Geophysics Flashcards
He discovered Uranus.
William Herschel
He proposed the geocentric model.
Aristotle
He proposed the heliocentric model.
Aristarchus
Volume of Earth
1.0832 × 10^21 m3
Mass of Earth
5.9736×10^24 kg
Mean Density of Earth
5.515×10^3 kg
Area of Earth
5.10×10^14 m2
An empirical formula to express the approximate distances of the planets from the Sun
Bode’s Law
Rate of increase of Earth-Moon distance.
3.7 cm/yr
Distance between Earth and Moon
384,400 km
Enumerate the Milankovitch cycles and the periods
Eccentricity: 100,000 years
Precession: 26,000 years
Obliquity: 41,000 years
The flattening ratio of the Earth
1/298
A method in geophysics used to image sections of the Earth’s subsurface using different geophysical surveys
Tomography
Directly measures small differences in the strength of gravity. What is its accuracy?
Gravimeter. Accuracy: 0.1 mgal
Gravity correction done by repeatedly recording readings from a fixed “Base Station” throughout the day.
Drift Correction
Gravity correction that accounts for the gravitational attraction of the mass above sea level datum. Assumes the topography is flat.
Bouguer Correction
Periodic gravity variation correction caused by the combined effects of Sun and Moon.
Tidal Correction
Utilizes one current electrode and one potential electrode at a specific distance a.
C1-a-P1
Pole-pole
Utilizes two current electrodes separated by a distance, a, from two potential electrodes separated by distance, a. The distance between two Cs and Ps are given by na.
C2-a-C1-na-P2-a-P1
Dipole-dipole
Utilizes two paired current and potential electrodes separated by distance a, with each pair also separated by distance a. Potential electrodes are closer to each other while current electrodes are farther from each other.
C1-a-P1-a-P2-a-C2
Wenner
Utilizes two paired current and potential electrodes separated by distance na, with each pair separated by distance a. Potential electrodes are closer to each other while current electrodes are farther from each other.
C1-na-P1-a-P2-na-C2; a<na
Schlumberger
Describe the Eotvos effect when an object is moving against and along Earth’s rotation.
1.) Moving against Earth’s rotation = lesser upward centrifugal force = object weigh less
2.) Vice versa
_________ and __________ fused together to form the supercontinent Laurussia
Baltica and Laurentia
He visualized the heavens as a celestial sphere that surrounded the flat Earth.
a. Anaximander
b. Claudius Ptolemy
c. Nicolas Copernicus
d. Eratosthenes
Anaximander
He estimated the Earth’s circumference
a. Anaximander
b. Claudius Ptolemy
c. Nicolas Copernicus
d. Eratosthenes
Eratosthenes
He proposed the geocentric model
a. Anaximander
b. Claudius Ptolemy
c. Nicolas Copernicus
d. Eratosthenes
Claudius Ptolemy
Is the largest dwarf planet in the Solar System, what is the 2nd largest dwarf planet?
Pluto (1st)
Eris (2nd)
is the largest object in the asteroid belt between Mars and Jupiter, and it’s the only dwarf planet located in the inner solar system.
Ceres
is the largest of the five known natural satellites of Pluto
Charon
Calculated the accurate values of the parameters of Earth’s orbit.
a. Carl Friedrich Gauss
b. Lord Charles Cavendish
c. Keith Edward Bullen
d. Tycho Brahe
Tycho Brahe
Created a model of the internal structure consisting of 7 concentric shells.
a. Carl Friedrich Gauss
b. Lord Charles Cavendish
c. Keith Edward Bullen
d. Tycho Brahe
Keith Edward Bullen
Coined the value of Gravitational Constant G to be 6.754×10^-11.
a. Carl Friedrich Gauss
b. Lord Charles Cavendish
c. Keith Edward Bullen
d. Tycho Brahe
Lord Charles Cavendish
Developed a method of absolute determination of the intensity of the Earth’s magnetic field.
a. Carl Friedrich Gauss
b. Lord Charles Cavendish
c. Keith Edward Bullen
d. Tycho Brahe
Carl Friedrich Gauss
a low-eccentricity Kuiper belt object (KBO) that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune.
Classical Kuiper Belt Object or Cubewanos
Largest Satellite in the solar system.
Ganymede
The ratio of the intensity of the remanent magnetization to that of the induced magnetization.
Konigsberger Ratio
The two natural satellites of Mars
a. Io
b. Phobos
c. Ganymede
d. Charon
e. Deimos
Deimos and Phobos
Planets that rotate clockwise direction
Venus and Uranus
Crest vs. Hinge
Crest - highest point
Hinge - Maximum stress point
Crest vs. Hinge
Crest - highest point
Hinge - Maximum stress point
Describe Harmonic and Disharmonic Folding.
The thinner the rock the more harmonic. Same types also result to more harmonic. More Harmonic, the shorter the wavelength
Why do faults have a tendency to branch out on the near surface?
Because there is lesser confining pressure near the surface
What is the width of the Philippine Fault Zone?
5 km
In a rock core, if you see a repetition of bed, it is an indication of what fault? If there is an omission of strata what fault is it?
Repetition - Thrust Fault
Omission - Normal (but can also be Unconformity)
The presence of listric fault connotes a presence of _________ bed
thick incompetent bed
Series of listric and/or thrust faults
Imbrication system
Also called an imbricate structure
Schuppen structure
Allochthons are not common in the Philippines because?
Because our rocks are denser compared to continental rocks which are harder to thrust
Subduction should reach ______ km to create volcanoes.
90-100 km
a weather device that is designed to be dropped out of an aircraft at specified altitudes and due to the force of gravity, drop to the Earth
Dropsonde
A law that states that good absorbers of a given wavelength are also good emitters of that wavelength.
Kirchoff’s rule
It is composed of 8% Alkali and 45% SiO2
a. Trachyandesite
b. Trachybasalt
c. Basaltic Trachyandesite
d. Tephrite
Tephrite
A log that measures the resistivity using two electrodes and having a limited area of investigation of from 5 to 10 times the electrode diameter
Single-Point Resistivity Log
What signal is the most important for seismic refraction profiles?
First arrival time of the seismic waves. This signal is critical because it provides the earliest indication of seismic energy traveling through subsurface layers, allowing for the determination of layer velocities and depths.
Other signals are not that important because:
Subsequent arrivals: These may include reflected or refracted waves from deeper layers, but they do not provide as direct information about the near-surface conditions.
Amplitude variations: While they can indicate material properties, they are secondary to the timing of first arrivals in establishing depth and velocity profiles.
