Final Flashcards
seismology
The study of earthquakes
elastic rebound
The sudden return of elastically deformed rock to its undeformed shape
Richter Scale
Used to measure the strength of earthquakes with magnitude
Mercalli Scale
Used to measure earthquakes using intensity
deformation
The bending, tilting, and breaking of the Earth’s crust; the change in the shape of rock in response to stress
seismic waves
A wave of energy that travels through the Earth, away from an earthquake in all directions
earthquake hazard
The measurement of how likely an area is to have damaging earthquakes in the future
seismograph
An instrument that records vibrations in the ground and determines the location and strength of an earthquake
retrofitting
The process of making older structures more earthquake resistant
Where would you find both the epicenter and the focus of an earthquake?
The point on the Earth’s surface directly above an earthquake’s starting point, the focus, The focus is the point along a fault at which at the first motion of an earthquake occurs
P waves
P waves (primary waves) can travel through solids, liquids, and gases. They are first detected waves of an earthquake to be detected. They cause the particles of rock to move in a back-and-forth motion
S waves
S waves (shear waves) cannot travel through parts of the Earth that are completely liquid. They are the second-fastest seismic waves to be detected. They cause the particles of rock to move in a side-to-side motion
Earthquake safety rules
Indoors- Crouch or lie face down under a table or desk in the center of the room
Outdoors- Lie face down away from buildings
In a car- Stop the car and remain inside
volcano
A vent or fissure in the Earth’s surface through which magma and gases are expelled
hot spots
A volcanically active area of the Earth’s surface far from a tectonic plate boundary
magma
Molten rock
caldera
A large, semicircular depression that forms when the magma chamber below a volcano partially empties and causes the ground above to sink
crater
A funnel-shaped pit near the top of the central vent of a volcano
viscosity
The consistency of lava (low = runny & high = thick)
Where do volcanoes usually form?
Most volcanoes form on tectonic plate boundaries because this is where magma forms and rises to the surface
What factors are considered when predicting volcanic eruptions?
The frequency and type of earthquakes associated with the volcano as well as the changes in slope, changes in the gases released, and changes in the volcano’s surface temperature
volcanic blocks
largest pieces of pyroclastic material and are pieces of solid rock erupted from a volcano
volcanic bombs
large blobs of magma that harden in the air
lapilli
pebblelike bits of magma that hardened before they hit the ground
volcanic ash
makes up most of the pyroclastic material in an explosion, and forms when the gases in stiff magma expand rapidly and the walls of the gas bubbles explode into tiny, glasslike silvers
Active volcano
currently erupting or show signs of erupting in the near future
Dormant volcano
are currently not erupting, but the record of past eruptions suggests that they may erupt again
Extinct volcano
have not erupted in recorded history and probably never
will erupt again
What two forms can magma take when it erupts from a volcano
pyroclastic flow or lava
Pacific Ocean
Largest and flows between Asia and the Americas
Atlantic Ocean
Second largest and the volume is 1/2 of the Pacific ocean; borders NJ coastline
Indian Ocean
Third largest and is bordered by Asia on the North, on the west by Africa, on the east by Australia, and on the south by Antarctica
Southern Ocean
Fourth largest and extends from the coast of Antarctica to 60 degrees latitude
Arctic Ocean
Smallest ocean and most of the surface is covered with ice
What does Sonar stand for?
Sound, Navigation, Ranging
continental shelf
The gently sloping section of the continental margin located between the shoreline and the continental slope
continental slope
The steeply inclined section of the continental margin located between the continental rise and the continental shelf
continental rise
The gently sloping section of the continental margin located between the continental slope and the abyssal plain
abyssal plain
A large, flat, almost level area of the deep-ocean basin
mid-ocean ridge
A long, undersea mountain chain that forms along the floor of major oceans
rift valley
A long, narrow valley that forms as tectonic plates separate
seamount
A submerged mountain on the ocean floor that is at least 1,000 cm high and that has a volcanic origin
ocean trench
A steep, long depression in the deep seafloor that is parallel to a chain of volcanic islands or a continental margin
plankton
microscopic organisms that drift or freely near the ocean surface
nekton
animals that swim actively in the open ocean (dolphins, whales, crabs, and sea lions)
benthos
the organisms that live at the bottom of the sea or ocean (crabs, starfish, coral, sponges, seaweed)
living resources
fish, seaweed, kelp
non-living resources
oil, natural gas, sea-floor minerals, tidal energy, and wave energy
seaweed
species of algae
overfishing
taking more fish than can be naturally replaced
nonrenewable resources
resources that cannot be replenished
desalination
removal of salt from ocean water
renewable resources
resources that can be replenished
What is tidal energy generated from?
the natural movement of tides
What is wave energy?
a clean, renewable resource
Why are drift nets a problem?
They can accidentally catch dolphins and turtles
Why do engineers drill in the ocean floor?
to get oil and natural gas
Examples of Non-point source pollution
oil and gasoline that has leaked from cars, thousands of watercraft, such as boats and personal watercraft, pesticides, herbicides, and fertilizer from residential lawns and golf courses
Examples of Point-source pollution
oil tankers, waste treatment plants, factories
trash dumping
trash dumped in the ocean
sludge dumping
raw sewage flushed down toilets into the ocean
oil spills
oil dumped in the ocean
trash dumping examples
bandages, vials of blood, and syringes from hospitals
trash dumping effects
it can affect the organisms that live in the ocean and those organisms that depend on the ocean for food; Marine animals can mistake plastic materials for food and choke or become strangled
sludge dumping effects
can pollute beaches and kill marine life
how oil spills in the ocean
because oil is in such high demand across the world, large tankers must transport billions of barrels of it across the oceans; If not handled properly, these transports can turn disastrous and cause oil spills
effects of oil spills
they can harm plants, animals, and people, they are responsible for 5% of oil pollution in the ocean; Most of the oil that pollutes the oceans is caused by non-point source pollution on land from cities and towns
preventing oil spills
tankers are being built with two hulls instead of one; the inner hull prevents oil from spilling into the ocean if the outer hull of the ship is damaged
What is adopt-a-beach?
when people volunteer to clean up the beach
clean water act
put the EPA in charge of issuing permits for any dumping of trash into the ocean
U.S marine protection, research, and sanctuaries act
prohibits the dumping of any material that would affect human health or welfare, the marine environment or ecosystems, or businesses that depend on the ocean
