Oceanography Ch.2 Test

The name of the supercontinent

Pangaea

the superocean that existed with the supercontinent

Panthalassa

This is formed when two continental plates are divergent:

Rift Valley

The name of a continental transform fault found in southern California

San Andreas fault

Underwater volcanoes with a cone shaped (pointy) top are called:

Seamount

Where would you find the oldest oceanic crust

Subduction zone

Underwater flat-topped volcanoes are called:

Tablemount

Something you would find at a convergent plate boundary on the ocean floor

Trenches

Who came up with idea of continental drift

Wegener

T/F : Earthquakes are common along fracture zones.

False

T/F : New crust is formed at trenches and old crust is subducted at ridges.

False

T/F : Paleomagnetism confirms that, at particular times in the geologic past, Earth has had more than one magnetic north pole.

False

T/F : The magnetic field of the Earth reverses itself each time magma erupts at a mid-ocean ridge.

False

T/F : The magnetic north pole has remained very close to the geographic North Pole through all of geologic time.

False

T/F : The oldest rocks are located at mid-ocean ridges.

False

Two types of evidence that support continental drift

Fossils and glaciers

What scientists modeled the striping of the sea floor

Frederic Vine and Drummen Matthews

What are the three stages of reef development

Fringing, Barrier and Atolls

Name something (a place) created by a hotspot

Hawaii

Who wrote the Origin of Ocean Bases

Hess

What part of the ocean floor would you find new ocean crust being created?

Mid-Ocean ridge

what two things are formed from an ocean-continent convergent plate boundary

Mountain/volcanic range, trenches

What type of structures would you find at a continent convergent boundary?

Mountains

What structure would you find on the opposite side of the subduction done

Mountains (into a continent) Island arcs (into oceanic crust)

The mid-Atlantic ridge is an example of:

a divergent plate boundary

The study of changes in the character of oceans due to geographic changes

paleoceanography

The study of magnetism over geologic time

paleomagnetism

A depression along ridge axis is called a

rift valley

All continents fit together with the least number of overlaps and gaps when the continents are matched along:

contours at around 2000 meters in depth.

Island arcs are formed by:

convergent plate boundaries

Oceanic trenches are formed by:

convergent plate boundaries

Multiple Choice: Which of the following is associated with divergent plate boundaries on the seafloor?

crest of the mid-ocean ridge

Differences in height between continental crust and oceanic crust are explained by:

isostasy

Climate distribution on Earth is primarily controlled by:

latitude

Tectonic plates are actually peices of __________ floating on ___________

lithosphere on asthenosphere

How long ago did Pangea exist?

200 million years ago

At what type of plate boundary would you find shallow-depth earthquakes

Divergent

What two structures form from an ocean-ocean convergent plate boundary

Islands/volcanoes and trenches

Multiple Choice: Which of the following statements is true of the asthenosphere?

The asthenosphere is composed of outer mantle material.

Multiple Choice: Which of the following statements is true of the lithosphere?

The lithosphere is composed of the crust and the topmost portion of the outer mantle

Multiple Choice : Which of the following statements best describes the relationship between Earth's geographic and magnetic poles?

The magnetic pole wobbles, but stays near the geographic pole.

T/F : At divergent plate boundaries, only shallow focus earthquakes can be found.

True

T/F : Deep focus earthquakes are often associated with deep-sea trenches.

True

T/F : Deep-sea trenches are found at convergent plate boundaries.

True

T/F : Fast-moving spreading ridges tend to be more gently sloped than slow-moving ridges.

True

T/F : The relatively young age of the seafloor supports the idea that subduction must take place.

True

When does the Earth's magnetic field get reversed

about every 200,000-500,000 years - we don't really know for sure

Multiple choice: Fossils found in sediments can be used to...

all of the above

Multiple Choice : Which of the following is characteristic of oceanic-continental convergent plate boundaries?

andesitic volcanoes

Mountains are formed by:

both convergent & divergent plate boundaries

Volcanoes are formed by:

both convergent plate & divergent plate boundaries

The Mid-Atlantic Ridge is an example of a:

divergent boundary

Hydrothermal vents are formed by:

divergent plate boundaries

Rift valleys are formed by:

divergent plate boundaries

All the following provide evidence for continental drift except:

evidence of constant ocean salinity.

Areas of volcanic activity that remain in the same location over a long period of time and are not related to plate tectonics are called...

hotspots

Word Analysis : Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

hydrothermal vents, Hawaiian Islands, oceanic trench, Panamerica

Does water depth increase or decrease as you move away from the Mid-Atlantic ridge?

increase

Moving from oceanic ridge to oceanic trench, the thickness of the lithosphere:

increases in proportion to the distance.

The Hawaiian Islands are located where the Pacific plate is:

moving over a hot spot.

The seafloor magnetic pattern is be best described as:

parallel to and symmetric about ocean ridges.

Continental drift was confirmed through the study of the:

pattern of alternating magnetic polarity of seafloor rocks.

Deep ocean trenches are associated with:

subduction zones

Iceland is a geologically active area because its located over...

the Mid-Atlantic ridge

Confirmation of seafloor spreading was supported by:

the age of the seafloor

Vine and Matthews determined that new ocean floor was being produced at ocean ridges by examining:

the magnetic pattern on the seafloor.

Fossils of ancient polar plants are currently found near the equator because:

the plants lived near the poles, but since the n the continents have drifted to current locations

Oceans become deeper moving away from ridges due to:

thermal contraction of hot lithosphere.

Multiple Choice: Which of the following is characteristic of oceanic-oceanic convergent plate boundaries?

volcanic island arcs