32. And another medium quake in Calif today

Headline: "Quake Rattles California Coast Near San Diego"

see news story here

As the news story says, this quake was estimated as a 4.0 scale. Sounds puny, but it was 10 times larger than any other this last month in California. No injuries or damage.

Do you know how the Richter Scale works?
True or False: A 6.0 scale earthquake is twice as big as a 5.0 scale quake.
FALSE.
A 6.0 scale quake is ten times larger than a 5.0 scale quake.

And a 7.0 quake is a hundred times as big as a 5.0 quake.
And the 8.0 quake is a thousand times as big as a 5.0 quake.
Each number in the Richter scale goes up ten-fold.

Here are a few Richter Scale ratings for noteworthy quakes:
Damage usually occurs at 6.0 and above.

2004 Indian Ocean quake that raised the tsunami: 9.0-9.3 (one hundred times larger than 1994 and 1989 quakes listed below)
1994 Northridge, CA quake : 6.8
1989 San Francisco/Oakland, CA: 6.9-7.1 happened during practice for the 1989 World Series between (strangely) San Francisco vs. Oakland
1985 Mexico City, Mexico quake : 8.1 (Approx 10-15 times as large as either of the two CA quakes)
1964 Alaskan earthquake: 8.5-9.2 (measurements differ, but largest ever in No.Amer.)
1906 San Francisco, CA quake: est 7.8-8.1 (based on damage, no measuring equipment)
1755 Lisbon, Portugal quake & tsunami: est 9.0, opinions differ. Almost leveled the city.

A survival service of The Future History.
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