Perhaps one of the most intriguing phenomenon worthy of the youngest of curiosities when at the beach is why is the ocean salty? This is an age-old question that is the subject of much research and yet, has been taken for granted. When at the beach, one can expect to taste the saltiness of the sea when swimming and find the opposite to be true of freshwater domains such as rivers, lakes, and streams.
According to the National Oceanic and Atmospheric Administration (NOAA), the ocean is salty due to runoff from rocks found on land. The runoff contains carbon dioxide that turns acidic when the carbon dioxide mixes with air which in turn erodes rocks. Ions are created and carried with the runoff that eventually ends up in the ocean where it takes on concentration over time causing the ocean to be salty (NOAA, 2008). This process has been ongoing for an estimated billions of years (NOAA, 2008). The more runoff that is produced, the more the sea has gotten saltier over time (Matthews, n.d.).
It is believed that atmospheric carbon dioxide changes that occurred during the ice ages and global warming are contributors to the increase in the production of runoff, causing an increase in the salt levels found in the ocean (Rae, et al, 2018). Studies have been conducted to measure the number of ions present in the ocean combined with carbon dioxide levels. There are increases in carbon storage and changes in the overall climate, circulation related to glacial timescales.
As our climate continues to change and global warming becomes more and more a factor in our world, it stands to reason these changes have major impacts to the ocean. The fact the ocean is salty may be taken for granted, but the ever-changing global dynamics that contribute to it should not be.
- Matthews, R. (n.d.). Are the oceans getting saltier? Retrieved from https://www.sciencefocus.com/planet-earth/are-the-oceans-getting-saltier/
- Rae, J. W. B., Burke, A., Robinson, L. F., Adkins, J. F., Chen, T., Cole, C., … Taylor, B. J. (2018, October 24). CO 2 storage and release in the deep Southern Ocean on millennial to centennial timescales. Retrieved from https://www.nature.com/articles/s41586-018-0614-0
- US Department of Commerce, & National Oceanic and Atmospheric Administration. (2008, November 14). Why is the ocean salty? Retrieved from https://oceanservice.noaa.gov/facts/whysalty.html