Why in the news?
- US scientists discovered the presence of offshore aquifers in the Atlantic Ocean from New Jersey to Maine.
Offshore Aquifers
- Definition: Offshore aquifers are bodies of porous rock or sediment containing freshwater located beneath the sea floor.
- Formation:
- Pleistocene Glaciation: During ice ages, sea levels were lower, and rainwater seeped into coastal sediments. As sea levels rose, the aquifers were submerged.
- Hydrological Processes: Freshwater flows from land through permeable sediments into offshore aquifers, trapped by confining layers.
- Global Distribution:
- Found along continental shelves worldwide (e.g., U.S. Atlantic coast, Australia, South Africa, and parts of India).
- Estimated to contain ~500,000 km³ of freshwater, mostly brackish but usable after treatment.
- Significance:
- Water Security
- Critical for coastal regions facing groundwater depletion (India, Middle East, Africa).
- Alternative source of freshwater for drought-prone and arid regions.
- Climate Change Resilience
- Provides backup during rising sea-level induced salinisation of coastal aquifers.
- Scientific Importance
- Offers insights into paleo-climate and hydrological cycles.
- Water Security
- Challenges:
- Extraction Difficulty: Located hundreds of meters below seabed, requiring advanced drilling & desalination.
- Environmental Risks: Over-extraction could cause saline intrusion and ecological imbalance.
- Legal Issues: Not clearly governed under UNCLOS (Law of the Sea) – disputes possible.
- Economic Cost: High cost of exploration, drilling, and treatment compared to traditional water sources.