The Quaternary undersea valley Fosse Dangaered, and Castle Hill landslip at the English portal, caused concerns. Identified by the 1964â65 geophysical survey, the Fosse Dangaered is an infilled valley system extending 80 metres (262 ft) below the seabed, 500 metres (1,640 ft) south of the tunnel route in mid-channel.
Best Answer: Magnetic forces can be caused by an electric current. Or they can be caused by magnetic domains aligned correctly. These domains are magnetic moments created by moving atoms in the material who have an electric dipole (usually).
The forces that govern wind velocity include the pressure gradient force, the Coriolis âforceâ (an apparent force due to Earthâs rotation) and friction. The pressure gradient force is what causes the wind to blow. In the atmosphere, pressure differences are a result of changes in density due to warm and cold air. When warm and cold air is close together, we have a pressure gradient.