Yes, seawater is salty. The salinity of seawater, or the concentration of salt, is approximately 35 parts per thousand (ppt), meaning about 3.5% of seawater's weight comes from dissolved salts.
The Salinity of Seawater
The ocean's saltiness is primarily due to the constant influx of minerals from land. Rainwater erodes rocks and soil, dissolving minerals and carrying them into rivers, which eventually flow into the oceans. These minerals, including sodium and chloride (which together constitute over 90% of dissolved ions), accumulate in the ocean. While some salts are removed through processes like sedimentation, the continuous input from rivers and other sources significantly outweighs the loss.
- Key Ions: Chloride and sodium are the most abundant ions in seawater.
- Salinity Percentage: Approximately 3.5% of seawater's weight is salt.
- Global Salinity: Oceans cover about 70% of the Earth's surface, and the vast majority of this water is saline.
Why the Ocean Remains Salty
The process of evaporation plays a crucial role in maintaining the ocean's salinity. When seawater evaporates, the water molecules turn into vapor and enter the atmosphere, leaving the dissolved salts behind. This process concentrates the salt in the remaining water, contributing to the ocean's overall salinity.
The U.S. Geological Survey (https://www.usgs.gov/faqs/why-ocean-salty) and NOAA (https://oceanservice.noaa.gov/facts/whysalty.html) both confirm the high salinity of ocean water and explain the process of how minerals from land contribute to the ocean's saltiness through runoff and evaporation.
