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.
terrain-awareness warning system A system using an electronic map that provides a warning of higher terrain in the vicinity of the aircraft. The TAWS is a computer-based system providing the flight crew with visual and acoustic alerts about the unintended approach to the terrain, taking into account the flight stage, flight crew response time, and aircraft speed.