The winds that blow from the Subtropical High Pressure Systems (STHP) called the trade winds because it helped in trade when trade and commerce was mostly conducted with the help of sailing vessels. Those vessels required wind for travelling. These winds were thus called trade winds. I hope the answer helps.
The seismic focus is the point in the earth's crust where an earthquake originates from.
Folk culture is more likely to have an anonymous origin and to diffuse slowly through migration, whereas popular culture is more likely to be invented and diffuse rapidly with the use of modern communication.