Should Sankalpam change depending on where it is taken? Which words of the Sankalpam should change if it performed in the US/UK? I refer to terms like Jambo dweepe, Bharatha varshe, etc.
Yes, jambu dweepe, bharata varshe, dandakaranye, godavaryah dakshine teere, etc. denote the location.
Here are two pages with substitutes for USA.
For the USA:
- Krouncha Dweepe: In the island called Krouncha
- Ramanaka Varshe: In the region called Ramanaka Varsha
- Aindra Khande: In the continent called Aindra
- Prasantha Saagare: Near the Pacific Ocean
- Pushkara Kshetre: In the locale known as Pushkara
- Rocky - mickelny Parvatayor Madhye: Between Rockey and Mickelny mountains
- Misissipi- Missouri Ityadhi Aneka Shodasa Jeeva Nadeenam sameepa stite: The place that is surrounded by such perenniel rivers like Mississipi, Missouri and 16 other rivers
Here is a page with substitute for UK region.
Shalmali dhweepe vinyaschitha paschima dhik bage samudra madyasthitha brihadharanya kshethre London maanagare (replace with any city in the UK you live in)"
Krouncha Dweepe: In the island called Krouncha Ramanaka Varshe: In the region called Ramanaka Varsha
I am not an expert but I think the above two doesn’t represent the continent and country instead they represent a region in universe and earth respectively. And only Bharat Khande represent India. In that case changing the first two doesn't make sense.
According to our Shastras, any act done after crossing the seas would yield no fruit. That is why, "strictly" orthodox people would hesitate to take foreign tours/stay there and make it their homes.Further Bharata Kanda is considered as "Karma Bhoomi",where any one is rewarded for any religious act done as followed by his elders. If however one is particular in observing rituals, he could recite the same Mantras as we believe that the Gods/rivers etc which are invoked immediately make Their presence .(Gange cha yamunechaive -----Jaleasmin sannidhim kuru)Only the rivers flowing in / mountains etc in India are considered auspicious and are capable of answering to the prayers of the devout.