EARTH SCIENCE
EARTHQUAKES
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
a place where no seismic waves can be detected from a specific earthquake
|
|
|
a place on earth where shadow appear larger
|
|
|
the place where shadow of an earthquake appear
|
|
|
None of the above
|
Detailed explanation-1: -The seismic shadow zone is the rea of the Earth’s surface where seismographs cannot detect an earthquake after the waves have passed through the earth. P waves are refracted by the liquid outer core and are not detected between 104° and 140°
Detailed explanation-2: -A seismic shadow zone is an area of the Earth’s surface where seismographs cannot detect direct P waves and/or S waves from an earthquake. This is due to liquid layers or structures within the Earth’s surface.
Detailed explanation-3: -1. Seismic shadow zone is the zone on Earth’s surface where seismographs don’t detect earthquakes because seismic waves don’t reach there. 2. The P-wave shadow zone does not receive any direct P waves as it gets refracted.
Detailed explanation-4: -A seismic shadow zone is not in a constant place; each earthquake epicenter has a different shadow zone. The finding of shadow zones allowed scientists to prove Earth had an interior layer of liquid.
Detailed explanation-5: -A zone between 105° and 145° from the epicentre was recognized as the shadow zone for both the wave types. The entire zone beyond 105° does not receive S-waves.