Magnetism of the Sun/ PaleoMagnetism Flashcards

1
Q

Intense magnetic field of the sun is associated with

A

Sunspots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Sunspots also emit hydrogen gas called

A

Solar Flares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is a plasma which is an ionized gas.

A

SOlar wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

interaction of the solar wind with the Earth’s magnetic field forms the

A

Magnetosphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The
outer boundary of the magnetosphere is the

A

Bow shock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

a region of turbulent motion

A

Magnetosheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The geomagnetic field
stretches out on the night side of the Earth forming the

A

Magnetotail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

boundary between the
Earth’s magnetic field and the solar wind is the

A

Magnetopause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The charged particles that penetrate the magnetopause and are trapped by the Earth’s
magnetic field form the

A

Van Allen Radiation Belts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Energetic particles cause ionization of molecules of nitrogen and oxygen in the atmosphere
forming an ionized region called the

A

Ionosphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The ionosphere is located at an altitude of
about

A

50 km and 1500 km.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T or F: direction of remanent
magnetization was that of the geomagnetic field during cooling.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The apparatus consists of two identical small magnets mounted horizontally at opposite ends of a short
rigid vertical bar so that the magnets are oriented exactly antiparallel to each other.

A

astatic magnetometer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

is the study of the geomagnetic field recorded in dateable historic artefacts.

A

Archaeomagnetism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

This imaginary magnet has its north pole near the geographic South Pole and its south pole near the geographic North Pole, roughly aligned with the Earth’s rotation axis.

A

Axial Geocentric Dipole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Axial Geocentric Dipole

A

Axial Geocentric Dipole

17
Q

if data are averaged over a long enough interval
of time, the mean paleomagnetic pole position will coincide with the axis of rotation of the Earth.

A

axial geocentric dipole hypothesis

18
Q

it is
possible to calculate where the geomagnetic pole would need to be to produce the observed declination
and inclination.

A

Virtual Geomagnetic Pole

19
Q

If samples are measured from a large number of recent lava flows covering a long enough period of time,
the mean direction of the collection will correspond to the field of an

A

axial geocentric dipole

20
Q

Pole representing an averaged value of the field, is called

A

Paleomagnetic Pole

21
Q

_________of a rock
was acquired at the time of formation of the rock (or at a known time in its history), and has since remained
unaltered.

A

natural remanent magnetization (NRM)

22
Q

Laboratory techniques must be applied that eliminate the undesirable components and isolate the
primary magnetization. This process is called __________

A

Magnetic Cleaning

23
Q

This type of magnetic cleaning can be produced in a coil by passing an alternating current through it.

A

alternating magnetic field

24
Q

when a rock sample is heated to a given temperature T, magnetic components that have lower
blocking temperatures than T are _________

A

Thermally Randomized

25
Q

T or F: paleomagnetic sampling includes a field test that can establish the stability of the demagnetization over geological time.

A

False

26
Q

It is applied to samples taken from
beds that were originally horizontal and have been tilted by later tectonic effects.

A

Fold Test

27
Q

If the magnetization was acquired by the rock after it was folded, it will have a uniform direction at all
points of the fold

A

Post Folding Magnetization

28
Q

If the paleomagnetic direction in the rock is stable, it will experience the same rigid-body rotation as the
tilted strata; its direction will vary around the fold

A

prefolding magnetization

29
Q

If magnetization is acquired during the tectonic event; this case the direction of magnetization changes
around the fold but by a smaller amount than the folding

A

(synfolding magnetization)

30
Q

T or F: Suppose we are investigating a limestone formation and that we discover a conglomerate containing
cobbles of the limestone. their paleomagnetic directions, if stable, should be evenly distributed.

A

False

31
Q

During intrusion of a dike or sill the adjacent layers of the host rock are baked by contact with the hot
lava and acquire a TRM when they cool.

A

Baked Contact Test

32
Q

If samples taken from the lava and contact zone of the host rock have the __________ magnetization direction .

A

Same

33
Q

This test can be applied when the paleomagnetic samples represent a large enough time
interval (>10 ka) to have recorded normal and reversed polarities of the magnetic field

A

Reversals Test

34
Q

T or F: presence of an unremoved secondary component will give resultant normal and reversed directions
that are no longer antiparallel.

A

True