Tag: earthquake

Wind erosion has the greatest impact on areas with dry soil because it is easier for wind to pick up and transport dry, light soil. Characteristically, deserts have dry soil, or sand, that is easy to transport. Also, deserts often have fewer physical barriers, such as hills, trees, or other structures, that can slow the wind movement.

Earthquake refers to a sudden violent shaking and vibration of the earth's surface resulting from underground movement along a fault plane or from volcanic activity. Earthquakes can cause serious destruction to property, injury to people and even death. It happens when there is sudden movement or breaking of the tectonic plates.

The moving ice mass downslope under the impact of gravity is called a glacier. About 10 percent of the earth's surface is now covered by the glacier. Glacier is formed due to the accumulation of ice above snow-line under extreme cold climate.

Cirque is a bowl-shaped, amphitheater-like depression eroded into the head or the side of a glacier valley. Typically, a cirque has a lip at its lower end. A cirque may also be a similarly shaped landform arising from fluvial erosion.

Ice is the poorest sorter of sediment. Glaciers can transport almost any size sediment easily, and when ice flow slows down or stops, the sediment is not deposited, due to the density of the ice. As a result, sediments deposited directly by ice when it melts are usually very poorly sorted. Significant sorting only occurs in glacial sediments that are subsequently transported by melt water from the glacier. Wind, on the other hand, is the best sorter of sediment, because it can usually only transport sediment that ranges in size from sand to clay. Occasional variation in wind speed during transport serves to further sort out these sediment sizes.

When glaciers melt or recede they deposit the rock materials brought by them in heaps of various shapes and size. These are known as moraines. Moraines are depositional feature and consist of rock materials of heterogeneous shape and size.

Answer is A.

The intensity of earthquake is measure on the richter scale.
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.