1. An earthquake can erupt. Emotions can erupt. Anger can erupt.
Example: An earthquake erupted in Sicily last night.
Surge means a sudden powerful forward or upward movement. A wave surges. A crowd surges. A storm surges.
Example: Birds search for fish when waves surge towards the shore.
2. ‘Trace’ means to find out, to copy, to draw an outline, etc. ‘Finding out’ is the closest meaning to ‘trace’ in the text.
3. I can’t find the word ‘undistinguished’ in my dictionary because it is not the root word. It is there under the word ‘distinguished’ because ‘undistinguished’ is opposite to ‘distinguished’. It means: not specific, not prominent, not distinct, etc.