Module 1: Introduction Flashcards
Density of Core
1600 kg/m^3
Also known as the Mantle
Asthenosphere
Also known as the Crust
Lithosphere
Also known as the Core
Barysphere
The earth is conceived to be composed of a sequence of shells or layers called
Geosphere
Density of Steel
7850 kg/m^3
Density of Mantle
6000 kg/m^3
Core’s weight is _____ of steel’s weight.
Twice
What causes the earth’s mass to circulate?
Convection Current
TRUE OR FALSE
The earth’s crust is static but not subjected to motion.
False - not static but subjected to motion
These are gigantic rock plates that float in slow motion in a viscous (partially plastic) mantle.
Tectonic Plates
Thickness of tectonic plates
About 80km
These plates are pushed against and subduct under the continental plates, resulting in continental drift.
Oceanic Plates
It is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur.
Pacific Ring of Fire
Are vibrations or oscillations of the ground surface caused by a transient disturbance of the elastic or gravitational equilibrium of the rocks at or beneath the surface of the earth.
Earthquakes
The gradual accumulation and subsequent release of stress and strain is described as _______________.
Elastic Rebound
TRUE OR FALSE
The upper parts of the earth’s crust and lithosphere are very strong and brittle.
True
Earthquakes that occur along the boundaries of the tectonic plates.
Interplate Earthquakes
Earthquakes that occurs within the plates themselves, away from the plate boundaries.
Intraplate Earthquakes
Slips generated during earthquake at the fault along both horizontal and vertical directions.
Dip Slip
Slips generated during earthquake at the fault along the lateral direction.
Strike Slip
It has been used as a measure of earthquake size
Seismic Moment
This theory implies that an earthquake relieves the accumulated stresses along the portion of the fault on which rupture occurs.
Elastic Bound Theory
Large rigid blocks that makes up the earth’s crust.
Crustal Plates
Three kinds of plate boundaries or marginal zones
Divergent
Convergent
Transform
Kind of plate boundary that is described as the constructive margin. It occurs when two tectonic plates move away from each other.
Divergent Boundary
Kind of plate boundary that is described as the destructive margin. It occurs when two plates from opposite directions come together and collide.
Convergent Boundary
Kind of plate boundary that is described as the conservative margin. These are places where plates slide sideways past each other.
Transform Boundary
According to PHIVOLCS, this is a break, fracture, fissure or zone of weakness where movement or displacement had occurred or may occur again.
Fault
It is a fault that has moved within the last 10,000 years.
Active Fault
Also known as the Valley Fault System (VFS) and is a dominantly right-lateral strike slip fault system in Luzon.
Marikina Valley Fault System
The Philippine Fault transverse from ________ in the north to the eastern __________ in the south.
Ilocos Region to Mindanao
Length of the Philippine Fault
1300 km
Density of Crust
1500 kg/m^3
Application capable to do proximity searches to active faults.
PHIVOLCS FaultFinder
The vibrations felt in the bedrock are called.
Shocks
The largest strain energy released during an earthquake travels in the form of ____________ in all directions.
Seismic Waves
These waves travel through the interior of the earth consisting of P-waves and S-waves.
Body Waves
These waves are results from interaction between body waves and surface layers of earth
Surface Waves
Two types of Body Waves
P(primary) - waves and S(secondary) - waves
Two types of Surface Waves
Love waves and Rayleigh Waves
It is an instrument used to measure the vibration of the earth and relatively weak ground motions.
Seismograph
The record produced by seismograph is called —–
Seismogram
The location of an earthquake implies the location of its ——–
Epicenter
Is a non-instrumental perceptibility or qualitative measure of damage to structures, ground surface effects, and human reactions to earthquake shaking.
Intensity
is a seismic scale used and developed by the PHIVOLCS to measure the intensity of an earthquake.
PHIVOLCS Earthquake Intensity Scale (PEIS)
It is the measure of the amount of energy released at the focus.
Magnitude
It is the size of seismic waves
amplitude
A map that shows the intensity where the epicenter is near.
Isoseismal Map
This is the most flexible and best to use magnitude scale
Moment Magnitude (Mw)
4 most common magnitude scales
Richter or Local Magnitude (ML)
Body Wave Magnitude (Mb)
Surface Wave Magnitude (Ms)
Moment Magnitude (Mw)
5 Seismic Hazards
Ground Rupture
Ground Shaking
Liquefaction
Earthquake-Induced Landslide
Tsunamis
Phenomenon wherein sediments, especially near bodies of water, behave like liquid similar to quick sand
Liquefaction
Down slope movement of rocks, soil and other debris commonly triggered by strong shaking.
Earthquake-Induced Landslide
Series of waves caused commonly by an earthquake under the sea
Tsunamis
Deformation on the ground that marks the intersection of the fault with the earth’s surface.
Ground Rupture
Disruptive up, down, and sideways vibration of the ground during an earthquake.
Ground Shaking
It is the displacement of the ground due to movement of the fault.
Fissuring
Also known as the Gutenberg Discontinuity
Core-Mantle Boundary
Forms when the body waves reflect and refract off of the surface of the Earth.
Surface Waves
When an oceanic plate collides with a continental plate, it slides beneath the continental plate forming a ———–
Deep Oceanic Trench
Geologic Fault in which the hanging wall has moved downward relative to the footwall.
Normal Fault
Geologic Fault in which the hanging wall has moved upward relative to the footwall.
Thrust or Reverse Fault
The depth of the focus of the epicenter is known as ——————
Focal Depth
The point of generation of an earthquake is known as the ——– or ———
Focus or Center
The point on the earth’s surface directly above the focus is known as ———–
Epicenter
The distance from the epicenter to any point of interest is known as the ——– or ———-
Focal Distance or Epicentral Distance
