ch 8

Point source.

A single identifiable source of pollution

Four types of Hard Stabilization

Groin, Jetty, Seawall, Breakwater

Constructive Waves

Has low wave height and long wave length with low frequency Small oceans with small fetch It builds the beach up

Why does the wave height of a tsunami increase as the tsunami enters shallow water?

In shallow water, the energy of the tsunami must be contained within a smaller water column.

Destructive Waves

It removes material from the beach Large oceans with large fetch produce large waves

What is one of the best ways to recognize a rip current as viewed from above?

Look for turbid water caused by suspended sediment within the rip current.

Describe estuarine circulation.

Low salinity surface water moves toward the mouth and denser, higher salinity water at depth moves toward the head

Barrier Island

Made of sand or sediment that lay parallel of mainland coastline. They provide coastline habitats for species. They block storms from destroying the mainland.

Does the med exhibit estuarine circulation

No

Which ocean is associated with most tsunamis?

Pacific Ocean

Non-point source pollution.

Pollution that comes from many different sources.

Seawalls

Purpose=armor the coastline and protect landward developments from ocean waves. sediment is eroded on a seaward side, may eventually collapse! (Wave reflection off of the wall). Erosion at base accelerates.

What is biomagnification?

The higher in the food chain.

How does the tide cycle affect erosion along a sea coast?

The tide cycle causes erosion to occur at different elevations along a sea coast.

What causes waves to refract as they approach the shore?

The wave base begins to touch the sea floor. They transition from deep-water waves to shallow-water waves.

What triggers a wave traveling across the ocean to finally release its energy?

The wave begins to interact with the sea floor as it moves into shallower water.

Will Sumatra experience another tsunami like the destructive one of December 2004?

This is likely, because Sumatra is near many ocean trenches.

What is bioaccumulation?

Toxins accumulate in the tissues.

Why do ships at sea tend not to notice tsunamis?

Tsunamis in deep water have small wave height and long wavelength.

How do rip currents form?

Water builds up at the beach face and then moves away from shore in narrow currents.

How is a cave created in a cliff face along a sea coast?

Wave action erodes areas of weakness in rock in a sea cliff.

Backwash

Wave pulls back into the sea

Swash

When a wave rolls and breaks on the beach

What caused the Indian Ocean tsunami of 2004?

a 9.2-magnitude earthquake off the coast of Indonesia in the Java Trench

What is a tsunami?

a a seismic sea wave and a shallow-water wave caused by displacement of the water column

What is a tsunami?

a series of water waves that travel away from a fault in all directions at high speed

Groin

built perpendicular to a coastline and are specifically designed to trap sand moving along the coast in longshore transport (rip rap, upcoast slide)

What type of plate boundary are most tsunamis associated with?

convergent plate boundaries

Four estuary types by geologic origin.

costal plain, fjord, bar-built, tectonic

What type of feature is a barrier island?

depositional

Four types of coastal waters.

estuary, coastal wetland, lagoon, marginal sea

Which of the following best describes a plunging breaker?

forms on moderately sloped shorelines to create curling crests

The two most specific groupings in taxonomic classification are __________.

genus and species

Know linnean classification scheme.

kingdom, phylum, class, order, family, genus, and species

What is the movement of sand down the beach called?

longshore transport, river of sand, longshore drift

What is a typical tsunami wavelength?

more than 200 kilometers

Breakwater

parallel to shoreline. provide safe anchorage to ships. interrupts river of sand (sandbar) dredging to unclog. (Santa Barbara, California)

Jetty

perpendicular. purpose=to protect harbor entrances from waves and only secondarily does it trap sand. (causes more upcoast deposition and downcoast erosion)

Four estuary types by geologic circulation.

salt wedge, partially mixed, well mixed, fjords

What disturbing force is responsible for most ocean waves that eventually break on shore?

storm-generated winds that blow across the surface

What type of breaker would pose the most danger to people playing or swimming in the surf zone?

surging breakers

What causes the three different types of breakers?

the steepness of the beach slope

How are tsunamis generated?

through displacement of the seafloor under water

What determines the speed of shallow-water waves?

water depth

What causes longshore transport?

wave refraction

What determines the speed of deep-water waves?

wavelength

How does a sea stack form?

when a sea arch collapses, leaving a vertical column of rock offshore.

How is an arch formed along a sea coast?

when a sea cave breaks through a headland or where two sea caves coalesce as they erode back due to wave action