Under Shia jurisprudence a woman can not terminate a marriage but she can ask her husband to terminate the marriage and he must do it. If he refuses, she is stuck. He will have to answer for his oppression on the day of judgement, but that doesn't make her any less stuck.
However, in mutah, the woman is not obligated to obtain her husband's consent for her travels. She can not end the marriage but she can simply leave. If she does leave, she can not marry again until the marriage term and iddah have passed.