Why in NEWS
A recent study reveals that nearly 99.999% of Earth’s deep seafloor—which spans two-thirds of the planet—remains visually unexplored, with most exploration efforts concentrated in limited zones and by only five countries.
Key Concepts & Definitions
| Term | Definition |
|---|---|
| Deep Ocean | Oceanic region below 200 meters depth, beyond sunlight penetration, marked by cold temperatures and high pressure. |
| Abyssal Plains | Vast, flat regions of the deep ocean floor, covering a majority of the seabed but largely unexplored. |
| Marine Snow | Organic debris falling from upper ocean layers, serving as a food source for deep-sea organisms and contributing to carbon sequestration. |
What the Study Revealed
| Aspect | Detail |
|---|---|
| Extent of Exploration | 99.999% of the deep seafloor remains visually unobserved. |
| Depth Threshold | Deep sea refers to depths beyond 200 meters. |
| Dominant Countries | Over 97% of deep-sea dives were conducted by the US, Japan, New Zealand, France, and Germany. |
| Exploration Bias | Focus has been on ridges, seamounts, and canyons; abyssal plains remain neglected despite covering vast areas. |
Deep Ocean Ecology
| Factor | Description |
|---|---|
| Temperature | Averages 4°C in deep ocean regions. |
| Pressure | Ranges from 40 to over 110 times atmospheric pressure. |
| Light & Nutrients | Sunlight does not penetrate; area is nutrient-poor, yet hosts diverse life. |
| Mesopelagic Zone | Depths between 200–1000 m, holds around 90% of global fish biomass, including fish, krill, and squid. |
India’s Deep Ocean Mission (DOM)
| Feature | Details |
|---|---|
| Launch Year | 2021 |
| Objective | To explore, conserve, and harness deep-sea resources in a sustainable manner. |
| Focus Areas | Polymetallic nodules, hydrothermal sulfides, biodiversity, and climate studies. |
Significance of Deep Ocean Exploration
| Domain | Relevance |
|---|---|
| Energy Security | Oil, gas, ocean currents, and methane hydrates lie beneath. |
| Climate Insight | Deep ocean processes influence global carbon cycling and climate regulation. |
| Medicine | Deep-sea microbes could lead to the discovery of new antibiotics. |
| Mineral Wealth | Polymetallic nodules contain nickel, cobalt, and rare earth elements. |
In a Nutshell (Mnemonic)
“D.E.E.P. S.E.A.”
- D – Depths beyond 200 m
- E – Exploration dominated by 5 countries
- E – Energy resources below
- P – Plains (Abyssal) largely ignored
- S – Sequestration via marine snow
- E – Extreme conditions, cold & pressure
- A – Antibiotics & minerals potential
Prelims Practice Questions
- Which of the following best defines the deep ocean?
A) Ocean below 20 meters
B) Ocean beyond continental shelf
C) Ocean below 200 meters depth
D) Ocean with high salinity - Marine Snow plays a crucial role in:
A) Warming deep ocean water
B) Supporting coral reef ecosystems
C) Carbon transport and deep-sea food chain
D) Generating ocean currents - Which country is not among the top five in conducting deep-sea dives?
A) Japan
B) India
C) Germany
D) New Zealand
Prelims Answers and Explanations
| Qn | Answer | Explanation |
|---|---|---|
| 1 | C | Deep ocean is defined as areas below 200 m where sunlight cannot penetrate. |
| 2 | C | Marine snow sustains deep-sea life and transports carbon to ocean depths. |
| 3 | B | India has launched DOM but is not among the top five countries in actual dives. |
