UPSC STATIC QUIZ – Geography : 17 February 2024

Solution: b)

Statement 3 is incorrect.

A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth’s rotation period. 

Different orbits:

• A Geosynchonous Orbit (GEO) takes a satellite around the Earth at a rate of once per day, keeping it roughly in the same area over the ground.
• A Geostationary Orbit (GSO) is a geosynchronous orbit with an inclination of zero, meaning, it lies on the equator.

All geostationary satellites are geosynchronous. Not all geosynchronous satellites are geostationary.

Solution: c)

Arctic warming and jet stream migration

The Arctic is warming three to four times faster than the globe as a whole, meaning there is ever less difference between northern temperatures and those closer to the equator.

That is resulting in swings in the North Atlantic jet stream, which in turn leads to extreme weather events like heatwaves and floods.

Heat domes

Warmer oceans contribute to heat domes, which trap heat over large geographical areas.

Scientists have found the main cause of heat domes is a strong change in ocean temperatures from west to east in the tropical Pacific Ocean during the preceding winter.

As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, resulting in heatwaves.

El Niño and La Niña

Every few years, the climate patterns known as El Niño and, less frequently, La Niña occur. El Niño brings warm water from the equatorial Pacific Ocean up to the western coast of North America, and La Niña brings colder water.

Solution: b)

Statement 2 is incorrect.

Constant eruptions at the crest of oceanic ridges cause the rupture of the oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side. The ocean floor, thus spreads, known as sea floor spreading.

Sea floor spreading is verified using these phenomena:

• It was realised that all along the mid-oceanic ridges, volcanic eruptions are common and they bring huge amounts of lava to the surface in this area. The sediments on the ocean floor are unexpectedly very thin.
• The age of the rocks increases as one moves away from the crest.
• The ocean crust rocks are much younger than the continental rocks.
• The sediments on the ocean floor are unexpectedly very thin.
• The deep trenches have deep-seated earthquake occurrences while in the mid-oceanic ridge areas, the quake foci have shallow depths. It means lava is in close vicinity.

Solution: a)

Only Statement 1 is correct.

When moisture laden winds cause rainfall in western slopes, upon moving to eastern sides they lose much of their moisture. Rainfall is less, and thus vegetation is less thick at eastern slopes.

Nilgiri Biosphere Reserve extends to Eastern Slopes.

Solution: b)

Statement 3 is incorrect.

A total lunar eclipse occurs when the Earth casts its shadow completely over a full moon, blocking reflection of all direct sunlight from the lunar orb and dimming the color of the moon to a reddish hue, hence the term “blood moon.”

This is only possible when the orbits of the Earth, moon and sun align so that the moon is directly behind Earth relative to the sun. Otherwise, the moon passes above or below Earth’s shadow because its orbit around Earth is usually tilted relative to Earth’s orbit about the sun.

The reddish appearance of the lunar surface — the moon does not entirely disappear from view — is caused by rays of sunlight around the outer edge of the eclipse shadow, or umbra, being filtered and refracted as it passes through Earth’s atmosphere, bathing the moon indirectly in a dim copper glow.

The degree of redness depends on atmospheric conditions that vary with levels of air pollution, dust storms, wildfire smoke and even volcanic ash.

Total lunar eclipses occur, on average, about once every year and a half, according to NASA. But the interval varies.