Can you stealth against tremorsense?

I am confused to the interaction between the monster special ability tremorsense and skills of perception and stealth.

Specifically what my issue is that tremorsense gets to "automatically pinpoint the location of anything that is in contact with the ground".

When reading the perception rules you have "Creatures with the tremorsense special quality have a +8 bonus on Perception checks against creatures touching the ground and automatically make any such checks within their range".

The action for perception is "Most Perception checks are reactive, made in response to observable stimulus. Intentionally searching for stimulus is a move action." This could also be worded as "Most perception checks are automatic". Now this doesnt include pinpoint, which does matter?

So the automatically part is talking about the action to make the check, they dont have to focus or take time, it just happens. This is further supported by perception getting a bonus of +8 as long as both are touching the ground, otherwise, why bother giving a bonus to notice things if you are always successful in noticing things touching the ground within your range?

So, could you use stealth to sneak up on something ONLY using tremorsense?