Arturo Arias Suárez
He invented a way to measure how much damage an earthquake can do. It is called Arias Intensity and is used in every seismic region of the world.
Measuring an earthquake is harder than it sounds. Magnitude tells you how much energy the fault released, but not how much damage it will do at a given place. Traditional intensity scales solve that by looking at collapsed buildings — which makes them useless where there are no buildings, and misleading where there are but they are poorly built.
In 1970, a Chilean engineer proposed measuring something else: the energy the ground itself receives. It does not depend on what has been built, so it works anywhere. It is called Arias Intensity and it is used in every seismic region of the world.
What Arias Intensity actually is
The definition appeared in Measure of Earthquake Intensity, a chapter in the volume Seismic Design for Nuclear Power Plants, edited by Robert J. Hansen and published by MIT Press in 1970, pages 438 to 483. Arias signed from two institutions: MIT and the Universidad de Chile.
The idea, in simple terms: instead of asking what fell down, you integrate the ground's acceleration over the whole motion. The result is a number that represents the earthquake's destructive capacity at that point, independent of whatever sits on top of it.
found a more elegant and simpler way to measure an earthquake's capacity to cause damage, independent of whether or not structures exist in the area and regardless of the type or quality of construction. This simplicity is what allows Arias Intensity to be applied universally
Rodolfo Saragoni, Universidad de Chile, translated from Spanish
Fifty-five years at the same faculty
Born in Nueva Imperial
On 10 August.
Teaching assistant in Vector Calculus and Rational Mechanics
Faculty of Physical and Mathematical Sciences, Universidad de Chile.
Civil Engineer
Thesis: "Oscillations of an Elevated Tank" ("Oscilaciones de un Estanque Elevado").
Director of IDIEM
The Universidad de Chile's materials and structures testing institute. In this period the IDIEM journal was awarded a Unesco prize.
Creates the Instituto de Matemáticas y Física
Within the same faculty, and directs it.
Visiting professor at MIT
The 1970 chapter comes out of this stay.
Seismic design code NCh 433
Put to the test successfully in the 1985 earthquake.
Academia de Ciencias de Chile
Full member, for his international contributions to earthquake engineering.
Professor Emeritus
Universidad de Chile.
Dies in Santiago
His funeral was held on Monday 12 March at the Cementerio General.
What his students said
With Don Arturo goes a part of the dreams of the young man who wanted to do science… He did not teach a course in rational mechanics, he pointed to a path to follow, a path that began with mechanics but continued on to other, ever more interesting and mysterious wonders.
Armando Cisternas, seismologist, former student, from Paris, translated from Spanish
That same Cisternas features in a scene told in his obituaries: on meeting Atahualpa Yupanqui, the Argentine folk singer, he told him they had something in common —"You sing to the earth, and I listen to the earth sing." It was, in essence, a description of the craft Arias had taught him.
What the sources do not quite settle
Arias Intensity is defined in "Measure of Earthquake Intensity", MIT Press, 1970, pp. 438-483.
Bibliographic reference confirmed in the catalogue of the US Department of Energy (OSTI.GOV).
He was born on 10 August 1923 in Nueva Imperial.
Two independent sources agree.
He died in March 2001.
The faculty magazine's obituary confirms the funeral was held on Monday 12 March at the Cementerio General, but does not give the date of death. Other references give 11 and 12 March. That is why the entry says "March 2001" and not a specific day.
In 2009 the BBC included him among five Latin American scientists who changed the world.
This appears in a secondary source, and the original piece could not be located.
- Facultad de Ingeniería · Universidad de Chile. Semblanza y explicación de la Intensidad de Arias
View source → - Revista de la FCFM · Universidad de Chile. Obituario con cargos, premios y testimonios
View source → - OSTI.GOV · Departamento de Energía de EE.UU.. Registro bibliográfico de «Measure of Earthquake Intensity» (1970)
View source → - MIT Press. Ficha del volumen donde se publicó
View source →
How to cite
This is free to reuse under CC BY 4.0, as long as you give credit.
FísicaEterna. (2026). Arturo Arias Suárez — biography, FísicaEterna. Retrieved [access date] from https://www.fisicaeterna.cl/en/biographies/arturo-arias
@misc{fisicaeterna_arturo_arias,
author = {FísicaEterna},
title = {Arturo Arias Suárez — biography, FísicaEterna},
year = {2026},
url = {https://www.fisicaeterna.cl/en/biographies/arturo-arias},
note = {CC BY 4.0}
}