Some of my ancestors were Latvian Jews who came to the U.S. in 1904. I'm trying to figure out whether any part of this branch of my family might still exist in the eastern hemisphere. After the Hitler-Stalin pact, Latvia became part of the USSR. The Soviets probably deported about 5000 Latvian Jews to the gulags, and about half of those are believed to have survived. The Germans invaded in July 1941, and of the approximately 75,000 Jews who were in Latvia then, probably only about 1000 survived. Of these, apparently most remained in Germany, Austria, or Italy, rather than returning to Latvia.
Based on these facts, it seems likely that most eastern-hemisphere descendants of Latvian Jews today would be the descendants of those who were deported to the gulags. Where would these people probably be now? People who were sent to the gulags apparently did not have full rights to live where they wished, even after their terms were up, and some were deported multiple times. Is it likely that their descendants would now be living in places like Novosibirsk and Krasnoyarsk, or more likely that they would have moved to places like Russia or Israel?
There do, for example, appear to be communities of Jews in Novosibirsk and Krasnoyarsk.
Here are the sources of information I've found so far:
Wikipedia: History of the Jews in Latvia
latvianhistory.com: Soviet mass deportations of 14 June 1941