This Is How the Japanese Measure Earthquake Events
The more you know, the better you're prepared.
Japan has been known for its devastating earthquakes. For those living in the country, it would be beneficial to learn more about them and how they are measured, especially since they happen frequently in Japan.
Everyone knows that earthquakes are measured by their “Magnitude.” This measures the amount of energy released at the earthquake’s epicenter and has a scale that can go up to as high as 9.5 magnitude. This mode of measurement is also used internationally.
In Japan, however, more than one scale is used for measuring an earthquake. One of them is the “Shindo.”
Shindo is a seismic intensity scale that measures the degree of shaking at a certain point on the Earth’s surface. The degree of shaking will vary depending on how far away from the epicenter the measurement is taken and the depth of the earthquake. The scale starts at 0 and can go up to as high as 7. The higher the number, the bigger the tremor.
If you’ve watched Japan’s earthquakes news, you’ll notice that there are nos. 0-7 indicated on the screen. Typically, an earthquake will only have one magnitude reading and several Shindo readings.
How will an earthquake feel like based on the Shindo measurement? Here’s a summary explaining the JMA Seismic Intensity Scale:
Shindo 0: Won’t feel anything.
Shindo 1: Felt slightly by some people who are staying still in buildings.
Shindo 2: Felt by many people who are staying still in buildings.
Hanging objects shake slightly.
Some people who are sleeping might get woken up.
Shindo 3: Felt by most people in buildings and some people walking.
Some of the sleeping people might get woken up.
Tablewares on the shelf may shake.
Shindo 4: Most people feel the shaking.
Hanging objects swing about and unstable ornaments may fall.
Shindo 5 Lower: Many people are frightened and feel the need to hold onto something stable.
Tablewares on the shelf or items on bookshelves may fall.
Unsecured furniture may move and unstable ornaments may topple over.
Glass windows may break and fall.
Shindo 5 Upper: Many people find it difficult to walk without holding onto something stable.
Tablewares on the shelf or items on bookshelves are more likely to fall.
Unreinforced concrete block walls may collapse.
Shindo 6 Lower: It is difficult to remain standing.
Many unsecured furniture moves and may become wedged shut.
Wall tiles and windows may sustain damage and fall out or break.
Shindo 6 Upper: It is impossible to move without crawling.
Most unsecured furniture moves and are more likely to topple over.
Wooden houses with low earthquake resistance are more likely to lean and
Shindo 7: Wooden houses or reinforced concrete buildings with low earthquake resistance
are more likely to collapse.
Wooden houses with high earthquake resistance may lean in some cases.
(20 June 2019)