I'm not exactly certain why the huge % of Asian population in California. I have no real good answer to that question.
The seismic activity is related to Death Valley but only barely. Badwater in Death Valley is 250 feet below sea level because it part of a subduction zone where one tectonic plate goes under another. Otherwise, it is located in a dry desert and considered the hottest place on earth. The former President Ronald Reagan once had a television show "Death Valley Days".
There is stunning wealth in California, and poverty. The farm workers are paid horribly substandard wages and whole areas are economically depressed.