Was the Earthquake Alone Responsible for the Fukushima Meltdowns?

http://www.japansubculture.com/2011/07/einstein-insanity-nuclear-meltdowns-and-tokyo-electric-power-company-an-oped/

http://www.theatlanticwire.com/global/2011/07/meltdown-what-really-happened-fukushima/39541/

I've read several analyses that answer "yes" to this question. The link above also answers affirmatively. If earthquakes alone can cause these reactors to meltdown, than the nuclear plants in California--especially San Onofre and Diablo Canyon--are "ticking time bombs," to use Dr. Kaku's language.