Daily Quiz: UPSC Prelims Marathon – August 10, 2018

Both the statements are correct.

The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity.

Relative Humidity = [Actual amount of water vapor in air (absolute humidity)/humidity at saturation point (the maximum water vapor air can hold at a given temperature)] X 100

• Temperature influences the actual amount of water vapour present in the air thus decides the moisture carrying capacity of the air.
• It decides the rate of evaporation and condensation, and therefore governs the degree of stability of the atmosphere.
• As relative humidity is directly related to the temperature of the air, it affects the nature and types of cloud formation and precipitation.

Statement a is incorrect.

Despite its name, the North Equatorial Current is not connected to the equator. It is a significant Pacific and the Atlantic Ocean current that flows from east to west. They flow in between 100 north and 20 north latitudes. In both oceans, it is separated from the equatorial circulation by the equatorial countercurrent, which flows eastward.

Statement b is correct.

South Equatorial Current is a significant ocean current in the Pacific, Atlantic and the Indian Ocean that flows from east to west. They flow in between the equator and about 200 south. In the Pacific and Atlantic Oceans, it extends across the equator to about 50 north.

Statement c is correct.

Mixing of cold and warm ocean currents bear richest fishing grounds in the world.

Example: Grand Banks around Newfoundland, Canada and North-Eastern Coast of Japan.

The mixing of warm and cold currents help to replenish the oxygen and favor the growth of planktons, the primary food for fish population. The best fishing grounds of the world exist mainly in these mixing zones.

Statement d is correct.

The west-wind drift is a cold ocean current and moves from west to east direction, right around the Antarctica.

Statement 1 is correct.

As air moves from high to low pressure in the northern hemisphere, it is deflected to the right by  the Coriolis force. In the southern hemisphere, air moving from high to low pressure is deflected to the left by the Coriolis force.

Statement 2 is incorrect.

In an El Niño year, air pressure drops over large areas of the central Pacific and along the coast of South America.

The normal low pressure system is replaced by a weak high in the western Pacific.

The wind patterns are aligned in such a way that the vertical wind shear is increased over the Caribbean and Atlantic. The increased wind shear helps to prevent tropical disturbances from developing into hurricanes. In the eastern Pacific, the wind patterns are altered in such a way to reduce the wind shear in the atmosphere, contributing to more storms.

The primary reasons of Monsoon type of climate is the difference in the rate of heating and cooling of land and sea.

In the summer, when the sun is overhead at the Tropic of Cancer, a low pressure is created in Central Asia. The seas, which warm up much slower, remain comparatively at high pressure.

At the same time, the southern hemisphere experiences winter, and a region of high pressure is set up in the continental interior of Australia. Thus, the winds blow outwards as the South-East Monsoon, to Java, and after crossing the equator are drawn towards the continental low pressure area reaching the Indian sub-continent as the South-West Monsoon. In the winter, conditions are reversed.

The earthquakes near the Himalayan region are generally triggered due to the collision between Indian and Eurasian tectonic plates.

The Himalayan Mountains were formed by the collision between Indian and Eurasian  tectonic plates and series of thrust faults control the seismicity of the Himalaya and contribute to the geomorphological evolution.

Continuous strain accumulations along the major active faults due to locking resulted in the high susceptibility of earthquake hazard in the region. The major earthquakes in the Himalayan region like Kangra Earthquake (1905), Nepal-Bihar Earthquake (1934) and Assam earthquake (1950) have occurred south of the Himalaya.

Statement 1 is correct.

Tropical cyclones move from east to west and turn north at 200 latitude and west at 300 latitude then move away from equator.

The movement of Cyclones in Arabian Sea and Bay of Bengal is a little different.

Here, these storms are superimposed upon the monsoon circulation of the summer months, and they move in northerly direction along with the monsoon currents.

Statement 2 is incorrect.

Continuous supply of moisture from the sea is the major driving force behind every cyclone. On reaching the land the moisture supply is cut off and the storm dissipates.

All of the above natural hazards (Tsunami, intense ground shaking and landslides) can be triggered by an earthquake.

Tsunami

Tsunami is also called seismic sea wave, or tidal wave, catastrophic ocean wave, usually caused by a submarine earthquake occurring less than 50 km (30 miles) beneath the seafloor, with a magnitude greater than 6.5 on the Richter scale. Underwater or coastal landslides or volcanic eruptions also may cause a tsunami.

Ground shaking:

Shaking of the ground caused by the passage of seismic waves, especially surface waves near the epicentre of the earthquake are responsible for the most damage during an earthquake.

Landslides and ground subsidence:

Avalanches, landslides, slumps and rock slides are triggered by ground shaking. These landslides are often more destructive than the earthquakes. A residential area in Alaska (Turnagain Heights) was destroyed by a shock induced landslide as well as are in downtown Anchorage.