Name: How Does The Richter Scale Work?
Uploaded: 2021-04-26T14:19:03.000Z
Duration: 4 min 57 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Earthquakes strike all over the world, and once they're over a certain threshold, they

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But what do those numbers they tell you on the news really mean?

Nepal was recently hit by a 7.3 on the Richter Scale, less than 3 weeks after being hit by

The 7.8 destroyed buildings, killed thousands and caused an avalanche; the 7.3 caused a

Does Zero Point Five on the scale make that big a difference?

Firstly, let me step back for a bit, when you describe a great dessert to a friend,

We humans love to rate things -- but to truly rate it fairly, you'd have to understand the

ingredients, the preparation, the plating, and the ideal dessert comparison, what you've

just eaten prior, what you're drinking, where you're sitting, the temperature in the room

you're in and your mood at the time; not to mention whether you had a fight with your

Science needs history, context, and tons of points of data, and that's just for a piece

How can you take all that data and turn it into one simple rating?

They measure how they FEEL about it, right?

Like a layer cake, earthquakes are all different.

When rocks slide, knock and buffet against one another; they can slip, crack or jerk

and cause an earthquake, but the friction, the fault, the pressure, depth, type of rock

and varied stressors of its history; all matter.

To turn that into one number is pretty crazy, if you think about it.

The Richter scale was invented in the 1930s to give some understanding to the magnitude

of a quake as measured by seismographs; ground monitoring equipment.

It's logarithmic, so every 1.0 point on the scale is a TEN FOLD increase.

So a 3 to a 4 is a ten-fold increase, and 3 to a 5 is 100 fold; or, put another way,

a 7 is a 10,000 times more powerful than a 3.

The U.S. Geological Survey says there are 1.4 million quakes that register above 2.0

every year, and only 16 that get a 7 or higher, but even after I've explained it to you, do

Richter is only concerned with the amount of energy released by a single quake, and

Maybe it was deep, or away from a populated area, maybe the quake was under soft ground,

or in the middle of firm bedrock -- all of that would change how it was experienced;

Mercalli Scale or Modified Mercalli Scale, measures intensity.

This is used by the U.S. Geological survey to understand how the earthquake FELT on the

The Mercalli scale was developed in the 30s too and it uses Roman numerals to determine

It is subjective, so, for example, a II is weak and is quote "Felt only by a few persons

at rest,especially on upper floors of buildings," but a VI is strong and quote "Felt by all,

Some heavy furniture is moved; a few instances of fallen plaster.

This measure of how it FEELS adds more data to what happened in an earthquake, moving

us closer to understanding what really happened!

There's also the Moment Magnitude scale, which is a new measure for quakes.

Moment Magnitude allows scientists to use computer models to create synthetic seismograms

and determine exactly how the energy released relates to the magnitude of a quake.

Essentially how far a fault moved, and the force required to move it.

It gets seismologists really excited because it's WAY more accurate than the antiquated

Richter measurements, works all over the world as a standard measure, and can go above M8,

According to the Incorporated Research Institutions for Seismology, the April 25th earthquake

in Nepal was a M7.8 with MMI ranging from IV to IX.

Most of the reports were in V to VI -- so it felt strong, the ground moved and for some

This complicated cocktail of factors that have to be considered help determine how earthquakes

are experienced, and categorized; just like anything we can always learn more.

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How Does The Richter Scale Work?

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