Yes, my bunker can survive a tidal wave. Just as my house survived the tsunami in Indonesia by being in LA at the time.
I for one cannot believe people keep asking this same question on this forum. It's so incredibly off-topic and irrelevant.
If a "tsunami" covers your shelter, your worries will be at an end. If you built your shelter below 300 feet above sea level, you picked a bad spot for your shelter.
Otherwise, tsunamis will be the least of your worries if we have a magnetic reversal. You're going to be more concerned with watching your skin boil off at 20,000 rads an hour, especially when you realize that guy was right on Survive2012 about it taking only 3 meters of overhead cover to reduce that to nearly zero. So you guys above ground with your knapsack waiting to surf the tsunami may realize in your final days that was a pretty bad strategy. Even if you had plenty of "consensus" on the Survive2012 forum.
Listen to Tex. The average human being experiences a really powerful sickening sensation when you start to understand that what you really need in this world, is a deep underground shelter. Everything else is mostly off-topic.
P.S. If you can't build a shelter, then you can get better or superior shielding belowground in a parking garage. I was looking at an internal room two stories underground in the building where I work, the walls were a foot thick and the air was filtered in two spirals coming down to you before it then passed through a giant air vent with an upward turn. No fallout can traverse two 300 meter circles in the air, it will settle. If I was away from home somewhere, this is the kind of place I'd take shelter in immediately during a radiological threat. Most people could not afford a million dollar shelter of this standard. Above your head on the surface, people outdoors during a failure of the magnetic shield would be cooking inside their own skins like sausages, while you would be belowground receiving nearly zero rads of anything.