Maria Semple’s 2012 novel, “Where’d You Go, Bernadette,” is steeped in locations, from its primary setting of Seattle to the (literal) far ends of the earth that its eponymous malcontent is compelled to visit. But even as a “drooling fan” of the author, Oscar-winning actor Cate Blanchett had never visited Seattle and never met Semple — even if she’d read the book long before starring in the movie version. “We spoke on the phone and had a long email exchange, then I spent a weekend with her where she took me around to all the haunts she wrote about in the novel,” Blanchett, 50, said via phone from Toronto, where she was promoting the movie. Still, Blanchett had to employ a host of dramatic tricks to get inside the head of Bernadette Fox, the genius architect and doting mother whose life explodes at the exact moment her family (and neighbors) need her most. We talked to the Australian actress before the Aug.