Dynamic Earth Test

Question 1

*Our understanding of the earth’s interior is based entirely on the study of ______ _______. Be sure to understand and know how to use page 10 of the ESRTs, the inferred properties of the earth’s interior.

Answer 1

earthquake waves

Question 2

Answer 2

understand

Question 3

what did the idea of continental drift suggest?

Answer 3

Suggested that the continents have been moving across the earth’s surface for millions of years.

• Suggested that continents were once together in a super-
  continent called Pangaea about 250 million years ago

Question 4

Evidence for continental drift

Answer 4

✴ The apparent fit of the continents
✴ Fossil correlation
✴ Rock/Mountain correlation
✴ Paleoclimate data (coal in
Antarctica, Glaciers in the tropics)

Question 5

Wegener’s theory was _______ because he failed to explain
what _______ was driving the ______.

Answer 5

rejected

force

motion

Question 6

Plate tectonics is a

Answer 6

Theory developed in the mid-1900’s that explained all geologic observations including mountains, earth-quakes, volcanoes, and trenches

Question 7

How do plate tectonics move?

Answer 7

The lithosphere of the earth is broken up into plates which “float”
on the plastic asthenosphere below

Convection currents in the asthenosphere move the plates around

Question 8

Plates interact with each other in three ways:

Answer 8

✴ Move towards each other (CONVERGENT)
✴ Move away from each other (DIVERGENT)
✴ Slide past one another (TRANSFORM)

Question 9

Subduction zone (_________ crust and ________ crust)

Answer 9

continental, oceanic

Oceanic crust is forced down because it’s more dense

Volcanoes, mountains, earthquakes and trenches are common
Example: Western South America

Question 10

Collision zone (________ crust and ________ crust)

Answer 10

continental, continental

Both plates have the same density and therefore crumple up as they collide

Mountains and earthquakes are common

Example: Himalayas

Question 11

TRANSFORM PLATE BOUNDARIES

Answer 11

Two plates slide laterally past one another
Earthquakes are common as friction and pressure builds up
Example: San Andreas Fault

Question 12

Island Arc (_______ crust and _______ crust)

Answer 12

oceanic, oceanic

Two oceanic plates collide and one usually subduct under the other

Volcanic islands, earthquakes and trenches are common

Example: Aleutian Islands

Question 13

DIVERGENT PLATE BOUNDARIES

Answer 13

Two plates move away from one another
Magma rises at the boundary forming a ridge with a valley and new sea-floor
Alternating bands of magnetic polarity are locked in the sea-floor
Sea-floor rock gets increasing older as you move away from the boundary
Example: Mid-Atlantic Ridge

Question 14

*HOT SPOTS

Answer 14

There are locations on earth, away from plate boundaries, where volcanic activity occurs

Magma rises from the mantle and forces its way through the lithosphere, forming a chain of volcanoes.

Example: Hawaii

Question 15

DEFORMATION

Answer 15

When plates interact, rocks are exposed to intense pressure which cause deformation

Question 16

Rock layers are always laid down _______; if they are observed in any other position, you can infer that
_______ has taken place

Answer 16

horizontally, deformation

Question 17

The discovery of marine fossils high in mountains is evidence for _____ _____

Answer 17

crustal uplift

Question 18

Major types of deformation include ________, ________, and ________

Answer 18

folds, faults, tilts

Question 19

P-Waves

Answer 19

P-Waves
* Move fast
* Can travel through liquid and solid
* Push-pull motion

Question 20

S-Waves

Answer 20

S-Wave
* Move slow
* Can only travel through solids
* Shear wave motion

Question 21

The focus is -

Answer 21

The spot within the Earth where an earthquake begins.

Question 22

Epicenter-

Answer 22

The spot on the surface of the Earth closest to the focus.

Question 23

Fault-

Answer 23

Crack along which movement takes place.

Question 24

Graphing foci depth can reveal the type of _____ _________.

Answer 24

plate boundary

Question 25

Foci will get _______ as you travel along a _________ _____

Answer 25

deeper, subducting plate

Question 26

Shadow Zone-

Answer 26

An area on the opposite side of the Earth from where an earthquake happens that receives no earth-
quake waves because of refraction of P-waves and absorption of S-Waves into the liquid outer core.

Question 27

Finding Epicenter Distance

Answer 27

1. Determine the difference in arrival time between the P and S waves
2. Line a piece of scrap paper along the vertical axis of the reference table
   and mark of the location of zero and the difference in arrival time
3. Slide the paper along the curve until the marks match up perfectly with
   the P and S curves
4. Follow the paper down to the horizontal axis and read the epicenter distance (it is in thousands!)

Question 28

Finding Travel Time

Answer 28

1. Find the epicenter distance for the station using the horizontal axis of the
   reference table
2. Go up to the P or S curve (depending on what you are looking for)
3. When you hit the curve, go to the left and read the time off the vertical
   axis

Question 29

Locating the Epicenter Location

Answer 29

1. Determine the epicenter distance for three different seismograph location (seismic stations)
2. On a map, draw a circle with a radius of the epicenter distance around each seismic station
3. At the location where the three circles intersect is where the epicenter of the earthquake was located

Question 30

REMEMBER: TO FIND THE LOCATION OF THE EPICENTER, WE MUST HAVE DATA FROM ______ DIFFERENT SEISMIC STATIONS

Answer 30

THREE

Question 31

Don’t forget to study the reference tables!!!

Question 32

The Richter scale is used to determine what?

Answer 32

How powerful a quake is. It is used to determine an earthquakes strength. It uses numbers to measure the severity of an earthquake.