Question

The average ocean salinity is 35ppt, meaning for every 1 liter of seawater, there are 35 grams of salt. If a creek is fed from an ocean, and rainwater runoff is the only contribution of freshwater, what do you predict your salinity test’s ppt will be? Why?

A) Less than 35ppt, because rainwater dilutes the salt content.
B) 35ppt, because the ocean water is the primary source.
C) More than 35ppt, because rainwater cannot dilute the ocean's salt content.
D) Cannot be determined from the information given.

Answer 1

a. The salinity of the creek will be less than 35ppt, because rainwater dilutes the salt content.

Step-by-step explanation:

The salinity of a creek that is fed from an ocean and receives only rainwater runoff as a freshwater source will likely have a salinity test ppt that is A) Less than 35ppt, because rainwater dilutes the salt content.

When rainwater falls onto land, it dissolves minerals in rock and soil, which increases its salinity but at lower levels compared to seawater. Therefore, the added freshwater from rainwater will dilute the salt content, resulting in a lower salinity than the average ocean salinity of 35ppt.