SIESMIC AND ELECTRICAL METHODS

Question 1

-Are the most commonly conducted geophysical surveys for engineering investigations.
- _________ can be classified based on different criteria, such as wave type, survey technique, and application.

Answer 1

Seismic methods

Question 2

Any mechanical vibration is initiated by a source and travels to the location where the vibration is noted.

Answer 2

SEISMIC WAVES

Question 3

-The direction of travel is called the ____________________

Answer 3

ray, ray vector, or ray path.

Question 4

2 TYPES OF SEISMIC WAVES

Answer 4

1. BODY WAVES
2. SURFACE WAVES

Question 5

which pass through the volume of a material. These are the fastest traveling of all seismic waves

Answer 5

BODY WAVES

Question 6

travel through all media that support seismic waves; air waves or noise in gasses, including the atmosphere.

Answer 6

P-WAVES

Question 7

secondary or transverse or shear wave (S-wave). S-waves therefore do not exist in liquids and gasses

Answer 7

S - WAVES

Question 8

are produced by surface impacts, explosions, and waveform changes at boundaries. Surface waves travel slower than body waves.

Answer 8

SURFACE WAVES

Question 9

2 types of body waves

Answer 9

P-WAVES
S-WAVES

Question 10

2 TYPES OF SURFACE WAVES

Answer 10

LOVE WAVES
RAYLEIGH WAVES

Question 11

A type of seismic surface wave in which particles move with a side-to-side motion perpendicular to the main propagation of the earthquake.

Answer 11

LOVE WAVES

Question 12

an undulating wave that travels over the surface of a solid, especially of the ground in an earthquake, with a speed independent of wavelength, the motion of the particles being in ellipses.

Answer 12

RAYLEIGH WAVE

Question 13

Seismic methods can be classified based on how seismic waves are generated and measured

Answer 13

1. ACTIVE SEISMIC METHODS
2. PASSIVE SEISMIC METHODS

Question 14

3 TYPES UNDER ACTIVE SEISMIC METHODS

Answer 14

 Seismic Refraction
Seismic Reflection
Seismic Tomography

Question 15

__________- - is the study of seismic waves generated by natural earthquakes.

Answer 15

Earthquake seismology

Question 16

__________________ is a passive seismic technique that studies low-amplitude ground vibrations.

Answer 16

Microtremor analysis

Question 17

Seismic methods are used in various fields, leading to classification by purpose

Answer 17

Exploration seismology
 Earthquake seismology
 Engineering seismology
Environmental and groundwater studies

Question 18

The seismic method relies on four key components to effectively analyze subsurface structures

Answer 18

Seismic Source
Geophones or Hydrophones
 Seismograph
Data Processing

Question 19

seismic waves that propagate through the Earth. These sources can be natural, such as earthquakes, or artificial, like explosives, mechanical impacts, or specialized vibrators used in exploration

Answer 19

SEISMIC SOURCE

Question 20

Serve as sensors. ________ are used on land to record ground vibrations.

Answer 20

GEOPHONES

Question 21

are employed in water to capture pressure variations caused by seismic waves.

Answer 21

HYDROPHONES

Question 22

The equipment that records input geophone voltages in a timed sequence is the __________. Current practice uses ___________ that store the channels’ signals as digital data at discrete time.

Answer 22

seismograph

Question 23

It involves filtering noise, enhancing signals, and applying mathematical algorithms to generate detailed subsurface images

Answer 23

DATA PROCESSING

Question 24

detect the surface effects produced by electric current flow in the ground.

Answer 24

Electrical geophysical prospecting methods

Question 25

is a passive electrical geophysical method based upon the measurement of spontaneous or natural electrical potential developed in the earth d

Answer 25

The self-potential (SP) technique

Question 26

Also called Earth Current, natural electric current flowing on and beneath the surface of the Earth and generally following a direction parallel to the Earth’s surface.

Answer 26

TELLURIC CURRENT

Question 27

is a measure of the resistance of a given size of a specific material to electrical conduction.

Answer 27

Resistivity

Question 28

was one of the first electrical methods and was used as far back as 1912 by Schlumberger. As explained elsewhere in this volume, when electric energy is applied to two points at the ground surface, an electric current will flow between them because of their difference in electrical potential.

Answer 28

EQUIPOTENTIAL METHOD

Question 29

use transmitters to create strong time-varying primary magnetic fields that induce electrical currents to flow in conductive rocks. These currents, in turn, create secondary electromagnetic fields that are detected by receiver antennae.

Answer 29

Electromagnetic (EM) methods

Question 30

and resistivity are two electrical properties measured in near-surface sediments as indirect hydrocarbon indicators. They are usually measured at the same time by inserting two electrodes into the earth surface and passing a current through them

Answer 30

Induced polarization (IP)