With the recent events in Crimea and the Ukraine the name of the peninsula appears a lot in both written and spoken, the a at the end is very conspicuous in the English pronunciation and writing, since there is no a in the Russian or Ukrainian name of the peninsula. The name is Крым in Russian, and Крим in Ukrainian. It's clearly seen that the name ends with an M and is pronounced Krim.
According to an article in the Washington Post the name of the peninsula in the language of the local Crimean Tatar population is Qırım.
What is the source for the distortion of the name in English?
(Also, it seems that the same a appears in the French, Spanish and Italian name, and doesn't appear on the German name).