Tag: causes of earthquakes

Fault zones are highly prone to earthquakes.

Answer is A.

The amplitude of vibrations measured on the Richter's scale increase by steps of about 10.
The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are included in the magnitude formula to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquakes. On the Richter Scale, magnitude is expressed in whole numbers and decimal fractions. For example, a magnitude of 5.3 might be computed for a moderate earthquake, and a strong earthquake might be rated as magnitude 6.3. Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value.

Answer is B.

The point within the earth along the rupturing geological fault where an earthquake originates is called the focus, or hypocenter. The point on the earth's surface directly above the focus is called the epicenter. Earthquake waves begin to radiate out from the focus and subsequently form along the fault rupture. 
Hence, the statement is false.

Answer is A.

Earthquakes are caused by by shaking of the earth, strain building up in the tectonic plates, plates slipping along the fault lines, etc. and the Tsunamis can also be caused by volcanic eruptions, underwater detonations and even landslides.
Because we cant get deep enough into the Earth to see what happens before an earthquake or tsunami happens, therefore we cant predict when its coming.

Answer is B.

Seismograph is an instrument that makes a record of seismic waves caused by an earthquake, explosion, or other Earth-shaking phenomenon. Seismographs are equipped with electromagnetic sensors that translate ground motions into electrical changes, which are processed and recorded by the instruments analog or digital circuits. A record produced by a seismograph on a display screen or paper printout is called a seismogram.
Hence, it is not a scale and the statement is false.

Answer is B.

The fracture along blocks of crust (tectonic plates) is called a fault or fault line.
A fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes.

Seismograph is a device which is used to record and measure seismic waves created by earthquakes.

The S waves moving through the planet make the medium to move perpendicular to the direction of the propagation of the wave. Therefore. the S waves are regarded as the transverse waves.