When planning a cross-continental flight, 9 times out of 10 a pilot will choose to fly around the Pacific Ocean. The reason has to do with finding the fastest route by flying in a straight line.
You might think that pilots’ top priority is safety, but really they fly as close to a straight line as they can. This means traveling across the 3D surface of our planet where it is narrowest. Thus many routes that travel from North America to Asia fly over Alaska and down the coast of Asia to their destination.
Sometimes the pilot will choose to fly directly over the ocean in order to make use of jet streams or to avoid a storm. The turbulence over water is also much lower because turbulence happens when hot air rising from the ground collides with the cold air up in the atmosphere. Man, there really are a ton of factors for pilots to take into account. We really should give more credit to the brave women and men who fly the friendly skies.