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.
A Signal Ground is the common or return line for any signal. Typically it's the same as the Circuit Ground. A Circuit Ground is the signal common (return) connection for all the devices in a circuit. It's just a convenient reference point. Typically in a circuit you have one or more power points and a Circuit Ground (zero volts) point. It may or may not be connected to earth ground (typically not).