Erta Ale is a remote and rarely visited volcano that is known currently to have an active lava lake in its summit crater. Erta Ale has undergone seven eruption events in the past 125 years.
Re: What are the differences between Signal ground, Chasis ground and Earth?? Signal Ground is a reference point from which that signal is measured, due to the inevitable voltage drops when current flows within a circuit, some 'ground' points will be slightly different to others. There may be several signal grounds in a circuit.
It is a protective ground which is connected to the earth ground. Earth ground is a metal rod really dug deep in ground outside the building to sink current and provide ground zero. Signal ground need not be connected to this, Signal ground is a common return path for the signal.