Correct Option
The correct option is (a).
Explanation
Salinity refers to the total content of dissolved salts in seawater, typically expressed in parts per thousand (ppt). While the average salinity of the oceans is approximately 35 ppt, certain landlocked water bodies exhibit hypersaline conditions due to high evaporation and limited freshwater influx.
Statement-wise Analysis
- Statement 1 is Correct: The Dead Sea is a salt lake bordered by Jordan to the east and Israel and the West Bank to the west. It lies in the Jordan Rift Valley and is the lowest point on Earth's land surface.
- Statement 2 is Incorrect: The average salinity of the open ocean is approximately 35 grams per litre (35 ppt). In contrast, the Dead Sea is one of the world's saltiest bodies of water, with a salinity of approximately 340 grams per litre (34%), which is nearly ten times that of the ocean.
- Statement 3 is Incorrect: The high concentration of dissolved salts significantly increases the density of the water in the Dead Sea. According to the principles of buoyancy, objects (including swimmers) float more easily in denser fluids. Therefore, swimmers float effortlessly in the Dead Sea rather than sink.
Key Takeaway
The Dead Sea is a hypersaline lake located between Israel and Jordan. Its extreme salinity (approx. 340 ppt) results in high water density, providing exceptional buoyancy that prevents swimmers from sinking.