Topic 2 Part 2 Flashcards
is a non-instrumental perceptibility
measure of damage to structures, ground
surface effects, ( e.g. fractures, cracks and
landslides) and human reactions to earthquake
shaking.
Intensity
is a non-instrumental perceptibility
measure of damage to structures, ground
surface effects, ( e.g. fractures, cracks and
landslides) and human reactions to earthquake
shaking.
Intensity
It is a descriptive method which has been
traditionally used to establish earthquake size,
especially for pre-instrumental events.
Intensity
It is a descriptive method which has been
traditionally used to establish earthquake size,
especially for pre-instrumental events.
Intensity
It is a subjective damage evaluation metric
because of its qualitative nature, related to
population density, familiarity with earthquake
and type of constructions.
Intensity
is a measure of the total energy
released by an earthquake at its source
(hypocenter or focus).
•
Magnitude
is a measure of the total energy
released by an earthquake at its source
(hypocenter or focus).
•
Magnitude
• It is a quantitative, objective measure that does
not change with distance from the earthquake’s
epicenter.
Magnitude
• It is a single, objective value that is used to
compare the size of earthquakes globally
Magnitude
is calculated based on seismic data
recorded by seismographs, which capture the
amplitude of seismic waves.
Magnitude
is calculated based on seismic data
recorded by seismographs, which capture the
amplitude of seismic waves.
Magnitude
three different ways to measure the
size of an earthquake, each with its own
applications and methods for calculation.
Local Magnitude Scale, Surface Wave
Magnitude Scale, and Moment Magnitude
Scale
three different ways to measure the
size of an earthquake, each with its own
applications and methods for calculation.
Local Magnitude Scale, Surface Wave
Magnitude Scale, and Moment Magnitude
Scale
also known as the
Richter Scale, was the first widely used method
for measuring earthquakes.
• It was developed by Charles F. Richter in 1935 to
estimate earthquake size based on seismic
waves recorded at a certain distance from the
epicenter.
Local Magnitude Scale,
also known as the
Richter Scale, was the first widely used method
for measuring earthquakes.
• It was developed by Charles F. Richter in 1935 to
estimate earthquake size based on seismic
waves recorded at a certain distance from the
epicenter.
Local Magnitude Scale,
Primarily used to measure small to
medium-sized earthquakes in a local region,
generally within 600 km of the epicenter
Local Magnitude Scale,
The scale is most effective for
earthquakes of magnitude 3 to 7 and becomes less
accurate for larger earthquakes or those occurring
at great depths.
Local Magnitude Scale,
The scale is most effective for
earthquakes of magnitude 3 to 7 and becomes less
accurate for larger earthquakes or those occurring
at great depths.
Local Magnitude Scale,
measures
the size of earthquakes based on surface waves
(specifically Rayleigh waves) that travel along
the Earth’s surface.
• These waves tend to cause the most damage
during an earthquake because they have large
amplitudes and affect the Earth’s surface.
SURFACE WAVE MAGNITUDE SCALE,Ms
measures
the size of earthquakes based on surface waves
(specifically Rayleigh waves) that travel along
the Earth’s surface.
• These waves tend to cause the most damage
during an earthquake because they have large
amplitudes and affect the Earth’s surface.
SURFACE WAVE MAGNITUDE SCALE,Ms
It is most effective for large earthquakes
(magnitude 5.5 and above), but it is less accurate for
deep or distant earthquakes.
SURFACE WAVE MAGNITUDE SCALE,Ms
is the most
modern and widely used earthquake magnitude
scale.
• It measures the total energy released by an
earthquake, including energy from both body and
surface waves, and is especially effective for
large and deep earthquakes.
MOMENT MAGNITUDE SCALE,Mw
is the most
modern and widely used earthquake magnitude
scale.
• It measures the total energy released by an
earthquake, including energy from both body and
surface waves, and is especially effective for
large and deep earthquakes.
MOMENT MAGNITUDE SCALE,Mw
Designed to overcome the limitations of
the Richter and Surface Wave Magnitude scales,
Mw provides the most accurate measurement for
all earthquake sizes and depths
MOMENT MAGNITUDE SCALE,Mw
Works for all earthquake magnitudes, including
very large events (Mw 8 or higher) where the Richter
scale becomes less accurate.
• Can measure energy release more accurately for
deep-focus earthquakes and those that don’t
generate large surface waves.
MOMENT MAGNITUDE SCALE,Mw
calculated based on the
seismic moment (M₀), which is a function of the fault
area, the average slip on the fault, and the rigidity of the
rocks
MOMENT MAGNITUDE SCALE,Mw
calculated based on the
seismic moment (M₀), which is a function of the fault
area, the average slip on the fault, and the rigidity of the
rocks
MOMENT MAGNITUDE SCALE,Mw
is the standard
scale used by seismologists today, especially for
large or significant earthquakes, such as those
above magnitude 6.
• It is also the scale reported by the United States
Geological Survey (USGS) and other global seismic
monitoring agencies.
MOMENT MAGNITUDE SCALE,Mw
is the standard
scale used by seismologists today, especially for
large or significant earthquakes, such as those
above magnitude 6.
• It is also the scale reported by the United States
Geological Survey (USGS) and other global seismic
monitoring agencies.
MOMENT MAGNITUDE SCALE,Mw
