If the coast-to-coast distance is about 2900 miles, it will take about ...
... (2900 mi)/(186000 mi/s) ≈ 15.6 ms
for the signal to travel coast-to-coast at light speed.
_____
There are time delays due to the amplifiers and repeaters required in the path, and due to the fact that the signals don't actually travel at the speed of light in a wire.
A test of internet speed between Seattle and Washington, DC shows a round-trip time of about 87 ms when traffic is light. Modern communication channels tend to be faster than the telegraph (especially when measured in words per minute).
Control over the press and media and control of who leaves and comes to North Korea.
The basaltic rock that forms volcanic mountains where the mantle plumes reach the Earth's surface is usually composed of fine-grained, dark-colored felsic materials. Basalt is a hard, black rock which is formed when magma or lava from volcanic eruptions cools down and hardens. It consists of fine mineral grains. It can also consist of holes that were filled by volcanic gases. Basalt is black because the minerals that it is made up of contains iron. Iron gives basalt its black colour.
