Answer:
a parachute ceremony
Step-by-step explanation:
Appositives are nouns, pronouns or phrases that rename, identify or give further information of another noun placed right beside it. There are two types of appositives: restrictive, which are not essential to the sentence, and therefore should be set off with commas, dashes or brackets, and nonrestrictive, which are essential to the meaning of the sentence and does not require to be separated by any type of punctuation.
In the sentence, the phrase "a parachute ceremony" is the appositive phrase because it renames and identifies the phrase noun "One of the strangest weddings of all time." Furthermore, it is also nonrestrictive because it is not necessary to the meaning of the sentence.