Good morning anons.
Planes don't just
>>5431373 lb Plane "appears" out of nowhere
Understand the way ADSB works. It's a network of volunteer transceivers on the ground who may or may not be in a position to pick up signals from aircraft. They feed their data to a server over the web, which puts the data into a database then displays position etc. on a map. It's an entirely crowd-sourced effort.
Have you noticed? There is no ADSB crowd-sourcing over wide stretches of ocean? Have you noticed? No ADSB crowd-sourcing over most parts of central Asia and Afric and interior South America?
Receiver density is high in North America and Europe.
Also, pilots have the ability to turn the ADSB transponder on/off. Military routinely disables their ADSB; mil radars can still pick them up without pinging the digital transponder.
With this in mind, the sudden "appearance" of a plane incoming from the Pacific is not at all unusual.