I ran the numbers into an impact calculator with the following settings, presuming a general worst case scenario for size and density, so 300 meters wide and solid iron, the most common angle of 45 degrees, and a slightly above average speed at 20km/s.
Total energy release was 7.65x10^18 Joules, or about 2 000 MT of TNT equivalent. That sounds like a lot, and it is a lot. Of that energy about 90% is impact energy.
But the Sendai earthquake released 3.8X10^22 Joules, more than 9 000 000 MT of TNT equivalent.
Frankly, unless that asteroid hits an ocean close by an island, any tidal wave it generates is likely to be irrelevant compared to everything else it does.
Also Doggerland flooded as sea levels rose and the latest ice age mostly quit. And Chixculub is a poor example for the damage a sea based strike does; at the time of the dinosaurs Chixculub was a rather shallow sea, while the tidal wave did tremendous damage, it did not do as much damage as the massive fan of debris and ejecta that traveled the world and lit a good chunk of it on fire. That's what killed the dinosaurs, the massive global cool down that resulted from all the dust and soot in the air following the impact.
Total energy release was 7.65x10^18 Joules, or about 2 000 MT of TNT equivalent. That sounds like a lot, and it is a lot. Of that energy about 90% is impact energy.
But the Sendai earthquake released 3.8X10^22 Joules, more than 9 000 000 MT of TNT equivalent.
Frankly, unless that asteroid hits an ocean close by an island, any tidal wave it generates is likely to be irrelevant compared to everything else it does.
Also Doggerland flooded as sea levels rose and the latest ice age mostly quit. And Chixculub is a poor example for the damage a sea based strike does; at the time of the dinosaurs Chixculub was a rather shallow sea, while the tidal wave did tremendous damage, it did not do as much damage as the massive fan of debris and ejecta that traveled the world and lit a good chunk of it on fire. That's what killed the dinosaurs, the massive global cool down that resulted from all the dust and soot in the air following the impact.