MRSC 100 Exam 3

What are the main differences between the coastal ocean and the open ocean?

The coastal ocean is shallower, more productive, and rich in biodiversity, supporting various ecosystems like coral reefs and mangroves. In contrast, the open ocean is deeper, covers a larger area, has lower nutrient levels, and is less biologically productive, often described as an ocean desert.

What are the primary causes of sea level change?

Thermal expansion of seawater and melting ice (particularly ice on land)

How are sea levels predicted to change this century?

Up to 4 feet

What are the differences between erosional and depositional (or emergent and submergent) coastlines?

Erosional coastlines are characterized by the removal of sediment, often featuring rocky cliffs and high-energy wave action, while depositional coastlines accumulate sediment, creating features like beaches and barrier islands.

What are features of erosional (emergent) coastlines?

typically feature cliffs, wave-cut platforms, sea caves, sea arches, and sea stacks, which are formed by the action of waves eroding the land.

What are features of depositional (submergent) coastlines?

include irregular shorelines, estuaries formed from drowned river mouths, and landforms such as spits, baymouth bars, and barrier islands. These coastlines are typically created by rising sea levels or land subsidence, leading to the flooding of coastal areas.

What are the 4 main parts of a beach?

Backshore: where waves come in at highest tides; sediment build up (berms)

Foreshore: where waves are breaking

Nearshore: where waves form

Offshore: deep waters

Identify the source material and probable wave energy associated with: a relatively steep

beach made of pebbles; and a very slow sloped tropical white-sand beach.

Steep beach made of pebbles: high wave energy removing all small grains of sand

Sloped tropical white sand beach: sloped means NOT high waves so the sand isn't pulled out further into the ocean

parrot fish chop up coral and

poop it out which creates the sand

How do seasonal changes typically affect sandy beaches?

In winter, high-energy storm waves pull sand offshore, leading to narrower beaches, while in summer, gentler waves push sand back onto the beach, widening it and restoring its sandy profile.

How does a rip current form?

created by water being forced between sand bars. Path of least resistance.

What's the easiest way to get out of a rip current?

Swim perpendicular to the current

After a half hour of body surfing at Huntington Beach, you find that you are pretty far from

where you left your towel. What is responsible for this? How does this process move materials down the beach?

Longshore currents move at an angle

How do sand spits form?

through a process called longshore drift, where waves approach the beach at an angle, moving sediment along the coastline

how do baymouth bars form?

Baymouth bars form when sediment is deposited by longshore currents, creating a sandy barrier that extends across a bay, partially or completely closing it off.

How do tombolos form?

The spit continues to grow until it connects the mainland and an island (like a bridge)

Where does our local sand come from?

California mountain ranges erode and the sediments are washed down rivers

Why do some beaches have a lot of sand but nearby ones have very little? What must be in between them?

There may be an island or land jetting out blocking the flow of sediment to the beach.

What effect do seawalls, jetties, groins, breakwaters, beach nourishment, and land reclamation have on coastal shores?

Seawalls- They're parallel to shore and make beaches thinner because of an increase of erosion, eventually the beach is completely eroded.

Jetties- Perpendicular to the shore; open up to harbors; erodes one side, and deposits sand on the other.

Groins- Perpendicular to shore; a big field of jetties that erode and deposit (doesn't open up to a harbor).

Breakwaters- Parallel to shore; creates tombolos because it reduces wave action

Beach Nourishment- (Brings sand back to the beach by dredging offshore

- Doesn't always stay

- Must be the SAME type of sand that's already there)

Land Reclamation- Creating new land but needs to be rebuilt over and over again because sand is constantly moving

What is a marine terrace? How are they formed?

Marine terraces are formed through a combination of wave erosion and tectonic uplift. High wave energy creates a wave-cut platform, which can become a terrace when the land is uplifted above sea level, often due to tectonic movements or changes in global sea levels.

Explain how wave energy affects headlands and bays differently. How do they look different from each other? Why is this?

high wave energy = rocky sand, brings bigger rocks up and on its way back it brings the smaller stuff back into the ocean, steeper slope with more energy

Low wave energy = finer sand, can't bring up big rocks, coral reef causes waves to break there causing low energy wave in the lagoon

how is a sea cave formed?

Sea caves form when waves cut large holes into fractured or weak rock along the base of sea cliffs

How is a sea stack formed?

A cave that had been eroded by waves continues to erode into an arch, and when that arch collapses it is left as a pillar of rock.

How is a sea arch formed?

A sea arch is formed through the erosion of rock by waves, which create sea caves on either side of a headland. Over time, these caves can merge to form an arch

Identify and describe the characteristics of the 4 major types of estuaries. Explain why they

each have the characteristics that they do.

drowned river valley: a coastal area where a river valley has been flooded by rising sea levels, creating a mix of fresh and saltwater. Rich in biodiversity.

bar-built: coastal body of water that is partially enclosed by sandbars or barrier islands, which protect it from the open ocean.

tectonic: formed by the movement of the Earth's crust, which can create depressions or basins that fill with seawater.

fjords: where freshwater from glaciers meets and mixes with saltwater from the ocean, typically characterized by steep cliffs and deep, narrow inlets.

why do many deltas have the characteristic patterns of sediments

deposition that they do?

due to the interaction between river flow and the body of water they enter, which slows down the river's current and causes sediment to settle out. The shape and structure of a delta are influenced by factors such as sediment type, water velocity, and the frequency of changes in the river's course, leading to various forms like triangular or fan shapes.

