We had some early-morning excitement today: the second “big” earthquake since we came to Okinawa. Here, earthquakes are much smaller and more infrequent than on mainland Japan. Just like Canada knows its winter windchill, Japan knows its earthquakes. Japan has its own earthquake scale. Whereas the Richter scale measures the amount of energy released by an earthquake, the Japanese scale measures the degree of ground shake (“shindo”), so you can actually compare the shaking you felt with the intensity at the epicenter. Below are some numbers for comparison.
March 2011 earthquake: 8.4 shindo
This morning’s epicenter: 6.6 shindo
What we felt: 3 shindo
We’re fine, please don’t worry!
