Dark Oxygen

Scientists have recently discovered a strange phenomenon, dubbed “dark oxygen” in the deep sea.

About Dark Oxygen:

•   Oxygen that is being produced in complete darkness thousands of feet below the ocean surface is termed dark oxygen.
•   Why is the discovery important?

o  Until now, it was thought that oxygen was created only through photosynthesis, a process that requires sunlight.

o  Oceanic plankton, drifting plants, algae, and some bacteria are the primary elements attributed to the production of oxygen in the ocean. All these organisms are capable of photosynthesis.

o  The production of oxygen at such depths is thought to be impossible because there isn't enough sunlight for plants to do photosynthesis.

o  However, in this case, oxygen is not being produced by plants.

o  The oxygen comes out of Polymetallic nodules that are similar in resemblance to lumps of coal.

o  These nodules, made up of metals like manganese, iron, cobalt, nickel, copper, and lithium, can generate oxygen through electrochemical activity even in the absence of light.

o  They are splitting H2O molecules into Hydrogen and Oxygen.

Key Facts about Polymetallic Nodules:

•   Polymetallic nodules, also known as manganese nodules, are small, rounded accretions found on the seabed of the deep ocean floor.
•  These nodules are composed of a mixture of metals and minerals, including manganese, iron, nickel, copper, cobalt, and traces of other valuable elements such as platinum, rare earth elements, and lithium.
•   They form through a slow and gradual process over millions of years.
•   They develop as concentric layers around a central nucleus, which can be a shell fragment, a shark tooth, or a piece of basaltic rock.
•   The layers are primarily composed of manganese and iron oxides, with other metals being deposited along with them.
•   These metals are really important for the production of lithium-ion batteries used in electric vehicle batteries, mobile phones, wind turbines, solar panels, etc.
•   They are mainly found in the north-central Pacific Ocean, the southeastern Pacific Ocean and the northern Indian Ocean.
•   It is said that there may be enough polymetallic nodules in an area of the Pacific Ocean called the Clarion-Clipperton Zone to meet global energy demands for decades after.

 UPSC Prelims PYQ : 2018

Ques : Consider the following statements:

1. The Earth's magnetic field has reversed every few hundred thousand years.

2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide.

3. When living organisms originated, they modified the early atmosphere of the Earth.

Which of the statements given above is/are correct?

a)  1 only

b) 2 and 3 only

c)  1 and 3 only

d) 1, 2 and 3

Ans : c)