Mega tsunamis can only be caused by massive impacts. Whether it be from solar impact or local physical impact.

Landslides can generate all sorts of probabilities.

A massive impact from a solar source could be the reason the earth became extinct to a degree. This seems to be the popular conclusion.

A lead wave of inconceivable size could have wiped out all land mass life as we knew it. Only for mother nature to wipe the slate clean and start again.

My wave is bigger than yours ?

If it satisfies you then I concede..............

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Thank God for magnetism.