HOW IS THE INSTRUMENT FOR MEASURING THE INTENSITY OF EARTHQUAKES CALIBRATED?
`The Richter scale is used to measure the magnitude of an earthquake. Magnitude is a measure of an earthquake’s size, but rather than being a direct measure of the intensity of the ground shaking, it is a reflection of the strength of the seismic sound waves emitted by the earthquake, a phenomenon that can be detected at great distances from the earthquake’s epicentre. Because an earthquake’s magnitude can be determined solely by routine measurements made by seismometers, magnitude has become an important measurement commonly recorded on seismograms. The scale is logarithmic — this means that a factor-of-10 difference in actual earthquake energy corresponds to a difference of one whole number on the scale. WHAT ARE SUNSPOTS? The dark spots on the surface of the sun are called sunspots. These areas are locations for sudden changes in the magnetic environment or the ‘magnetic storms’. They appear darker in contrast to the surrounding areas, hence, the name. WHY IS A TRACTOR’S EXHAUST PIP
