• High wave energy removes loose particles before they settle

• As a result, very little sedimentation occurs on rocky shores

Explain how tides are produced

Tides are the periodic rise and fall of the surface of the ocean resulting from the gravitational interaction of the earth with the moon and sun

Identify and describe two types of tidal patterns

Semi-diurnal: tides that occur twice a day (two high and two low tides)

Diurnal: tide occurs once a day (one high and one low)

What is tidal range? What causes it? How is it calculated?

• Tidal range: difference in tide height between consecutive high and low tide

• Caused by gravitational pull of sun and moon and difference

• High tide - low tide = tidal range

Describe and explain what causes a spring tide to form and how often do they occur?

• Describe: spring tides occur when the earth, sun, and moon are aligned (new moon and full moon)

• Explain: the alignment amplifies the gravitational effect the moon and sun have on earth

• Spring tides occur twice a month

Describe and explain what causes neap tides to occur and how often do they occur?

• Describe: occur when the sun and moon are at right angles from each other

• Explain: sun and moon are pulling at opposite directions causing a smaller than average tidal range

• They occur twice a month

Describe how the alignment of sun, moon, and earth cause tidal range seen with spring tides

• tidal range = high tide - low tide

• When earth, moon, and sun are in straight line gravitational effects of sun and moon combine and cause stronger tides

• greater tidal range = spring tides

State 3 factors, other than gravitational effect on moon and sun, that could influence tidal range

• shape of coastline

• size of body of water

• weather conditions

Explain how the shape of the coastline could influence tidal range

• If the tide enters a narrow channel or bay the tidal height is increased because water is being forced into small area

• Along an ocean beach the tide height is not increased due to water being more spread out

Explain how weather could influence tidal range

• During tropical cyclones the air pressure is much lower and allows the water to swell; high winds also push water onto the shore

• High winds and low air pressure can create a tidal surge (rising water higher than the predicted level of the tide)

Define ocean currents

A continuous physical movement of water caused by wind or density

What are surface currents caused by

Surface currents are driven by wind (caused by uneven heating on earth’s surface)

What factors cause deep currents to form

Deep currents are driven by difference in density as temperature and salinity changes

Describe the Coriolis effect

• It is a result of earth’s rotation causing wind and objects to be deflected toward left or ight and now travel in straight pattern

• This also causes surface currents to be deflected at a 45-degree angle

Describe thermohaline circulation

1. Starts in N pole when cold water freezes to ice-leaving salt behind

2. Denser water down wells, mixed with water column until its at the bottom

3. In Antartica water gets colder and then splits

4. One current goes to Indian ocean and one current goes to pacific ocean

5. Water near equator warms/rises

6. Both warm currents go north in Atlantic towards the N pole

Describe the movement of surface currents in the northern and southern hemisphere

• Northern hemisphere currents have clockwise spiral

• Southern hemisphere currents have counter clockwise spiral

• As wind blows water across the ocean, the rotation of earth causes it to deflect at 45 degree angle (Coriolis effect)

Describe upwelling

• Movement of cold nutrient rich water from deep ocean to the surface

• Caused by warmer water being pushed away from the coastline causing low-pressure area that brings colder water to the surface

Describe the movement of surface water in the south pacific ocean during normal conditions

Winds-westerlies blow water away from south coast of South America and towards Australia and Asia

What is El Nino and where does it occur

El Nino is a warm current and it develops off the coast of Ecuador in December

Describe the effect La Nina has on upwelling compared to El Nino

• El Nino suppresses upwelling 

• La Nina allows for more cold water from Humboldt current to rise to the surface

• Stronger upwelling than normal more than average nutrients surface to the top of the ocean

• This leads to a greater ocean productivity

Explain the effect El Nino has on the fish harvest for fisherman in Eastern Pacific

• Reduction in upwelling of cold deep nutrient rich water off cost of Peru

• Less nutrients in water lowers phytoplankton productivity

• This will cause a reduction of food for sardines population and less sardines stock

• Weaker east pacific current causes an increase in temp of coastal waters and causes a decline in cold-water species

Explain why there’s a small fish harvest during El Nino years

• No upwelling

• Less nutrients for producers causing decline in phytoplankton

• This causes a decline in fish population

• Cold water fish cannot adapt to changes in water temp

• As upwelling is suppressed, warm water builds up at the surface of the ocean

Binomial nonmenclature

Universally recognized two-word name for a particular species

Genus

First part of binomial nonmenclature given the capital letter

Species

Second part of binomial nonmenclature given the lowercase letter

Levels of classification

• Domain — different kingdoms

• Kingdom — different phylum

• Phylum — different classes

• Class — similar orders

• Order — similar families

• Family — one of more similar genus

• Genus — one of more closely related species

• Species — unique to each organism within a genus

Dichotomous key

• System used to identify organisms

• Made up of pairs of contrasting descriptions

What are the 8 groups of marine organisms

• Phytoplankton

• Zooplankton

• Echinoderms

• Crustaceans

• Bony fish

• Cartilaginous fish

• Macroalgae

• Marine grasses

Plankton

Diverse collection of microscopic organisms that have limited mobility and drift in water currents

Why are plankton considered keystone species

They are indicative of the health of an ecosystem

Two groups plankton is divided in to

Phytoplankton (producers) and zooplankton (consumers)

Main types of phytoplankton

Diatoms and dinoflaggellates

Diatoms

• Unicellular

• Cell walls with silica

• Found in surface waters, reproduce rapidly

• Represent base of food web

• Consumed by krill

Dinoflagellates

• Unicellular

• No silica cell walls

• Found in surface water, reproduce rapidly

• Some produce toxins that can poison fish and accumulate in shellfish poisoning humans and other organisms

Zooplankton

• Consumers (including larvae, copepods, jellyfish)

• Migrate vertically in the water column each day to feed on phytoplankton

• Sensitive to environmental changes (pullution, microplastics, acidification, etc)

Larvae

Planktonic stage of fish and invertebrates like sea star (adapted to life floating in the ocean)

Copepods

• Most abundant and diverse group of zooplankton

• Are crustaceans, herbivores,, feed on diatoms

• Bodies are divided (head, thorax, abdomen, two antennae, 2-4 pairs of appendices extend thorax)

• Exoskelton made of calcium carbonate and have spikes for protection and better floatation