## What is Rossi-Forel scale used for?

The Rossi–Forel scale was one of the first seismic scales to represent earthquake intensities.

**What measure is described by the Rossi-Forel scale?**

Intensity scales, like the Modified Mercalli Scale and the Rossi-Forel scale, measure the amount of shaking at a particular location. An earthquake causes many different intensities of shaking in the area of the epicenter where it occurs.

**Who invented the Modified Mercalli scale?**

Although numerousintensity scales have been developed over the last several hundred years to evaluate the effects of earthquakes, the one currently used in the United States is the Modified Mercalli (MM) Intensity Scale. It was developed in 1931 by the American seismologists Harry Wood and Frank Neumann.

### What is the Mercalli scale and what does it measure?

The Mercalli Intensity Scale measures the intensity of an earthquake by observing its effect on people, the environment and the earthâ€™s surface.

**What is the difference between the Mercalli and Richter scales?**

While the Mercalli scale describes the intensity of an earthquake based on its observed effects, the Richter scale describes the earthquake’s magnitude by measuring the seismic waves that cause the earthquake.

**What is the weakest intensity scale?**

Intensity I

Scales. The PEIS has ten intensity scales represented in Roman numerals with Intensity I being the weakest and Intensity X being the strongest.

## What scale measures tsunamis?

Richter scale

The Richter scale is a base-10 logarithmic scale, meaning that each order of magnitude is 10 times more intensive than the last one. In other words, a two is 10 times more intense than a one and a three is 100 times greater. In the case of the Richter scale, the increase is in wave amplitude.

**Is Mercalli or Richter better?**

The earthquake and its impact is measured either by using the Mercalli scale or the Richter Scale. The Richter scale is more objective, but the Mercalli scale is subjective. The Mercalli scale bases its measurement on the observed effects of the earthquake and describes its intensity.

**Is the Mercalli scale still used?**

It measures the damage from earthquakes and the observed effects. Lower numbers indicate intensity likely felt by people and higher numbers indicate damage to structures and buildings. The Modified Mercalli Intensity Scale is still used today and can be found in the image below.

### What is the difference between an earthquake’s epicenter and focus?

The focus is the place inside Earth’s crust where an earthquake originates. The point on the Earth’s surface directly above the focus is the epicenter.