ENVIRONMENT FOR UPSC PRELIMS 2020 , SOLUTION OF TEST-26

1 . Solution (d)

2 . Solution (b)

3 . Solution (d)

Thwaites Glacier  sometimes referred to as the Doomsday Glacier , is an unusually broad and vast Antarctic glacier flowing into the Pine Island Bay, part of the Amundsen Sea, east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land (Antarctica).

Thwaites Glacier is closely watched for its potential to raise sea levels. Along with the Pine Island Glacier, it has been described as part of the “weak underbelly” of the West Antarctic Ice Sheet, due to its apparent vulnerability to significant retreat. In recent years, the flow of both of these glaciers has accelerated, their surfaces have lowered, and their grounding lines have retreated.

4 . Solution (b)

5 . Solution (d)

6 . Solution (b)

Polymetallic nodules (also known as manganese nodules) are potato-shaped, largely porous nodules found in abundance carpeting the sea floor of world oceans in deep sea.

7 . Solution (d)

8 . Solution (c)

9 . Solution (d)

Eon – half a billion years or more
Era – several hundred million years
Period – tens to ~one hundred million years
Epoch – tens of millions of years

10 . Solution (a)

As of July 2020, neither the International Commission on Stratigraphy (ICS) nor the International Union of Geological Sciences (IUGS) has officially approved the term as a recognised subdivision of geologic time.