How do fringing reefs, barrier reefs, and atolls form?

The most common type of reef is the fringing reef. This type of reef grows seaward directly from the shore. They form borders along the shoreline and surrounding islands.

When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center.

Barrier reefs are similar to fringing reefs in that they also border a shoreline; however, instead of growing directly out from the shore, they are separated from land by an expanse of water. This creates a lagoon of open, often deep water between the reef and the shore.

Describe how mangroves are able to often create new coasts (islands or extend coastlines)?

Mangrove forests reduce waves and increase sedimentation.

What are the properties of living organisms?

1. multicellular w/ complex structure

2. must acquire,transform,store, and use energy

3. respond to internal/external stimulus

4. maintain homeostasis

5. store, use, and transmit energy

6. reproduce, develop, grow, and die

7. possess emergent properties that can't be predicted from sum of parts

8. must adapt and evolve

Why is it possible that life could have originally began (or at least "grew up") in the ocean?

Early organisms lived in the ocean because there was no oxygen in the early atmosphere, and therefore there was no ozone layer to block harmful uv rays so the earth was extremily hot

How does a population of organisms modify their collective traits over time to adapt to a new or changing environment? Explain the process.

natural selection. one organism doesn't adapt, populations that are successful will weed out unsatisfactory traits overtime keeping the successful ones, always at the hands of avoiding predation or illness and death in general. these traits are then passed down and continue to develop over time

How can a single-species population eventually lead to two populations of separate species?

a process called speciation, which often occurs when populations become isolated from each other, either geographically or through other barriers that prevent interbreeding. Over time, these isolated populations may evolve different traits and reproductive barriers, making it impossible for them to mate successfully, thus forming distinct species.

When are similar types of animals officially considered to be two different species?

When they cannot interbreed fertile offspring

What effect do mass extinctions have on the evolution of species all around the globe?

Adaptive radiation = big event/ extinction = evolution is kickstarted/ happens rapidly =gives new niches to other oraganisms to move in to the extincted animals living space, can feed off there food etc

How do we name and categorize living organisms?

Taxonomy: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Describe the three general lifestyles that most marine organisms fit into.

autotrophs, which produce their own food through photosynthesis or chemosynthesis; heterotrophs, which consume other organisms for energy; and decomposers, which break down dead organic material and recycle nutrients back into the ecosystem.

Explain the potential strategies that bioluminescence may serve.

attracting mates, luring prey, camouflage, and deterring predators

What is the difference between waves and currents? What happens to an individual water molecule in each case?

Waves moves energy through water and currents and move water. In a wave an individual water molecule moves in a orbital pattern, while in a current the water molecule moves from place to place

What are the parts of a wave?

crest: highest part

trough: lowest part

amplitude: how far the wave moves from its center line to its crest or trough.

wavelength: how far between each crest or trough

what is the period and frequency of a wave?

Period: time required for a wave to move one wavelength

Frequency: number of waves passing a fixed point per second

Explain the differences between capillary waves and gravity waves. What are some examples of both disturbing and restoring forces in each of these types of waves?

Capillary = (waves with wavelengths less than 1.73 centimeters ) Restoring force = cohesion (sticking together) of water molecules (hydrogen bonds create surface tension)

Gravity waves= (waves with wavelengths more than 1.73 cenitmeters ) depend on gravity for the restoring force, the gravity pulls the crest downward but the intertia of the water causes the crests to overshoot and become troughs = causes circular motion

What happens to an object floating on the surface as waves go by? Explain why it follows the path that it does.

The object moves in a circular motion and does not move; The wave travels through inertia but the water does not.

What factors are important in increasing the amount of energy that a wave has in the open ocean?

Wind speed, the duration of wind blowing over the water, the distance over which the wind travels (fetch)

Explain why one of Hawaii's coasts gets huge waves during part of the year, but not all year. Be sure to specify which coast and what time of year.

The north shore of Oahu has a lot of big waves in the winter from the storms up in the north like Alaska (storms send big swells). During the summer, there are no storms in Alaska so no large waves form. In between Alaska and hawaii there is a lot of energy for wind duration, a lot of fetch, and speed

Explain why waves are generally poorly shaped during a local storm, but typically arrive on a beach in orderly sets from a storm far out to sea.

Time and distance. Constructive and destructive waves. The storm is quick and destructive (not enough time), the storm out at sea has time to build.

how do rogue waves form?

when smaller waves interact and combine due to various ocean dynamics, such as differing wave speeds and directions, creating a single large wave

Why do waves tend to arrive at the coast in sets? Why aren't they all the same size?

Waves arrive at the coast in sets due to the grouping of swells created by wind patterns over large distances. They vary in size because waves of different periods tend to group together, with larger waves often being the result of a reorganization of these long-distance swells.

