The focus is the place inside Earth’s crust where an earthquake originates. The point on the Earth’s surface
directly above
the focus is the epicenter. When energy is released at the focus, seismic waves travel outward from that point in all directions.
What is the difference between focus and Hypocentre?
As nouns the difference between focus and hypocentre
is that focus is (countable|optics) a point at which reflected or refracted rays of light converge while hypocentre is (geology)
the focus of an earthquake
, directly under the epicentre.
What is the difference between the epicenter and the focus of an earthquake quizlet?
Focus is the first point of movement along a fault where all earthquake waves originate – it is below the surface. The epicenter is the point on the surface above the focus – the place on the surface that would receive the most intense vibrations.
What are the similarities of focus and epicenter?
1.An earthquake’s epicenter and focus are
both determinants of the origin of the ground movements
. 2. Epicenters are located on the surface of the Earth, while the focus is beneath the crust and located right below the epicenter. 3.In locating the origin of the earthquake, seismologists first locate the epicenter.
Where is the epicenter of the earthquake located?
The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and
the location directly above it on the surface of the earth
is called the epicenter. Sometimes an earthquake has foreshocks.
Which represents the epicenter of the earthquake?
The epicenter is
the point on the earth’s surface vertically above the hypocenter (or focus)
, point in the crust where a seismic rupture begins.
Where do earthquakes show the most damage?
The
epicenter
is the point on the land surface that is directly above the focus. In about 75% of earthquakes, the focus is in the top 10 to 15 kilometers (6 to 9 miles) of the crust. Shallow earthquakes cause the most damage because the focus is near where people live.
What is seismology used for?
1 Concept. Seismology is
the science of earthquakes to study the causes and effects of minute pulsation to most catastrophic natural phenomenon inside the earth
. The method can be classified broadly into two major divisions depending on the energy source of the seismic waves.
What is the meaning of Hypocentre?
The hypocenter is
the point within the earth where an earthquake rupture starts
. The epicenter is the point directly above it at the surface of the Earth. Also commonly termed the focus. See also epicenter.
How do you determine the epicenter?
Measure the difference in arrival times between the first shear (s) wave and the first compressional (p) wave, which can be interpreted from the seismogram.
Multiply the difference by 8.4
to estimate the distance, in kilometers, from the seismograph station to the epicenter.
What is the name of the instrument used for measuring earthquake?
Seismographs
are instruments used to record the motion of the ground during an earthquake.
What is the similarities of magnitude and intensity?
Magnitude is a measure of earthquake size and remains unchanged with distance from the earthquake. Intensity, however, describes
the degree of shaking caused by an earthquake at a given place and decreases with distance from the earthquake epicentre
.
What are the 10 causes of earthquake?
- Groundwater extraction – decrease in pore pressure.
- Groundwater – increase in pore pressure.
- Heavy rain.
- Pore fluid flow.
- High CO2 pressure.
- Building dams.
- Earthquakes.
- No earthquakes (Seismic quiescence)
Why is it important to know the epicenter of an earthquake?
The main importance in determining the epicentre is
so that the fault that ruptured causing the earthquake can be identified
. … If the fault is previously unknown (such as the 2010 Canterbury earthquake), then it is important because it means that the hazard models for the area need improvement.
How do you plot an earthquake epicenter?
Plot the epicenter at longitude-latitude coordinates using a small dot (·). Use a
dot of about 1mm in diameter for earthquake
magnitude 6.0-6.9; a larger dot (about 3mm in diameter for earthquakes of magnitude 7.0-7.9; and a large dot (about 1 cm in diameter) for earthquakes of magnitude 8.0 or greater.
What is intensity of earthquake?
The effect of an earthquake on the Earth’s surface is called the intensity. … The Modified Mercalli Intensity value assigned to a specific site after an earthquake has a more meaningful measure of severity to the nonscientist than the magnitude because intensity refers
to the effects actually experienced at that place
.
