Q. What is the term used to describe the fraction along earth crust?
Q. What do you call the point where an earthquake originates?
Ans: Focus or hypocenter
Q. Where is the intensity of tremor (vibrations) highest?
Ans: At the boundaries of the tectonic plates along fault.
Q. What do you call point on the earth surface that lies directly above the focus of an earthquake?
Q. Name the three layer of earth.
Ans: Crust, Mental and Core
Q. List two places in India which are most threatened by earthquake.
Ans: Two places in India which are most threatened by earthquake are
1. Kashmir 2. Rann of Kutch.
Q. What are the scientists who study about Earthquake called?
Q. Explain focus and Epicenter with respect to Earthquake?
Ans: The place below earth surface from where the earthquake originates is called the hypocenter or the focus of an earthquake. It is often several kilometers below the earth’s surface. The spot on the earth’s surface exactly above the hypocenter of an earthquake is the epicenter.
Q. Define these terms.
Ans: (a) Seismograph: A type of instrument used to measure earthquake.
(b) Seismic wave: The shock wave produced by earthquake.
(c) Seismology: The branch of science deeling with earthquake and related problem is called Seismology.
(d) Tectonic plate: The crust layer of earth is made up of a number of rocky slabs called tectonic plates.
Q. What do you do in following situation during earthquake
Ans: (a) You are sitting in film theatre ---> stay on seat and cover your head with arm
(b) You are at home watching TV-> Do not go to another room. Take shelter under a table and protect your head by wrapping your arms around it
(c) You are travelling in car: --> Drive slowly and do not come out till the tremors stop.
(d) You are in the basement of a building--> Take shelter under a table and protect your head by wrapping
your arms around it
Q. What is earthquake? How it is caused?
Ans: Ans: An earthquake is a sudden shaking or trembling of the earth lasting for a very short time.
Earthquake is caused due to the movement of tectonic plates that float over molten magma. As the
earth and felt as earthquake.
Q. Describe the scale commonly used to measure the magnitude of earthquake?
Ans: The magnitude of most earthquakes is measured on the Richter scale. The Richter magnitudes are based on a logarithmic scale (base 10). Each whole number you go up on the Richter scale, the amplitude of the ground motion recorded by a seismograph goes up ten times.
Q. What preventive steps should be taken to minimize the effects of earthquakes in future?
Ans: (a) We should build earthquake resistance building
(b) In earthquake prone area, light –weighted materials are used to build building
(c) Always take care to make sure ceiling fan, air conditioner etc fixed firmly.
Q. What are the after effects of earthquakes?
Ans: (a) Huge loss of life and property
(b) Fire may cause by inflammable material
(c) Sewer system may burst open
(d) Dams and embankments develop cracks
(d)In hilly are land slides