All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible for you, Allaah willing, to encourage the Muslims to contribute to help the victims of the earthquake even if they are non-Muslims as there is no Islamic impediment that prevents from being kind to the non-Muslims. Allaah Says (what means): {Allaah does not forbid you to deal justly and kindly with those who fought not against you on account of religion and did not drive you out of your homes. Verily, Allaah loves those who deal with equity.}[Quran 60:8]
Providing them with help and assistance while they are in urgent need is an encouragement for them to become Muslims.
It is permissible also for whoever has performed his obligatory Hajj and intends to perform an optional one to cancel the Hajj and give his money in charity (to help the victims). However, some jurists stated that optional Hajj is better than charity with the exception when there is a need for sustenance. Imaam Maalik was asked: "Which one is better for you, Hajj or charity?" He replied: "Hajj is better unless there is famine."
Finally, it should be noted that people must be reminded to be patient through this calamity and learn a lesson from it and take the initiative to repent to Allaah.
Allaah Knows best.