Giuseppe Mercalli (21 May 1850 – 19 March 1914) was an Italian

volcanologist A volcanologist, or volcano scientist, is a geologist who focuses on understanding the formation and eruptive activity of volcanoes. Volcanologists frequently visit volcanoes, sometimes active ones, to observe and monitor volcanic eruptions, col ...

and

Catholic The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

priest A priest is a religious leader authorized to perform the sacred rituals of a religion, especially as a mediatory agent between humans and one or more deities. They also have the authority or power to administer religious rites; in partic ...

. He is known best for the

Mercalli intensity scale The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the ef ...

for measuring

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

intensity.

Biography

Born in

Milan Milan ( , , Lombard: ; it, Milano ) is a city in northern Italy, capital of Lombardy, and the second-most populous city proper in Italy after Rome. The city proper has a population of about 1.4 million, while its metropolitan city ...

, Mercalli was ordained a

Roman Catholic Roman or Romans most often refers to: * Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD * Roman people, the people of ancient Rome *'' Epistle to the Romans'', shortened to ''Romans'', a let ...

priest and soon became a professor of Natural Sciences at the seminary of Milan. The Italian government appointed him a professor at Domodossola, followed by a job at Reggio di Calabria. He was professor of geology at the

University of Catania The University of Catania ( it, Università degli Studi di Catania) is a university located in Catania, Sicily. Founded in 1434, it is the oldest university in Sicily, the 13th oldest in Italy, and the 29th oldest university in the world. With a ...

during the late 1880s and finally was given a job at

Naples University The University of Naples Federico II ( it, Università degli Studi di Napoli Federico II) is a public university in Naples, Italy. Founded in 1224, it is the oldest public non-sectarian university in the world, and is now organized into 26 depar ...

. He was also director of the

Vesuvius Observatory The Vesuvius Observatory ( it, Osservatorio Vesuviano) is the surveillance centre for monitoring the three volcanic areas of Campania, Italy: Mount Vesuvius, the Phlegrean Fields and Ischia. Founded in 1841 on the slopes of Mount Vesuvius by Fe ...

until the time of his death. Vezuviy 1906 apres

Giuseppe Mercalli also observed eruptions of the volcanoes

Stromboli Stromboli ( , ; scn, Struògnuli ) is an island in the Tyrrhenian Sea, off the north coast of Sicily, containing Mount Stromboli, one of the four active volcanoes in Italy. It is one of the eight Aeolian Islands, a volcanic arc north of Si ...

and

Vulcano Vulcano ( scn, Vurcanu) or Vulcan is a small volcanic island belonging to Italy in the Tyrrhenian Sea, about north of Sicily and located at the southernmost end of the seven Aeolian Islands. The island is known for its volcanic activity and ...

in the

Aeolian Islands The Aeolian Islands ( ; it, Isole Eolie ; scn, Ìsuli Eoli), sometimes referred to as the Lipari Islands or Lipari group ( , ) after their largest island, are a volcanic archipelago in the Tyrrhenian Sea north of Sicily, said to be named afte ...

. His descriptions of these eruptions became the basis for two indices of the Volcanic Explosivity Index: 1 – Strombolian eruption, and 2 – Vulcanian eruption. He also photographed

Vesuvius Mount Vesuvius ( ; it, Vesuvio ; nap, 'O Vesuvio , also or ; la, Vesuvius , also , or ) is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of ...

immediately after its eruption in 1906. In 1914, Mercalli burnt to death under suspicious circumstances, allegedly after knocking over a paraffin lamp in his bedroom. He is thought to have been working through the night, as he often did (he once was found working at 11 a.m. when he had set an examination, upon hearing which he replied, "It surely can't be daylight yet!"), when the fatal accident occurred. His body was found, carbonized, by his bed, holding a blanket which he apparently attempted to use to fend off the flames. The authorities, however, stated a few days later that the professor was quite possibly murdered by strangling and soaked in petrol and burned to conceal the crime because they determined that some money (now worth about $1,400) was missing from the professor's apartment.

Intensity scales

Mercalli devised two earthquake intensity scales, both modifications of the

Rossi–Forel scale The Rossi–Forel scale was one of the first seismic scales to represent earthquake intensities. Developed by Michele Stefano Conte de Rossi of Italy and François-Alphonse Forel of Switzerland during the late 19th century, it was used commonly f ...

. The first, now largely forgotten, had six degrees whereas the Rossi–Forel scale had ten. The second, now known as the

, had ten degrees, and elaborated the descriptions in the Rossi–Forel scale. The

is, in modified form, still used. Unlike the

Richter magnitude scale The Richter scale —also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale—is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 p ...

, which measures the energy released by an earthquake, the Mercalli intensity scale measures the effects of an earthquake on structures and people. It is poorly suited for measuring earthquakes in sparsely populated areas but useful for comparing damage done by various tremors and historical earthquakes, and for

earthquake engineering Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures, such as buildings and bridges, with earthquakes in mind. Its overall goal is to make such structures more resistant to earthquakes. An earth ...

. The scale currently in use assigns indices ranging from I ("Not felt, except by a few under favorable conditions"), to XII ("Damage total; objects thrown into the air"). Italian physicist Adolfo Cancani expanded the ten-degree Mercalli scale with the addition of two degrees at the more intense of the scale: XI (catastrophe) and XII (enormous catastrophe). This was later modified by the German geophysicist August Heinrich Sieberg and became known as the Mercalli–Cancani–Sieberg (MCS) scale. This was modified again and published in English by Harry O. Wood and Frank Neumann in 1931 as the Mercalli–Wood–Neumann (MWN) scale. It was later improved by Charles Richter,Eiby G. A., 1966. The Modified Mercalli Scale of Earthquake Intensity and Its Use in New Zealand. N.Z. Journal of Geology and Geophysics, 9, pp. 122-129. developer of the

Richter scale The Richter scale —also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale—is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 ...

References

External links

* {{DEFAULTSORT:Mercalli, Giuseppe 1850 births 1914 deaths Clergy from Milan 19th-century Italian geologists Seismologists Italian volcanologists Earthquake engineering Catholic clergy scientists 19th-century Italian Roman Catholic priests 20th-century Italian Roman Catholic priests Scientists from Milan 20th-century Italian geologists