What is required of someone who entered into a state of Ihram for Umrah from Jeddah, then returned there and took off his Ihram due to an emergency circumstance?

If you stipulated at the time of assuming ihram that you would exit ihram wherever you were detained, and then an impediment arose that prevented you from completing the rites, then there is nothing upon you. However, if you did not stipulate this, or if there was no valid excuse permitting you to exit ihram, then you remain in your state of ihram. You must wear the ihram garments and go to Makkah to complete your Umrah without the need for a new ihram. As for any ihram prohibitions you committed, especially those involving destruction (such as cutting hair and trimming nails), it is more cautious that you offer a fidyah, which gives you the choice between fasting for three days, feeding six poor persons, or sacrificing a sheep.