I don't know where they even got that pronunciation from. The wikipedia page says "Karakoram (English: /ˌkɑːrəˈkɔːrəm, ˌkær-/, Urdu: [kaːɾaːkoːɾəm])"
none of which is [kerəkɑːrəm] as the author suggests
https://en.wikipedia.org/wiki/Karakoram
https://en.wiktionary.org/wiki/Karakoram