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## What type of tools and measurements do scientists use to describe earthquakes?

Earthquakes are measured using seismographs, which monitor the seismic waves that travel through the Earth after an earthquake strikes. Scientists used the Richter Scale for many years but now largely follow the “moment magnitude scale,” which the U.S. Geological Survey says is a more accurate measure of size.

## What two types of measurements do scientists use to describe the size of earthquakes?

There are two ways in which scientists quantify the size of earthquakes: magnitude and intensity. You have probably heard of the Richter scale which is still used for small earthquakes, but most large earthquakes are now commonly reported using the moment magnitude scale (see below).

## How do scientists monitor earthquakes?

Seismic monitoring utilizes sensitive seismographs to record the ground motion from seismic waves created by earthquakes or other sources. Seismograms from seismic monitoring stations can be used to determine the location, origin time, and magnitude (as well as other characteristics) of earthquakes.

## What is earthquake intensity?

The intensity is a number (written as a Roman numeral) describing the severity of an earthquake in terms of its effects on the earth’s surface and on humans and their structures. There are many intensities for an earthquake, depending on where you are, unlike the magnitude, which is one number for each earthquake.

## How are earthquakes classified?

Earthquakes are categorized in two ways – magnitude and intensity. Magnitude indicates the severity of an earthquake using the Richter Scale, a logarithmic, instrumentally determined measurement. The severity of an earthquake is a rating based on the amplitude of the seismic waves.

## Which is classified as a major earthquake?

Major: 7 – 7.9 SUTANTA ADITYA/AFP/Getty A major earthquake registers between 7 and 7.9 on the Richter scale. There are about 20 a year worldwide and they cause very serious damage.

## Which earthquake classified as a major earthquake?

Magnitude Earthquake Effects
5.5 to 6.0 Slight damage to buildings and other structures.
6.1 to 6.9 May cause a lot of damage in very populated areas.
7.0 to 7.9 Major earthquake. Serious damage.
8.0 or greater Great earthquake. Can totally destroy communities near the epicenter.

## What are the two main types of earthquake vibrations?

The two general types of vibrations produced by earthquakes are surface waves, which travel along the Earth’s surface, and body waves, which travel through the Earth.

## Why are aftershocks dangerous?

Aftershocks are dangerous because they are usually unpredictable, can be of a large magnitude, and can collapse buildings that are damaged from the main shock.

2021-05-17