What are wave windows? Why do particular beaches tend to get better surf at different times of the year?

A path of waves that hit a coastline. Winter waves north form west from Alaska. Summer waves form south from tropical storms and winter in the southern hemisphere.

What factors control the speeds of deep water waves, shallow-water waves, and intermediate waves? Explain why?

The longer the wavelength, the faster the wave will move through the water. The speed of all waves is controlled by gravity, water depth, and wavelength.

How does a wave break when it gets close to shore? Explain the process.

As waves reach the shore, the energy in front of the wave slows down due to friction with the shallow bottom, and the wave breaks.

What are the primary types of breaking waves, and what can they tell us about the shape of the underwater landscape/slope at a particular beach?

Spilling waves: gradual sea floor slope.

Plunging waves: steep seafloor slope.

What is the difference between wave refraction, wave defraction, and wave reflection?

Wave reflection occurs when a wave bounces off a surface, following the law that the angle of incidence equals the angle of reflection. Wave refraction is the bending of a wave as it passes from one medium to another, while wave diffraction involves the spreading of waves as they pass around obstacles or through openings.

How are internal waves similar and different from surface waves?

Internal waves and surface waves are both types of gravity waves. Internal waves occur within the ocean's layers, and are influenced by density differences, while surface waves travel along the surface of the water and are typically more visible and affected by wind.

How can we typically identify internal waves from the surface? Why are they important?

Internal waves can often be identified from the surface by observing slick bands of smooth water alternating with rough patches, which indicate the presence of these waves below. They are important because they help transfer heat, energy, and nutrients in the ocean, playing a crucial role in maintaining a healthy marine ecosystem.

what is storm surge and what causes it?

Storm surge is the abnormal rise in sea level that occurs during storms, primarily due to strong winds pushing water toward the shore.

In what ways are seiches different from surface waves? How are they formed?

Seiches are standing waves that move back and forth. Usually occur in enclosed or partially enclosed bodies of water like harbors and bays, while surface waves are typically generated by wind and move across the surface of larger bodies of water. Seiches are formed through resonances caused by disturbances such as wind, atmospheric pressure changes, or seismic activity (earthquakes)

What causes a tsunami? How are the characteristics, movement and appearance of these waves different from ocean surface waves?

Tsunamis are primarily caused by the displacement of a large volume of water due to underwater earthquakes, volcanic eruptions, or landslides. Unlike regular ocean waves, which are generated by wind and have energy confined to the surface, tsunamis have energy that extends throughout the entire water column, allowing them to travel at much higher speeds and appear as a rapidly rising tide rather than breaking waves.

What is a free wave?

a wave that propagates across the sea surface without the further influence of the force that formed it

What is a forced wave?

A wave maintained by its disturbing force. For example tides are dependent on the gravitational pull of the moon and sun.

What is an orbital wave?

a wave in which particles of the water move in closed circles as the wave passes

What is a progressive wave?

A wave that carries energy from one place to another without transferring any material.

What causes the tidal bulges on either side of our planet? Does the sun or moon have a bigger effect on the tides? Explain why.

Tidal bulges are caused by the gravity of the moon. The moon has a larger effect on the tides because the center of mass is closer than the sun.

Explain why a tidal day is 50 minutes longer than a normal day

During 24 hrs it takes Earth to make full rotation, Moon has continued moving another 12.2 degrees to east in orbit around Earth

= Earth must rotate an additional 50 min to "catch up" to moon so that it's directly overhead (meridian)

What is the difference between a sidreal and sydonic month

A sidereal month is about 27.3 days and measures the time it takes for the Moon to complete one full orbit around the Earth relative to the stars. In contrast, a synodic month lasts about 29.5 days and is the time it takes for the Moon to go through all its phases, from one new moon to the next.

what is the difference between a spring and neap tide?

A neap tide is when the daily tidal range is the smallest. A spring tide is when the daily tidal range is the largest.

What happens to the moon, earth, and sun during a spring or neap tide?

During spring tides, the moon, earth, and sun are aligned in a straight line, resulting in higher high tides and lower low tides due to the combined gravitational pull of the moon and sun. In contrast, during neap tides, the moon and sun form a right angle with the earth, which partially cancels out their gravitational effects, leading to lower high tides and higher low tides.

How does the dynamic model of tides differ from the equilibrium model of tides? Which is more accurate for predicting our tides?

The dynamic theory of tides takes into account the effect of continents, shallow water, and partially enclosed ocean basins on tide formation.The equilibrium theory of tides deals with the position and attraction of the Earth, moon and sun to explain why tides occur.

What are the three main tide patterns? Explain how they are created. Why do they generally occur in different geographic areas?

Semi-diurnal: 2 high/2 low

Mixed-diurnal: 1 high high tide, 1 low high tide, 1 high low tide, 1 lower low tide

Mixed-semi-diurnal: 2 tides (2

high/low but at different heights)

Diurnal: 1 high and 1 low tide

How are flood currents and ebb currents different from each other?

Flood currents occur when water moves toward the land during high tide, while ebb currents happen when water flows back to the sea during low tide.

What are examples of true tidal waves?

tidal bores, which occur when a strong tide pushes up a river against its current