geophysics earth structure

Question 1

Types of crusts

Answer 1

1. Continental crust
2. Oceanic crust

Question 2

Thickness of Oceanic Crust and Continental Crust

Answer 2

Oceanic : 7km
Continental : 35 km (Up to 70
km beneath Himalayas)

Question 3

Composition of Oceanic Crust and Continental Crust.

Answer 3

Composition of Oceanic : Basaltic
Continental : granodiorite

Question 4

Density of Oceanic Crust and Continental Crust

Answer 4

Oceanic Crust: 3.0 g/cm^3
Continental Crust : 2.7 g/cm^3

Question 5

Age of Oceanic Crust and Continental Crust.

Answer 5

Oceanic Crust :Less than 200 ma
Continental Crust :Up to 4 ba

Question 6

Mantle thickness

Answer 6

2900km

Question 7

The dominant rock type in the
uppermost mantle

Answer 7

peridotite ( richer in the metals magnesium and iron than the
minerals found in either the continental or oceanic crust)

Question 8

Thickness of upper mantle

Answer 8

660 kilometer

Question 9

which elements does core contain

Answer 9

nickel alloy with minor amounts of oxygen, silicon, and
sulfur

Question 9

Density of the core

Answer 9

11g/cm

Question 10

What is the outer core made of and give the thickness of it

Answer 10

is a liquid layer 2270 kilometers thic

Question 11

Give the radius of the inner core and the state of matter of it.

Answer 11

1216km(754mies) and is in solid form due to the pressure existing in the center of the planet

Question 12

ground shaking caused by the sudden and rapid movement of one block of
rock slipping past another along fractures in Earth’s crust, called faults

Answer 12

earthquake

Question 13

The location where slippage begins
is called

Answer 13

hypocenter or (focus)

Question 14

The point on Earth’s surface directly Figure above the hypocenter is called

Answer 14

Epicenter

Question 15

Faults Types

Answer 15

• Normal Fault
• Strike-slip Fault( or Transform fault)
• Reverse Fault

Question 16

How do they know large sections of Earth’s crust have been thrust upwards

Answer 16

Because fossils of
marine organisms have been discovered thousands of meters above sea level

Question 17

When H.F Reid conduct landmark study

Answer 17

1906

Question 18

rock behaves
elastically, much as a stretched rubber band does when it is released

Answer 18

“springing back” elastic rebound

Question 19

Strong earthquakes are followed by numerous earthquakes of lesser magnitude, called?

Answer 19

aftershocks

Question 20

formula to estimate the after shock knowing the main magnitude

Answer 20

after shock = main - 1.2

Question 21

precede major earthquakes by days or, in some cases, several years

Answer 21

foreshocks

Question 22

The study of earthquakes

Answer 22

Seismology

Question 23

intrument used to measure seismic waves

Answer 23

seismographs

Question 24

The records obtained from seismographs, called

Answer 24

seismograms

Question 25

Body Waves

Answer 25

primary waves(P waves) secondary waves(S waves)

Question 26

“push/pull” waves

Answer 26

P waves

Question 27

waves that change the volume of intervening material by alternately squeezing and stretching

Answer 27

P waves

Question 28

Waves that change the shape of the material that transmits them

Answer 28

S waves

Question 29

Speed of P waves and S waves

Answer 29

P waves travel 70percent faster than S waves

Question 30

speed of s waves and surface waves

Answer 30

S waves travel 10 percent faster than surface waves

Question 31

Scale created by Giuseppe Mercalli and when did he create it

Answer 31

In 1902 ( modified Mercalli Intensity Scale )

Question 32

of methods to determine two fundamentally different measures that describe the size of an earthquake

Answer 32

Intensity Scales and Magnitude Scale

Question 33

The most powerful earthquake ever recorded

Answer 33

The 1960 Valdivia, Chile earthquake and tsunami or the Great Chilean earthquake occurred on22 May 1960 (9.4 to 9.6 in magnitude )

Question 34

. Intermediate-sized plates

Answer 34

-Caribbean - -Nazca -Philippine -Arabian -Cocos -Scotia -Juan de Fuca

Question 35

The part where crust and upper mantle meet

Answer 35

Lithosphere (lithos = stone)

Question 36

large-scale movements of continent

Answer 36

continental drift

Question 37

How putted the jigsaw-puzzle

Answer 37

Eduard Suess

Question 38

who wrote a book about drift of continents and when ?

Answer 38

In 1915 by Alfred Wegener

Question 40

Who Showed Atlantic seafloor made of young basalt and NOT granite?

Answer 40

Maurice ‘Doc’ Ewing

Question 41

Who came up with Theory of sea floor spreading. Magma rises at mid-ocean ridges and as it cools plate move apart

Answer 41

Harry Hess

Question 42

iron rich mineral

Answer 42

magnetite

Question 43

. Basaltic lavas erupt at the surface at temperatures greater than......

Answer 43

1000 degrees

Question 44

exceeding a threshold temperature for magnetism known as

Answer 44

Curie point(585 degrees (1085F)

Question 45

Rocks that formed thousands or millions of years ago and contain a “record” of the direction of the magnetic poles at the time of their formation are said to posses........

Answer 45

paleomagnetism, or fossil magnetism

Question 46

When rocks exhibit the same magnetism as the present magnetic field, they are said to posses

Answer 46

normal polarity

Question 47

rocks exhibiting the opposite magnetism are said to have......

Answer 47

reverse polarity

Question 48

Who suggested that the stripes of high-intensity magnetism are regions where the paleomagnetism of the oceanic crust exhibits normal polarity. LIke they explained magnetic reversals of sea floor

Answer 48

Vine and Matthew

Question 49

The fault mechanism tells us whether.......?

Answer 49

the rupture was on a normal, a reverse, or a strike-slip fault.

Question 50

who showed that earthquakes at mid ocean ridges are due to normal faulting and proving the plate motions at MOR

Answer 50

Lynn Sikes

Question 51

when did Convergent Margins got identified

Answer 51

Between 1930's and 1940's

Question 52

who discovered Convergent Boundaries

Answer 52

Kiyoo Wadati , Hugo Benioff

Question 53

WHo showed that seismic waves traveling in these deep earthquake zones were strikingly anomalous from those traveling in other parts of the mantle

Answer 53

Jack Oliver and Bryan Isacks in 1967

Question 54

Provided evidence for strong sections of subducting mantle at convergent margin

Answer 54

Oliver and Isacks

Question 55

the overlying plate forms an extensive fault zone, called a

Answer 55

megathrust fault,

Question 56

Give earth earthquakes that are caused by Megathrust faults

Answer 56

-2011 Japan quake (M9.0) -2004 Indian Ocean (sumatra) quake(M9.1) -1964 Alaska quake (M9.2) -The largest earthquake is 1960 Chile quake (M9.5) -