EARTHQUAKE Flashcards
is a natural phenomenon that is characterized by sudden, violent shifting of massive plates underneath the Earth’s surface.
EARTHQUAKE
What is hypocenter (focus)?
A point within the Earth were the earthquake originates
The point on the Earth’s surface directly above the focus is called?
The epicenter.
What is produced when the hypocenter is located near the surface, from 0-70km?
Deep shallow-focus earthquakes
What is produced If it is intermediate or located approximately 70-700 km?
Deep-focus earthquakes
What is a Fault?
These are crack across which rocks have been offset first.
They are fracture on the Earth’s crust where rocks on
either side have slid or pass each other
What are the part of a Fault?
Fault Plane, Fault trace, Hanging wall, Footwall
Classification of Faults
Normal Fault, Reverse Fault and Strike-Slip Fault
WHAT ARE SEISMIC WAVES?
Seismic waves are caused by the sudden movement of materials within the Earth, such as slipping along a fault during an earthquake.
What does seismologist studies?
they try to determine factors that contribute to or foretell an earthquake.
SEISMIC WAVES in a short description. (own way)
Seismic waves are categorized into two: Body waves and Surface waves. Body waves have two types P waves and S waves. Surface Waves have two types: Love waves and Rayleigh waves.
It is a seismic wave that moves through the interior of the earth. There are two types: Compressional or Primary Waves (P waves) and Shear or Secondary Waves (S waves)
BODY WAVES
It travels fastest at a speed from 4 to 8 km per second (km/s) at the Earth’s crust, hence they are the first to arrive at a location.
P waves
It usually travels at approximately 2.5-4 km per second (km/s) and can only travel through solid materials, unlike the P waves which can move through all states of matter.
S waves
It is a seismic wave that is trapped near the surface of the earth. typically generated when the source of the earthquake is close to the
Earth’s surface.
SURFACE WAVES
move transverse to the direction of the propagation but with no vertical motion. They cause rocks to move horizontally or side to side at a right angle to the direction of the traveling wave.
LOVE WAVES
Also called ground roll, cause rock particles to move upward, up, backward and down in a path that contains the direction of the wave travel.
RAYLEIGH WAVES
measures size of the earthquake, called ________. is determined using the
seismic waves created by the earthquake.
Magnitude
Locating an earthquake seismologists use a _______ for this data. With this, triangulation becomes possible to locate the earthquake. The epicenter is the point where the 3 circles intersect.
Travel time chart
Guiseppe Mercali (1902)
he developed the scale using the observations of the people who experienced the earthquakes to estimate. Its intensity, which is why
on its own, it was not considered scientific
Charles F. Richter (1934)
He was able to scientifically calculate the the magnitude of earthquake. He used the distance between the earthquake and the seismograph and amplitude of the largest recorded seismic wave.
They both introduced the Moment Magnitude Scale
(MMS). Here, the total energy content of the seismic waves is determined by computer analysis and corrected for the distance between the earthquake and the seismograph.
Thomas C. Hanks & Hiroo Kanamori (1979)
